Contributions to the knowledge of water bugs in Mindoro Island, Philippines, with a species checklist of Nepomorpha and Gerromorpha (Insecta, Hemiptera, Heteroptera).

BACKGROUND: This survey aims to provide an updated species checklist of aquatic and semi-aquatic bugs in the intra-Philippine biogeographic Region of Mindoro. An assessment survey of water bugs (Hemiptera, Heteroptera) was conducted mostly by manual collection in selected areas of Oriental Mindoro from 2017 to 2018, in which some of the collecting activities were undertaken by graduate students of Ateneo de Manila University. NEW INFORMATION: Twenty-nine aquatic and semi-aquatic heteropteran species were documented and some are known island-endemic species or subspecies, including Enithares martini mindoroensis Nieser & Zettel, 1999, Hydrotrephes stereoides mindoroensis Zettel, 2003, Aphelocheirus freitagi Zettel & Pangantihon, 2010, Rhagovelia mindoroensis Zettel, 1994, Rhagovelia raddai Zettel, 1994, Rhagovelia potamophila Zettel, 1996 and Strongylovelia mindoroensis Lansbury & Zettel, 1997, which were found in new areas in the Region. In addition, there are also new records for the Island that have already been documented in other parts of the Philippines, such as the Philippine-endemic Ochterus magnus Gapud & San Valentin, 1977 and Hebrus philippinus Zettel, 2006 and the widely-distributed backswimmers Anisops nigrolineatus Lundblad, 1933 and Anisops rhomboides Nieser & Chen, 1999. Several undescribed specimens and potentially new species are also discussed in this paper. Further surveys in the other parts of Mindoro and in the other regions of the Philippines, are encouraged to produce a comprehensive baseline data of heteropteran species richness in the country. Arthien Lovell Pelingen, Herbert Zettel, Clister V Pangantihon, Kyra Mari Dominique Aldaba, Earl Kevin Fatallo, Jemillie Madonna de Leon, Hendrik Freitag.

Introduction

The order constitutes a large part of the insect fauna, both in terrestrial and aquatic ecosystems in the Philippines (Gapud 1986). The majority of the aquatic forms belong to and (water bugs) under the suborder (true bugs or typical bugs). These water bugs have been relatively well-studied compared to other aquatic macroinvertebrate taxa, mainly due to the comprehensive Philippine Water Bug Inventory Project (Gapud and Zettel 1999). Most of the represented species are Philippine-endemic, many of which are island-endemics. More than 200 species are known from the country, although numerous undescribed, or even undiscovered species still await their formal description. Despite their abundance, were subject to only a few studies in Mindoro. In Lake Naujan, Mindoro, 12 heteropteran species, along with 49 coleopteran species, were documented (Freitag and Pangantihon 2010), while in Lake Manguao Catchment, Palawan, 21 heteropteran species were recorded (Freitag and Zettel 2012). Zettel (2014) documented 85 gerromorphan species from the Island of Luzon, while Pangantihon and Freitag (2016) recorded 31 new island records of coastal and marine-associated heteropteran species from central Visayas and Mindoro. In total, 43 species were recorded from Mindoro in these previous studies. Since then, no published papers dealt with similar faunistic surveys on aquatic and semi-aquatic in any region of the Philippines. Thus, this study aims to update the species list of and of Mindoro. The majority of the survey efforts were accomplished within the scope of a graduate course activity by the junior authors in selected areas of the Island for which a Gratuitous Permit was issued by the Philippine Bureau of Fisheries and Aquatic Resources (BFAR).

Along with field collection from the easily-accessible municipalities of Puerto Galera and Baco, special attention is given to the Baroc River basin in Roxas, which belongs partly to the Key Biodiversity Area (KBA) “69 Hinunduang Mt.” with extremely high critical conservation priority (“EHc”) and high socioeconomic pressure (Ong et al. 2002). This study aims to address the lack of biodiversity data from Mindoro Island. The comprehensive assessment project of the Baroc River basin by the Ateneo Biodiversity Laboratory has led already to the discovery of several interesting aquatic arthropod species (Freitag 2013, Mey and Freitag 2013, Komarek and Freitag 2014, Vidal et al. 2017, Garces et al. 2018, Komarek and Freitag 2020, Pelingen and Freitag 2020). These papers also provide more details on some of the collecting sites.

Materials and methods

Abbreviations and acronyms

ap apterous

asl. above the sea level (elevation)

bra brachypterus

ma macropterous

N nymph

NN nymphs

s.l. sensu lato

s.str. sensu stricto

sp. species

ssp. subspecies

Field Collection

A large proportion of the aquatic and semi-aquatic heteropteran material studied here was collected in rivers and streams of Oriental Mindoro from June 2017 to August 2018. The sampling sites (all from the Province of Oriental Mindoro, Philippines) are summarised in Table 1.

Table 1.

Acronym codes of sampling sites in the Province of Oriental Mindoro as used in the result section.

Code	Municipality/ Barangay	River/Creek/ Tributary	Description	Latitude, Longitude	Elevation (m asl)
301	Puerto Galera	Tagbinai Munti River	hill creek in coconut plantation	13°29'00''N, 120°57'12''E	10
302	Puerto Galera	downstream of Tamaraw Falls	creek in secondary vegetation	13°27'03"N, 120°59'27"E	80
303	Puerto Galera, Calsapa	Tukunan River (“Hidden Paradise”) (Fig. 1C)	medium-sized river in secondary vegetation	13°26'00''N, 120°58'23''E	80
304	Puerto Galera	downstream of Aninuan Falls	creek in secondary vegetation	13°29'10''N, 120°54'18''E	10
305	Puerto Galera	Tagbinai Malaki River(Fig. 1B)	small river in secondary vegetation	13°28'57''N, 120°57'34''E	30
310	Baco, Dulangan	Lantuyan River	torrent mountain river in secondary vegetation	13°16'08''N, 121°04'56''E	55
312	Baco, Dulangan	Lantuyan River	torrent tributary of Lantuyan River in secondary forest	13°18'02"N, 121°02'44"E	400
353	Baco	Baco, Rural Road Side	residual pools of small intermittent river in secondary vegetation	13°21'49''N, 121°05'30''E	26
356	Baco, Dulangan	lower Dulangan River (Fig. 1D)	torrent river in rural open land	13°21'22''N, 121°07'10''E	8
396	Puerto Galera, Poblacion	lowland Creek (Fig. 1A)	small lowland creek in secondary vegetation	13°30'07"N, 120°56'46"E	2
BR2	Roxas, San Mariano	middle Baroc River	disturbed warm water river in farmland	12°37'40"N, 121°26'29"E	10
BR3	Roxas, Wasig	lower Baroc River(Fig. 2A)	disturbed warm water river in farmland	12°35'51''N, 121°28'11''E	2
HBC	Roxas, San Vicente	Quirao Buhay Creek	creek in secondary vegetation	12°36'10''N, 121°23'00''E	142
HBT	Roxas, San Vicente	Tagugoy Creek	small Quirao Buhay tributary in secondary forest	12°36'30''N, 121°22'38''E	200
HTC	Roxas, San Vicente	Tinggiwang Creek	creek in secondary forest	12°35'48''N, 121°22'01''E	162
HQC	Roxas, San Vicente	Quirao na Balete Creek	mountain creek fringed by secondary forest	12°35'38''N, 121°23'34''E	230
HR1	Roxas, San Vicente, Quirao	Hinundungan River	slightly disturbed lowland river in rural extensive farmland and secondary vegetation	12°36'23''N, 121°23'29''E	118
HR2	Roxas, San Vicente	Hinundungan River down-stream of Hinagdanan Falls (Fig. 2B)	clean mountain river in secondary forest	12°35'23''N, 121°21'52''E	200
HR3	Roxas, San Vicente	Hinundungan River up-stream of Hinagdanan Falls	clean mountain river in secondary forest	12°35'10''N, 121°21'36''E	280
TAC	Roxas, San Vicente	Sapang Alupa	torrent creek in old secondary forest	12°37'48''N, 121°20'52''E	340
TDR1	Roxas, San Vicente, Taugad Diit	lower Taugad Daka River	clean mountain river in extensive farmland and secondary forest	12°37'33''N, 121°21'18''E	180
TDR4	Roxas, San Vicente	upper Taugad Daka River (Fig. 2C)	clean mountain creek in secondary forest	12°38'00''N, 121°19'15''E	700
THC	Roxas, San Vicente	Hiyong Creek	perennial creek in extensive farmland and secondary vegetation	12°37'27''N, 121°22'48''E	147
THF	Roxas, San Vicente	Hiyong Fall	small fall of perennial creek in extensive farmland and secondary vegetation	12°37'32''N, 121°22'47''E	150
TIR1	Roxas, San Vicente, Taugad Diit	lower Taugad Diit River	slightly disturbed river in extensive farmland and secondary vegetation	12°37'32"N, 121°22'17"E	180
TR1	Roxas, San Vicente Proper	Taugad River	slightly disturbed lowland river in extensive farmland and secondary vegetation	12°37'07''N, 121°23'37"E	95
TR2	Roxas, San Vicente	upper Taugad River	mountain river in secondary vegetation and forest	12°37'18''N, 121°22'58''E	140
TUC	Roxas, San Vicente	“unnamed” creek(Fig. 2D)	small intermittent creek in secondary forest	12°37'38''N, 121°22'38''E	154
TWC	Roxas, San Vicente Proper	“community water source” creek”	perennial mountain creek in secondary forest	12°37'01"N, 121°23'18"E	150

The main sampling method used was handpicking with the use of a hand-held net to collect the aquatic bugs. Some of the specimens had also been collected using a black light trap (L) or in emergence traps (E) as described by Freitag (2004).

In the label data of the material, the codes mentioned before for the collecting sites are followed by a single minor letter for the microhabitats (Fig. 3) listed and encoded in Table 2.

Figure 3.

Microhabitats sampled with their respective label codes, as listed above. A. side pool with mineral deposits (“t”); B. littoral pool with mineral deposits (“b”); C. bottom gravel in running water (“c”); D. leaf packs trapped in riffles (“d”); E. leaf litter in rivulet (“k”); F. rock surface in riffle (“g”); G. root packs in running water (“h”); H. neustic in running water (“z”).

Table 2.

Microhabitat codes for samples as used in the result section.

Microhabitat code	Description
a	littoral sand/gravel in running sections of the stream/river
b	mud/sand/fine gravel in littoral pool sections with stagnant or very slow-moving water connected to the stream/river (Fig. 3B)
c	stream bottom gravel in running sections of the stream/river (Fig. 3C)
d	leaf packs in running and riffle sections of the stream/river (Fig. 3D)
e	leaf litter/CPOM in isolated side pools or residual pool (separated from stream)
f	submerged wood in running and riffle sections of the stream/river
g	solid rock surfaces in riffle and running sections of the stream/river (Fig. 3F)
h	root packs/grass bunches in running sections of the stream/river (Fig. 3G)
j	hygropetric rocks
k	CPOM/leaf litter in small side rivulets connected to the mainstream (Fig. 3E)
m	gravel/sand in shallow, sun-exposed side pools or residual pool (separated from stream)
t	littoral gravel/sand/mud deposits of side pools or residual pool (separated from stream) (Fig. 3A)
u	water plants inside pools or residual pool (separated from stream)
y	water surface (neustic) of calm water sections (pool)
z	water surface (neustic) of running and riffle water sections (Fig. 3H)

Handling of Material Collected

Specimens collected were preserved in 96% ethanol and stored (-20°C) prior to identification. Morphological examination was done using a dissecting microscope (LEICA EZ4) and a compound microscope (OLYMPUS SZ61). The habitus images were produced using a Canon EOS 6D with macro lens and a stack rack. This stacking of images was operated using Helicon Remote and Helicon Focus. The figures were generated then processed with Adobe Photoshop.

Identification keys and other relevant literature were used for the taxa as stated in the respective taxonomic sections. In some cases, loaned type material from the Natural History Museum Vienna, Austria (NHMW) was used for comparison. The dissected parts and actual specimen were glued on to entomological papers, while some were stored in the vial with ethanol. All material is labelled and kept at the collections of the Biodiversity Laboratory, Ateneo de Manila University (ADMU), National Museum of the Philippines, Museum of Natural History, Manila, Philippines (NMP) and the Museum für Naturkunde Berlin, Germany (ZMB).

Taxon treatments

9845DBEE-65C4-5E64-A78F-0EDE203B95D2

Type status: Other material. Occurrence: individualCount: 2 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Puerto Galera; locationRemarks: 305g; Event: eventDate: 22.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Baco; locationRemarks: 353e; Event: eventDate: 24.08.2017

Taxon discussion

This still unnamed new species (Fig. 4A) of the Dallas, 1850 group (see Dallas 1850, Lansbury 1972) will be described and discussed further in an upcoming paper by Tran and Zettel (in prep.).

Figure 4.

Habitus illustrations of of Mindoro A. sp. ( group); B. ; C. ; D. ; E. ; F. ; G. ; H. . Scale bars A 10 mm B–H 1 mm. A & C © NHMW Image Collection / photo: H. Bruckner, printed with permission.

Habitat

Specimens were found in both flowing and calm littoral sections of shallow streams, such as in Fig. 1B. See Fig. 5 for current records.

Figure 1.

Sampling sites at northern Mindoro (Baco, Puerto Galera). A. the first author sampling at site 396; B. Tagbinai Malaki River (305); C. Tukunan River at "Hidden Paradise" (303); D. lower Dulangan River (356).

Figure 5.

Distribution of the collecting sites of material treated in this study.

Gapud & San Valentin, 1977

C8C613DA-E50D-5E82-89CC-852C48F824D1

Type status: Other material. Occurrence: individualCount: 3 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TIRj; Event: eventDate: 05.07.2017

Distribution

This is the first record of Gapud & San Valentin, 1977 (see Gapud and San Valentin 1977) from Mindoro (Fig. 5). The species is Philippine-endemic, previously only known from Luzon – Mt. Makiling, Laguna; Humayao Creek, Cavite; Quezon; and in La Union (Gapud 2002).

Refer to Gapud (1986) for identification.

The specimens were found on wet rocks.

Gapud, 1981

F36778EB-E735-5BA6-B409-0E2F2EF63C9C

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBT(E); Event: eventDate: 21.09.2017

Type status: Other material. Occurrence: individualCount: 3 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCk; Event: eventDate: 21.09.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQC(E); Event: eventDate: 28.09.2017

Type status: Other material. Occurrence: individualCount: 4 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TWCj; Event: eventDate: 23.09.2017

This species (Fig. 4B) is widely distributed in the Philippines. See Fig. 5 for our additional records.

Refer to Gapud (1981) for identification. In Mindoro, three species of Latreille, 1807 are recorded so far, Rieger, 1977, Gapud, 1981 and Kormilev, 1971 (Kormilev 1971, Gapud 1995, Gapud 2002).

We collected specimens in emergence traps spanned over littoral portions of small streams, on hygropetric rocks and along small rivulets. The species is generally found in banks of streams, ponds, lakes, freshwater marshlands and in association with waterfalls. It is also found in substrates that are muddy or sandy.

6CD92895-F3EB-5B65-A5D4-9E3B0674434B

Type status: Other material. Occurrence: individualCount: 18 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR2(L); Event: eventDate: 31.06.2017

Type status: Other material. Occurrence: individualCount: 4 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR1(L); Event: eventDate: 13.07.2017

Type status: Other material. Occurrence: individualCount: 2 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2(L); Event: eventDate: 21.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2(L); Event: eventDate: 20.08.2018

The species cannot be identified yet because the examination of comparative type material is needed, which is currently inaccessible. Nieser and Chen (2003) described four species from the Philippines but the Mindoro specimens differ from those.

All specimens were collected using a light trap, so their habitat cannot be accurately described. However, species of Kirkaldy, 1897 are usually found in stagnant or shallow, slowly flowing waters (Nieser 1999). See Fig. 5 for current records, amongst them is site HR2 (Fig. 2B).

Figure 2.

Sampling sites at the Baroc River basin (Roxas, southern Mindoro). A. lower Baroc River (BR3); B. Hinundungan River from Hinagdanan Falls (HR2); C. upper Taugad Daka River (TDR4); D. small tributary of the Taugad River (TUC).

Zettel & Nieser, 1999

EAC5BABD-8DB0-57BC-BB7C-B9661DE764AC

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Puerto Galera; locationRemarks: 303b2; Event: eventDate: 06/07/2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Baco; locationRemarks: 310c; Event: eventDate: 08/22/2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Baco; locationRemarks: 312f1; Event: eventDate: 08/22/2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBCa; Event: eventDate: 06/20/2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBTc; Event: eventDate: 07/05/2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCc; Event: eventDate: 06/16/2017

Type status: Other material. Occurrence: individualCount: 18 males (bra), 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCc; Event: eventDate: 06/30/2017

Type status: Other material. Occurrence: individualCount: 2 males (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCh; Event: eventDate: 09/26/2017

Type status: Other material. Occurrence: individualCount: 3 males (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR1c; Event: eventDate: 06/17/2017

Type status: Other material. Occurrence: individualCount: 5 males (bra), 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR1c; Event: eventDate: 07/08/2017

Type status: Other material. Occurrence: individualCount: 2 males (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR2c; Event: eventDate: 07/03/2017

Type status: Other material. Occurrence: individualCount: 3 males (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR2d; Event: eventDate: 12/06/2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR3c; Event: eventDate: 31.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR3c; Event: eventDate: 03/31/2018

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HTCc; Event: eventDate: 07/03/2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HTCf; Event: eventDate: 12/28/2017

Type status: Other material. Occurrence: individualCount: 2 males (bra), 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TDR1c; Event: eventDate: 06/18/2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TDR1f; Event: eventDate: 07/08/2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TDR1f; Event: eventDate: 06/18/2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TDR1f; Event: eventDate: 09/22/2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TDR1c; Event: eventDate: 04/04/2018

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: THCf; Event: eventDate: 06/23/2017

Type status: Other material. Occurrence: individualCount: 2 males (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: THCd; Event: eventDate: 11/17/2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TIR1d; Event: eventDate: 12/05/2017

Type status: Other material. Occurrence: individualCount: 2 males (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TIR1d; Event: eventDate: 09/22/2017

Type status: Other material. Occurrence: individualCount: 2 males (bra), 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR1h; Event: eventDate: 07/02/2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR1d; Event: eventDate: 09/22/2017

Type status: Other material. Occurrence: individualCount: 3 males (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2f; Event: eventDate: 06/14/2017

Type status: Other material. Occurrence: individualCount: 3 males (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2c; Event: eventDate: 07/03/2017

Type status: Other material. Occurrence: individualCount: 2 males (bra), 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2d; Event: eventDate: 07/07/2017

Type status: Other material. Occurrence: individualCount: 2 males (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2h; Event: eventDate: 11/17/2017

This subspecies is endemic to Mindoro (Zettel et al. 1999). See Fig. 5 for new records.

For identification, refer to the key by Zettel et al. (1999), a habitus illustration is provided in Fig. 4C. The genus is endemic to the Philippines (Zettel et al. 1999). All material treated in here is brachypterous.

Zetttel & Nieser, 2009 Fig. 4C is found in middle-sized streams running through secondary rainforest (Fig. 2B), as well as large, fast flowing streams, partly in secondary vegetation (Fig. 1C), but then only downstream of forested areas (Zettel et al. 1999). The specimens were retrieved in more or less fast flowing water from several substrates, foremost gravel, but also wood, leaf litter and root packs (Fig. 3G).

Zettel & Pangantihon, 2010

3FCEDFAD-987F-538B-AAEF-186925E7E5F6

Type status: Other material. Occurrence: individualCount: 1 (N); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Baco; locationRemarks: 356c; Event: eventDate: 29.08.2017

Type status: Other material. Occurrence: individualCount: 2 (NN); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: BR3m; Event: eventDate: 04.12.2017

Type status: Other material. Occurrence: individualCount: 7 males (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: BR3b; Event: eventDate: 22.07.2017

Type status: Other material. Occurrence: individualCount: 4 males (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR1e; Event: eventDate: 17.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR2e; Event: eventDate: 03.07.2017

Type status: Other material. Occurrence: individualCount: 1 female (bra); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TDR1c; Event: eventDate: 18.06.2017

Type status: Other material. Occurrence: individualCount: 1 (N); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR1f2; Event: eventDate: 21.08.2017

Zettel and Pangantihon, 2010 (see Zettel and Pangantihon 2010) (Fig. 4D) is endemic to Mindoro and was previously only known from its type locality, Malayas River in Victoria, Oriental Mindoro (Zettel and Pangantihon 2010). Here we present the first records from Baco and Roxas (Fig. 5).

For identification, refer to Zettel and Pangantihon (2010).

species Westwood, 1883 thrives in rather large, fast flowing rivers (Fig. 1D; Fig. 2A and B) with substrates consisting of a mixture of gravel and sand. The species is a typical benthic bottom dweller.

Matsumura, 1915

893A74AB-3951-52CC-8475-FAEC8983B375

Type status: Other material. Occurrence: individualCount: 1 male (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2(L); Event: eventDate: 03.07.2017

The species (Fig. 4E) is known from Luzon, Catanduanes, Leyte, Mindoro (with an additional record, see Fig. 5), Negros, Palawan, Burias, Bohol, Panay, Samar, Siargao and Mindanao (Zettel et al. 2012). It is also a widespread species in the Oriental realm with records from India, southern China, Iriomote (off Japan), Melaka, and Batu Berendam, Malaysia (Nieser 2004).

For identification, refer to the key by Zettel (2003a) and the original description (Matsumura 1915).

The single specimen was collected using a light trap not allowing for a specific microhabitat association. In general, representatives of this genus are found in isolated side pools (Fig. 3A) of streams and other stagnant water bodies (Zettel 2003a).

Lundblad, 1933

95622298-D41B-57DE-AED1-785534B6F13B

Type status: Other material. Occurrence: individualCount: 1 male (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: THCt; Event: eventDate: 25.06.2017

Lundblad, 1933 (see Lundblad 1933) is widely distributed from India, Myanmar, Thailand, Brunei, Java and up to the Philippines (Zettel et al. 2012), with only a single previous record from Sibuyan Island (Nieser and Chen 1999). This is the first record from Mindoro Island (Fig. 5).

For identification, refer to the key by Zettel (2003a).

The specimen was found in a small side pool near a slow-flowing stream.

Nieser & Chen, 1999

14276503-3C24-5ED3-8AA6-04CD4CFC4E69

Type status: Other material. Occurrence: individualCount: 4 males (ma), 3 (NN); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Baco; locationRemarks: 353u1; Event: eventDate: 24.08.2017

The species (Fig. 4F) is recorded from Brunei, Borneo, Sulawesi and the Philippines (Nieser and Chen 1999, Chen et al. 2005). Previous Philippine records refer to Leyte, Mindanao, Palawan and Tawi Tawi (Zettel et al. 2012). This is the first record from Mindoro (Fig. 5).

For identification, refer to the key by Zettel (2003a). Its specific epithet, , refers to the lozenge-shaped fossa on the tylus (Nieser and Chen 1999), which is a good character for identification.

Nieser & Chen, 1999 (see Nieser and Chen 1999) is found in a variety of shallow, stagnant freshwater bodies, such as lakes, ponds, carabao puddles, marsh land and moats (Nieser and Chen 1999).

Nieser & Zettel, 1999

BD861D2C-85F6-5E28-9A3C-D97DBACB4E60

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Puerto Galera; locationRemarks: 304b; Event: eventDate: 07/25/2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBTk; Event: eventDate: 09/21/2017

Type status: Other material. Occurrence: individualCount: 6 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCe; Event: eventDate: 06/30/2017

Type status: Other material. Occurrence: individualCount: 4 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCb; Event: eventDate: 06/30/2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TIRe; Event: eventDate: 07/10/2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TIRb; Event: eventDate: 09/22/2017

Type status: Other material. Occurrence: individualCount: 2 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TWCy; Event: eventDate: 06/25/2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TWCb; Event: eventDate: 09/23/2017

This species (Fig. 4G) is widely distributed in the Philippines, but the subspecies is endemic to Mindoro (Nieser and Zettel 1999). See Fig. 5 for the new records.

For identification, refer to the key by Nieser and Zettel (1999).

Nieser & Zettel, 1999 (see Nieser and Zettel 1999) can be found in calm shores and connected and isolated pools on the banks of streams (Nieser and Zettel 1999, current study).

Zettel, 2003

77CFE4BB-D1EE-5F48-8E6B-E577E26042CE

Type status: Other material. Occurrence: individualCount: 13 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR2f; Event: eventDate: 07/03/2017

Type status: Other material. Occurrence: individualCount: 2 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TACb; Event: eventDate: 07/09/2017

Type status: Other material. Occurrence: individualCount: 2 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TDR1f; Event: eventDate: 09/22/2017

Type status: Other material. Occurrence: individualCount: 3 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TIR1b; Event: eventDate: 07/10/2017

The subspecies (Fig. 4H) is endemic to Mindoro Island. See Fig. 5 for new records. Other Zettel, 2003 (see Zettel 2003b) subspecies occur in north and central Luzon, namely ssp. and ssp. .

For identification, refer to the key by Zettel (2003b).

Zettel, 2003 is mainly associated with lentic sections of running waters, swimming actively at the edges of plant material, rarely benthic in running waters. We found most specimens attached to wood in clean mountain rivers.

Zettel, 2006

E160ED30-1B8D-56EE-A57F-E6191D0A0AC7

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Puerto Galera; locationRemarks: 302j; Event: eventDate: 25.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBTj; Event: eventDate: 05.07.2017

Type status: Other material. Occurrence: individualCount: 5 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: THFj; Event: eventDate: 07.07.2017

Type status: Other material. Occurrence: individualCount: 7 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TIR1b; Event: eventDate: 22.09.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR1j; Event: eventDate: 13.07.2017

Type status: Other material. Occurrence: individualCount: 2 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2j; Event: eventDate: 07.07.2017

Type status: Other material. Occurrence: individualCount: 3 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2j; Event: eventDate: 23.09.2017

Type status: Other material. Occurrence: individualCount: 5 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TWCj; Event: eventDate: 23.09.2017

The species is widely distributed in the Philippines, except for Palawan. This is the first record of this species in Mindoro (Fig. 7). It was previously recorded from Biliran, Bohol, Camiguin, Catanduanes, Cebu, Leyte, Luzon, Masbate, Mindanao, Negros, Panay, Polillo, Poro, Samar and Siquijor (Zettel 2006).

Figure 7.

Distribution of the collecting sites of material (part 1) treated in this study.

For identification, see Zettel (2006). The parameres have long setae both in the lateral and apical portions. Most of the species have straight parameres and only few were directed mesally. In contrast to the complex, this species has a less distinct endocorium with only a small and elongate white spot. All specimens examined were macropterous.

Zettel, 2006 (see Zettel 2006) is quite euryoecious and can also thrive in anthropologically-disturbed habitats. It is commonly found on the banks of running waters and more rarely in nearby stagnant waters. Unlike other species, it is often found in sunny and dry areas. We obtained most records from hygropetric microhabitats.

D039B35A-7129-5B7B-9885-49747E9E41E1

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: BR2b; Event: eventDate: 29.12.2017

Type status: Other material. Occurrence: individualCount: 2 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBCg; Event: eventDate: 30.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBTb; Event: eventDate: 12.08.2017

Type status: Other material. Occurrence: individualCount: 2 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBT(E); Event: eventDate: 21.09.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCk; Event: eventDate: 21.09.2017

Type status: Other material. Occurrence: individualCount: 5 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCb; Event: eventDate: 21.09.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR1a; Event: eventDate: 01.07.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TIR1b; Event: eventDate: 22.09.2017

The complex is discussed by Zettel (2004a), Zettel (2006). Due to the lack of specimens for comparison, our material (Fig. 6A) cannot be identified to species level. All specimens examined were macropterous.

Figure 6.

Selected habitus illustrations of of Mindoro A. sp.; B. ; C. ; D. ; E. ; F. ; G. ; H. . Scale bars 1 mm.

The specimens (Fig. 7) were found at the banks of more or less fast flowing sections of rivers of small to medium size.

Lundblad, 1933

E9060408-1B1D-5E31-9483-247930AC66C7

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Baco; locationRemarks: 353u; Event: eventDate: 24.08.2017

Type status: Other material. Occurrence: individualCount: 6 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBCb; Event: eventDate: 08.07.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2j; Event: eventDate: 08.07.2017

Type status: Other material. Occurrence: individualCount: 2 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2e; Event: eventDate: 10.08.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2b; Event: eventDate: 23.09.2017

(s.l.) Lundblad, 1933 (see Lundblad 1933) was reported from Australia, China, India, Indonesia, Japan, Malaysia, Philippines (see Fig. 7 for new records), Sri Lanka, Singapore, Thailand, and Vietnam (Lundblad 1937, Chandra and Jehamalar 2011, Yang and Murphy 2011, Zettel 2014).

For identification, refer to the key by Yang and Murphy (2011). More recently, Jehamalar et al. (2019) have shown that consists of a complex of closely-related species. At least two species of this complex occur in the Philippines. Their correct names remain uncertain. As a result, we refrain from concluding that the previous records from other areas in the Philippines and specimens in this study are indeed .

Lundblad, 1933 is common in plains and mountains in stagnant, slow flowing and even in brackish water (Yang and Murphy 2011). We found the species in similar, partly identical habitats like , but so far, never syntopic with the former species.

Horváth, 1895

75557FDA-8376-5DEC-9B8A-97335AAA3DDC

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Puerto Galera; locationRemarks: 305a; Event: eventDate: 24.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR2; Event: eventDate: 03.07.2017

Type status: Other material. Occurrence: individualCount: 4 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TDR1b; Event: eventDate: 05.07.2017

Type status: Other material. Occurrence: individualCount: 4 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: THFj; Event: eventDate: 07.07.2017

Type status: Other material. Occurrence: individualCount: 11 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR1b; Event: eventDate: 13.07.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2j; Event: eventDate: 23.09.2017

Type status: Other material. Occurrence: individualCount: 2 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TWCb; Event: eventDate: 06.07.2017

Type status: Other material. Occurrence: individualCount: 2 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TWCj; Event: eventDate: 23.09.2017

The species (Fig. 6B) is widely distributed in the tropics and subtropics of the Old World, including the Philippines (Zettel 2014). See Fig. 7 for additional records.

For identification, refer to the key by Yang and Murphy (2011). All specimens examined were apterous.

species are commonly found amongst marginal vegetation in standing waters of ponds and streams. Horváth, 1895 (see Horváth 1895) can also be found in brackish-water habitats (Yang and Murphy 2011). We found several specimens on shaded, wet rocks and at the stream littoral with mineral substrates (Fig. 1B).

Eschscholtz, 1822

389B5EBF-D7C2-5F3F-8E8A-A733ABA4D1E6

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR1b; Event: eventDate: 01.07.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR3y; Event: eventDate: 21.06.2017

Type status: Other material. Occurrence: individualCount: 2 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TIR1b; Event: eventDate: 30.06.2017

Eschscholtz, 1822 (see Eschscholtz 1822) is widely distributed in the Philippines (see Fig. 7 for new records), the Oriental Realm, Wallacea and New Guinea (Polhemus and Lansbury 1997, Gapud et al. 2003).

For identification, refer to the key by Gapud et al. (2003). All specimens examined were macropterous.

The species is often found in large stagnant water bodies and rarely seen in running waters; however, all our samples are from stream banks.

Polhemus, 1976

319A7012-BF23-5945-8981-C44B68403179

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Puerto Galera; locationRemarks: 305h; Event: eventDate: 24.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCy; Event: eventDate: 30.06.2017

Type status: Other material. Occurrence: individualCount: 5 males (ap, ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCb; Event: eventDate: 21.09.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: THFj; Event: eventDate: 07.07.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2j; Event: eventDate: 08.07.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TWC2y; Event: eventDate: 25.06.2017

Polhemus, 1976 (in Polhemus and Reisen 1976) (Fig. 6C) is a widespread species in the Philippines and neighbouring areas (Borneo, Sulawesi, New Guinea) (Polhemus and Lansbury 1997, Gapud et al. 2003).

For identification, refer to the key by Gapud et al. (2003).

This species can be found in both stagnant waters and edges of streams and rivers (Gapud et al. 2003). We found the species in shaded hygropetric sites and at stream banks with mineral and organic substrates (Fig. 1B).

Scott, 1874

E3D61488-A5E2-57FF-B7AB-FCA2AB95FC7D

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: BR3m; Event: eventDate: 08.07.2017

Type status: Other material. Occurrence: individualCount: 10 males (ma), 18 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2e; Event: eventDate: 23.09.2017

This species (Fig. 6D), which was originally described from Japan (Scott 1874), is widely distributed in the Oriental, Australian and Melanesian Regions reaching eastwards to the remote islands of the West Pacific Region (Andersen and Weir 2003). See Fig. 7 for the additional records.

See Andersen et al. (2002) for identification. The species is rarely collected in the Island.

The species was found on stream banks, specifically in side pools (Fig. 3B), such as at site BR3 (Fig. 2A).

Hecher, 2006

7D1A3A31-6FCA-5453-9F33-F8E18D3E1779

Type status: Other material. Occurrence: individualCount: 2 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBCg; Event: eventDate: 30.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TDR1h; Event: eventDate: 04.07.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: THCe; Event: eventDate: 07.07.2017

Type status: Other material. Occurrence: individualCount: 6 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TIR1b; Event: eventDate: 22.09.2017

The typical form is only known from the Mountain Province in northern Luzon (Hecher 2006). See Fig. 7 for the collecting sites of the slightly varying Mindoro material.

The specimens (Fig. 6E) closely resemble those of Hecher, 2006 following the key in Hecher (2006), displaying the following characters: first metatarsal segment devoid of a tuft of very long setae basally; first and second metatarsal segment with a row of long setae over entire length; and metatarsus about half as long as metatibia. However, the pygophore of males has long, bristle-like setae on its caudo-lateral margin like Hecher, 2006. Given the lack of any records, except for the specimens in hand and the type material from northern Luzon, it must remain unsolved if the material is conspecific or represents a new, but related species. This variation is only recognised in our specimens from Mindoro.

The specimens were found at banks of creeks and rivers, both in calm and flowing sections.

Lansbury & Zettel, 1997

3A122150-3696-5528-8B86-E2CC8EBD1111

Type status: Other material. Occurrence: individualCount: 3 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Baco; locationRemarks: 353u; Event: eventDate: 24.08.2017

Type status: Other material. Occurrence: individualCount: 2 males (ma, ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCy; Event: eventDate: 21.09.2017

Lansbury & Zettel, 1997 (see Lansbury and Zettel 1997) (Fig. 6F) is endemic to Mindoro and only known from the type locality in Puerto Galera (Lansbury and Zettel 1997) and our records from Baco and Roxas (Fig. 7).

For identification, refer to the key by Zettel (2003c).

The species was found in slow flowing water and a residual pool with floating plants.

Zettel, 1994

D3008ACE-CC9E-563C-A12E-37299BF26F81

Type status: Other material. Occurrence: individualCount: 2 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Puerto Galera; locationRemarks: 304b; Event: eventDate: 24.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR3e; Event: eventDate: 19.06.2017

Type status: Other material. Occurrence: individualCount: 2 males; Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TDR1y; Event: eventDate: 23.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TDR4y; Event: eventDate: 04.07.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: THCy; Event: eventDate: 29.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TWCt; Event: eventDate: 25.06.2017

(Fig. 6G) is an endemic species in Mindoro (Zettel 1994). See Fig. 8 for our additional records.

Figure 8.

Distribution of the collecting sites of material (part 2) treated in this study.

For identification, see Zettel (1994).

Zettel, 1994 (see Zettel 1994) is usually found in secondary forests and in anthropogenic terrains close to the coast. They particularly inhabit still waters sections of streams (Zettel 1994). We also found it in small side pools of medium-sized rivers and creeks. The collection at site TDR4 (Fig. 2C) at 700 m altitude is surprising.

Zettel, 1994

48C781DC-C9C4-59A2-8620-DDB10DA8140A

Type status: Other material. Occurrence: individualCount: 4 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCz; Event: eventDate: 30.06.2017

Type status: Other material. Occurrence: individualCount: 4 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCy; Event: eventDate: 23.09.2017

Zettel, 1994 (see Zettel 1994) (Fig. 6H) is endemic to Mindoro (Zettel 1994). See Fig. 8 for additional records.

For identification, see Zettel (1994).

The species is commonly found in moderately fast flowing creeks and lotic sections of the river (Zettel 1994), such as in our study.

Zettel, 1996

5E8DA30D-6C18-5472-AC3D-75C018D0184A

Type status: Other material. Occurrence: individualCount: 2 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Puerto Galera; locationRemarks: 305z; Event: eventDate: 22.06.2017

Zettel, 1996 (see Zettel 1996) is endemic to Mindoro (Freitag and Pangantihon 2010). We present one additional record (Fig. 8).

For identification, see Zettel (1996), a habitus illustration is provided in Freitag and Pangantihon (2010).

The specimens were found neustic on flowing water near root packs of a small river in a rural area (Fig. 1B).

Breddin, 1905

A37DEA25-9529-5B37-BEC6-7C9D85EBD799

Type status: Other material. Occurrence: individualCount: 4 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Baco; locationRemarks: 353u1; Event: eventDate: 24.08.2017

Breddin, 1905 (see Breddin 1905) is a widespread species in southern and south-eastern Asia and Micronesia (Polhemus and Karunaratne 1993). In the Philippines, is distributed throughout the country, but the limits of its distribution in the Philippines are still unclear (Zettel 2014). See Fig. 8 for the additional record.

For identification, refer to the key by Polhemus and Karunaratne (1993).

The specimens were found amongst floating water plants in a residual pool of a dried-up lowland creek in a rural area.

(Mayr, 1865)

9341040E-4DB8-58EB-A131-529E30732405

Type status: Other material. Occurrence: individualCount: 3 males (ap), 4 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBCy; Event: eventDate: 08.07.2017

The species (Fig. 9A) is widespread in the Philippines, Maldives, India, Sri Lanka, southern China and Indonesia (Damgaard et al. 2014), with the first records from Cambodia recently documented by Zettel et al. (2017). See Fig. 8 for our additional records.

Figure 9.

Selected habitus illustrations of of Mindoro A. ; B. ; C. sp. (mutilated specimen); D. ; E. . Scale bars 10 mm.

Refer to Cheng et al. (2001) for the identification.

In the Oriental realm, most species of Stål, 1868 prefer sheltered places in standing waters, which makes them somewhat gregarious. (Mayr, 1865) (see Mayr 1865) and (Fabricius, 1775) (see Fabricius 1775) are probably the only Oriental species of the genus that successfully colonise intermittent habitats.

Mayr, 1865

E9CE3AAE-5019-50EE-BDC4-AE864C7A3DEE

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Puerto Galera; locationRemarks: 304b; Event: eventDate: 07/24/2017

Type status: Other material. Occurrence: individualCount: 2 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCb; Event: eventDate: 06/30/2017

Type status: Other material. Occurrence: individualCount: 3 males (ma), 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCc; Event: eventDate: 06/30/2017

Type status: Other material. Occurrence: individualCount: 3 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TDR1b; Event: eventDate: 06/23/2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TDR4c; Event: eventDate: 07/04/2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: THCb; Event: eventDate: 06/25/2017

Type status: Other material. Occurrence: individualCount: 1 female (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: THCb; Event: eventDate: 06/29/2017

Type status: Other material. Occurrence: individualCount: 5 males (ap), 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TIR1b; Event: eventDate: 09/22/2017

Type status: Other material. Occurrence: individualCount: 4 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR3e; Event: eventDate: 06/19/2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TUCb; Event: eventDate: 11/17/2017

Type status: Other material. Occurrence: individualCount: 2 males (ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TWCt; Event: eventDate: 06/25/2017

Type status: Other material. Occurrence: individualCount: 3 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TWCb; Event: eventDate: 09/23/2017

Mayr, 1865 (see ) (Fig. 9B) is endemic and widespread in the Philippines. Records are available from Biliran, Bohol, Camiguin, Guimaras, Leyte, Luzon, Mindanao, Mindoro (see Fig. 8 for our additional records), Negros, Panay, Polillo, Sibuyan, Tablas, Ticao, as well as unpublished records from Masbate (Zettel 2014 and references therein).

For identification, refer to Zettel (2004b).

Mayr 1865 is amongst the most widespread and abundant of Philippine running waters (Zettel 2004b, Zettel 2014). It exhibits higher tolerance to environmental disturbances in streams than other species. However, we recorded it predominantely from clean streams (Fig. 2C, D). Lentic sections of very small to medium-sized streams and pools associated with running water are its typical habitats (Zettel 2014).

33A024D9-48D1-54ED-8C94-13777D73E6DE

Type status: Other material. Occurrence: individualCount: 2 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Puerto Galera; locationRemarks: 301y; Event: eventDate: 22.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBCy; Event: eventDate: 08.07.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TWCy; Event: eventDate: 25.06.2017

This genus is in need of revision (Zettel 2014). The specimens (Fig. 9C) probably belong to a new species related to Hungerford & Matsuda, 1958 (see Hungerford and Matsuda 1958), from Luzon. The genus is widespread throughout the Afrotropical, Oriental and Australian Regions, extending eastwards up to Fiji (Damgaard et al. 2014). Fifteen species are known in the Malesian Region, including the Philippines (Chen et al. 2005).

The collected specimens were found in small forest streams, a common habitat of representatives of the genus.

(Kirkaldy, 1909)

B8310F72-DA2B-54E7-A7F2-D3F3EBA69ACE

Type status: Other material. Occurrence: individualCount: 4 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Puerto Galera; locationRemarks: 301y; Event: eventDate: 22.06.2017

Type status: Other material. Occurrence: individualCount: 4 males (ap), 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Puerto Galera; locationRemarks: 305y; Event: eventDate: 24.06.2017

Type status: Other material. Occurrence: individualCount: 2 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Puerto Galera; locationRemarks: 396y; Event: eventDate: 02.07.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBCb; Event: eventDate: 08.07.2017

Type status: Other material. Occurrence: individualCount: 6 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCz; Event: eventDate: 30.06.2017

Type status: Other material. Occurrence: individualCount: 3 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCy; Event: eventDate: 30.06.2017

Type status: Other material. Occurrence: individualCount: 7 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HR3b; Event: eventDate: 31.06.2017

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TIRb; Event: eventDate: 22.09.2017

Type status: Other material. Occurrence: individualCount: 6 males (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: TR2y; Event: eventDate: 25.02.2017

(Kirkaldy, 1909) (see Kirkaldy 1909) (Fig. 9D) is endemic to the Philippines and has been recorded from Luzon, Mindanao, Mindoro (Freitag and Pangantihon 2010, see Fig. 8 for additional records), Negros and Panay (Chen and Nieser 2002). Some unpublished records from Catanduanes, Marinduque, Sibuyan, Ticao, Cebu, Samar, Leyte, Mindanao, Siquijor and Poro have also been recognised belonging to this species (Zettel 2014).

For identification, refer to Chen and Nieser (2002).

The specimens were collected from the surface and littoral of calm and moderately fast flowing creeks and medium-sized rivers (Fig. 1A, B). In general, Kirkaldy, 1909 species inhabit mountain streams, creeks and waterfalls in the Oriental Region, specifically the shaded, steady slow-lotic sections of such watercourses (Chen et al. 2005).

Esaki, 1926

AA805018-22B7-5516-A832-EA33793531EE

Type status: Other material. Occurrence: individualCount: 1 female (ap); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HBTb; Event: eventDate: 12.08.2017

Type status: Other material. Occurrence: individualCount: 3 males (ap, ma); Taxon: scientificName: ; Location: island: Mindoro; country: Philippines; municipality: Roxas; locationRemarks: HQCy; Event: eventDate: 21.09.2017

Esaki, 1926 (see Esaki 1926) (Fig. 9E) is a widspread species in western India, southern China, mainland southeast Asia, Sumatra, Java and Borneo, but only known so far from Mindoro and Greater Palawan, in the Philippines (Chen and Nieser 1993, Freitag and Zettel 2012).

For identification, refer to Chen and Nieser (1993).

Quiet bays of smoothly-flowing streams and the edge of large rocks in the middle of streams are the preferred habitats of Mayr, 1865 species (Chen and Nieser 1993), such as the records presented here (Fig. 8).

Checklists

Checklist of the of Mindoro

Fabricius, 1790

9679C066-190B-5142-B0D7-1AEE8F053340

Distribution

Philippine-endemic

Notes

undescribed species

Gapud, 1981

1E19F2BC-96DA-5A77-B96F-DE285F0EF8F9

https://www.gbif.org/species/9451187

Philippine-endemic

Gapud & San Valentin, 1977

6E2710AC-28B0-5BF4-B570-9EC5371B112F

https://www.gbif.org/species/9564741

Philippine-endemic

new Mindoro record

Rieger, 1977

49088337-B1BA-52F7-8BF7-FB4D8FD5BD87

https://www.gbif.org/species/9636304

Philippine-endemic

Gapud, 1977

6A82C8A2-AB56-5403-BDF4-ED094200C969

https://www.gbif.org/species/9344209

Philippine-endemic

Breddin, 1905

9469CBCE-591B-57E0-A537-0740E3D3896C

https://www.gbif.org/species/4781040

Kirkaldy, 1897

DEB8B491-3078-5A71-9031-049D1884C762

unidentified species

Zettel & Nieser, 1999

4BBCC3A5-CAD0-5F80-A674-EC680CE72E3E

https://www.gbif.org/species/9414246

Mindoro-endemic

Zettel & Pangantihon, 2010

EC9EDCB4-23F8-5B38-8887-4A838BD98D16

https://www.gbif.org/species/9307826

Mindoro-endemic

Matsumura, 1915

61D1201D-83FE-5017-9097-8F956BFDBBCC

https://www.gbif.org/species/2020497

Lundblad, 1933

728576DA-67D7-5914-88FD-F46439F58856

https://www.gbif.org/species/10548908

new Mindoro record

Nieser & Chen, 1999

EB448517-167B-5AF0-81FC-2EA5817179BC

https://www.gbif.org/species/9030290

new Mindoro record

Kirkaldy, 1897

112B0489-0C2D-544E-88AD-709C46D3B6F5

https://www.gbif.org/species/4780156

Kirkaldy, 1901

2386149A-82C5-54AE-9E42-609932DA68B3

https://www.gbif.org/species/5813019

Brooks, 1948

BEBA996A-F495-5540-A72A-CD35FC7FC695

https://www.gbif.org/species/8823438

Nieser & Zettel, 1999

F0FC9EC7-E02D-5176-A615-89B5EC5BB1F5

https://www.gbif.org/species/10363548

Mindoro-endemic

Zettel, 2003

26B234CD-3275-515F-A8B0-A35B05D4F4F0

https://www.gbif.org/species/9598999

Mindoro-endemic

Porter, 1954

F21EE14B-78B9-559F-BAF6-F498A1B2D521

https://www.gbif.org/species/9464372

Philippine-endemic

Porter, 1959

F90E55BC-F9E7-5D43-B84A-B99F51A81120

https://www.gbif.org/species/9015705

Philippine-endemic

unpublished records as stated by Zettel (2014)

Zettel, 2006

BB204543-76C3-5C90-9159-79A4AB951EB8

https://www.gbif.org/species/9619952

Philippine-endemic

new Mindoro record

Curtis, 1833

9DB33643-0676-5394-8C3C-FF9A073C6BC7

unidentified species of the complex

Lundblad, 1933

6698FD98-9A91-54EF-83DC-451BC8207F1E

Possibly an undescribed species of the complex

Horváth, 1895

151DD3A6-8182-5DCC-B701-554CB135E61D

Hungerford & Evans, 1934

7A710BD8-B155-5825-BA73-10DFF1D2C376

Eschscholtz, 1822

B0C32F18-FDAA-5143-A289-151F25598D3E

https://www.gbif.org/species/9293320

Polhemus, 1976

C8A7BE0A-F220-57B0-A126-F0897CC1C110

https://www.gbif.org/species/9615221

Lundblad, 1933

926FAD4A-DA34-507C-B16D-B7B65B019F72

https://www.gbif.org/species/9499832

Scott, 1874

D63CC2ED-F6E7-556D-A823-D83A8B200551

https://www.gbif.org/species/6130046

Hecher, 2006

B9B8BFCC-547C-5CDB-8549-F391ACB01A2F

New Mindoro record, varies slightly from the typical form from north Luzon

Esaki, 1926

56FDEF47-5493-5E74-A184-38F35CFA6C4D

https://www.gbif.org/species/6454022

Andersen, 1989

A46055DA-3751-55CC-8274-3E5E046E58EE

https://www.gbif.org/species/6454007

Zettel, 1998

8467593A-17B9-5C5D-8ABC-187339F9C479

https://www.gbif.org/species/8159203

Philippine-endemic

Lansbury & Zettel, 1997

D23BD87F-B72E-5206-BB47-9F99070A64C9

https://www.gbif.org/species/9240789

Mindoro-endemic

Esaki, 1930

5AFCEAA5-0C0A-5124-8C95-85EED3001A3A

unidentified species as stated by Pangantihon et al. (2016)

Drake & Hoberlandt, 1953

C5D509C1-678D-5B64-B78E-37C0107C9277

https://www.gbif.org/species/9304493

Philippine-endemic

Hungerford & Matsuda, 1961

1E1DDA0E-D94E-5B06-9911-DE84D176956A

Philippine-endemic

unpublished records as stated by Zettel (2014)

Zettel, 1994

C141445A-AC54-553C-BB61-D57F9768139D

https://www.gbif.org/species/9348222

Mindoro-endemic

Zettel, 1996

A15A0092-345A-5551-ABEC-EF280F783285

https://www.gbif.org/species/9281967

Mindoro-endemic

Zettel, 1994

1CBF62AB-4A24-5CFC-A370-65CF9A237E25

https://www.gbif.org/species/9396752

Mindoro-endemic

Breddin, 1905

0F643250-6B3D-5D1E-AB58-5BE524F12A01

https://www.gbif.org/species/5866044

Zettel & Ruiz, 2003

975D94D4-1543-58D5-A96D-B47CE4C0B162

https://www.gbif.org/species/9739670

Philippine-endemic

Andersen, 1975

F2D937F4-96D3-58CA-8D07-70072ADB823D

https://www.gbif.org/species/4773682

(Mayr, 1865)

10D0A1D3-153A-5EA4-9EC1-C39CC388F6A7

https://www.gbif.org/species/8114430

Mayr, 1865

E4D41825-00DE-5BD7-B28B-684FBECF084F

https://www.gbif.org/species/9688002

Mayr, 1865

341C17B2-2341-59EB-89A8-C2475E7A31F5

https://www.gbif.org/species/9731155

Philippine-endemic

Hungerford & Matsuda, 1958

AF96C455-03F9-5058-9AE3-9F399D7F4A16

https://www.gbif.org/species/9790486

Mindoro-endemic

Stål, 1853

FE873AB9-FFB9-5154-BAC5-B0FBE21C5280

(Kirkaldy, 1909)

CA7FEF25-B26C-5297-B998-6CE52BAB279F

https://www.gbif.org/species/9684453

Philippine-endemic

Herring, 1961

FE8E4707-152A-5E94-A81C-EB92A0C7B96A

https://www.gbif.org/species/6453976

Schadow, 1922

A0F79B98-43DC-54E5-86B1-3D1A3943D62E

https://www.gbif.org/species/6453984

Esaki, 1926

1A031821-6BF2-5872-8C52-426995B920B6

https://www.gbif.org/species/9764735

Discussion

Fifty-one species of and are known from Mindoro, of which 29 were documented in this study. Four of them were new records to the Island, namely , , and . Some of the remaining species/subspecies are common and widespread in the Philippines and neighbouring areas, while nine are endemic to Mindoro (see checklists above). In addition, at least three species are likely to be new to science, although we refrain from a formal description here.

As generally observed in the Philippines and adjacent areas, (riffle bugs) and (true water striders) are the most speciose families. With the two new records of , are also surprisingly diverse.

The biogeographic history of the Island is partly reflected by the species assemblages, especially in terms of a good number of island-endemic species. Unlike many other Philippine Islands of marine origin, Mindoro belongs to the so-called Palawan Microcontinental Block, a fragment of the Eurasian continental margin (Hall 2002). This is, however, not notably reflected in the current species composition of water bugs, since more recent dispersal and species radiation mechanisms might have had more impact on the current species distribution. Amongst the taxa treated here, only Esaki, 1926 (see Esaki 1926) has a distinct Palawan-Mindoro distribution range in the Philippines (although it is widely distributed in southeast Asia). An unusual pattern is observed for some closely-related species/subspecies of the Lundblad, 1936 (see Lundblad 1936) group, of which two different subspecies of (Matsumura, 1913) (see Matsumura 1913) are distributed in either Borneo and Palawan or Taiwan and Luzon, respectively, but missing on Mindoro Island, where it is replaced by the closely-related (Zettel et al. 2020).

Despite their close vicinity to Luzon, the Islands remained always disconnected during the Quaternary (Hall 2002). Nevertheless, Mindoro and the eastern Philippine Islands share a large proportion of water bugs.

Amongst the species of the checklist that were unambiguously identified, 20% are endemic to Mindoro, another 28% Philippine-endemic, making almost half of all species endemic to the country. The island-endemism rate is slightly lower than in Palawan, with one-third endemism amongst aquatic and semi-aquatic bugs (Freitag and Zettel 2012). This is likely due to the closer vicinity of Mindoro to other intra-Philippine biogeographic regions - notably Luzon - enabling easier dispersal across sea barriers.

In this study, special emphasis was given to the collection in lotic systems, which might have led to an under-representation of typical pond- and lake-dwelling species. Nevertheless, stream-associated lentic microhabitats, such as side pools and residual pools, were sampled in most collecting sites. Representatives of the genera , , , , and are typically found there, but also (which is usually a pond or lake dweller) (Freitag and Pangantihon 2010, current study).

Worth noting is that hygropetric microhabitats are an important habitat for several, partly rare and endemic species, foremost of these being , , and spp. Such habitas are particularly threatened by deforestation and land-use changes since they are prone to drying up when not continuously fed with water from the forested areas or when they are fully exposed to direct sunlight.

Fast flowing or even torrent waters, on the other hand, are typically inhabited by species of , and , as well as amongst the taxa treated here.

A few nepomorphan taxa are particularly attracted to light. sp. and were only retrieved by black light traps in this study. Emergence traps rarely yield aquatic and riparian . We caught only very few specimens of and sp. in such traps.