New records of bee flies (Diptera, Bombyliidae) from Cuatro Ciénegas, Coahuila, Mexico.

Forty one new records of species of Bombyliidae are reported for Coahuila in northeastern Mexico. Nine of these species are reported for the first time for the country. The specimens were collected in the Cuatro Ciénegas Basin and Sierra La Madera mountains during 2007-2013. The modified distributions of species are discussed. The gaps in the distribution of many species suggest an undersampling of this group of insects in the north of Mexico.

Introduction

The bee flies (Bombyliidae) belong to the superfamily Asiloidea and are the eighth most diverse family within Diptera with 5382 described species (Pape et al. 2011). All species of Bombyliidae are parasitoids, hyperparasitoids or predators of immature stages of Coleoptera, Hymenoptera, Lepidoptera, Orthoptera, Neuroptera, and PageBreakDiptera (Yeates and Greathead 1997, Boesi et al. 2009). Unlike most other taxa, bee flies are most abundant and diverse in arid and semiarid portions of the world (Hull 1973, Evenhuis 1989). In the immature stages these insects function as a natural control for populations of other insects and as adults are efficient pollinators (Motten et al. 1981, Kearns 2001).

Some faunistic studies have been completed including Bombyliidae in Mexico (Rodríguez-Ortuño 1989, Ávalos-Hernández 2007), but the northern region of the country is poorly known for this family. Although Evenhuis and Greathead (1999) list 15 species of Bombyliidae for Coahuila, species richness in this state is probably higher as suggested by the richness of surrounding Mexican states with similar or even smaller size and similar ecosystems (e.g., Nuevo León, 37 species; Durango, 41 species) and of Texas (171 species), the nearest USA state.

Cuatro Ciénegas Basin in the northeast of Coahuila is especially interesting because of its geological history and the presence of water ponds and gypsum dunes, which create a different environment from the surrounding areas. The basin was a shallow sea from the Pangea breakup until the Eocene, 40 Ma, when the Sierra Madre Oriental in the east of Mexico rose isolating the Basin from the Atlantic Ocean (Souza et al. 2012). The physiology of Cuatro Ciénegas bacteria is similar to that of marine species, with which they are closely related (Souza et al. 2006). According to Moreno-Letelier et al. (2012) this evidence indicates that some water was kept trapped in the Basin when the ocean retreated giving the basin unique characteristics. These characteristics produced a high number endemism for vertebrates and prokaryotes in Cuatro Ciénegas (Souza et al. 2006, 2012).

The present study is the first known long-term systematic sampling of Diptera in Cuatro Ciénegas. The objective of this project is to complete the list of species of Bombyliidae in the basin and surrounding mountains. In this paper, 41 new species-level records for Coahuila from Cuatro Ciénegas are presented, including nine new records for Mexico. The modified distributions of the species are discussed.

Methods

Beeflies were collected at nine sites from Cuatro Ciénegas Basin and Sierra La Madera within the Municipality of Cuatrociénegas (Figure 1). Abbreviations for study sites (Table 1) are used throughout. Samplings were performed during 2007-2013, using aerial net and a Malaise trap. The Malaise trap had white polyester netting, was square in configuration, 210 cm tall and 120 cm wide and the collecting head located at the top. Trap was set from 9:00 to 17:00 when weather conditions allowed it. To avoid damage to the specimens no killing agent was used, insects were extracted at the end of the day. Specimens were pinned and labeled. Generic identification was carried out under a stereomicroscope according to the keys by Hall (1981b) and Kits et al. (2008). Species were identified by the first and second authors with specialized keys for each genus and comparison with museum specimens, keys used for identification of each PageBreakgenera are specified below. Taxonomic classification and distribution data are based on Evenhuis and Greathead (1999) and host data are based on Hull (1973), if not indicated otherwise. Distribution gaps are suggested as disjunct distribution patterns or the result of under sampling by comparing the location of records in Mexico with those in the southern states of the USA. All specimens are deposited in the Colección Nacional de Insectos (Instituto de Biología, Universidad Nacional Autónoma de México; CNIN-IBUNAM).

Figure 1.

Field work sites. Cuatro Ciénegas basin is located in Coahuila at northeast of Mexico. Sierra La Madera is located at northwest of the basin.

Table 1.

Field work sites in Cuatro Ciénegas. Vegetation according to Pinkava (1979).

	Site (Code)	Location	Altitude (m)	Vegetation
1	Churince (CHU)	26°50'30"N, 102°08'10"W	770	Gypsum dunes; sedges and marshes; mezquital, halophile
2	Rancho Orozco (ROR)	26°52'18"N, 102°05'17"W	740	Sedges and marshes; mezquital; halophile
3	Rancho Pozas Azules (RPA)	26°49'39"N, 102°01'24"W	710	Sedges and marshes; mezquital; halophile
4	Ejido Antiguos Mineros (EAM)	26°46'58"N, 102°00'20"W	725	Sedges and marshes; mezquital; halophile
5	El Cañón (ECA)	27°00'34"N, 102°04'42"W	780	Mezquital; desert scrub
6	Ejido El Oso (EEO)	27°03'08"N, 102°13'35"W	1085	Desert scrub; chaparral
7	Rancho El Espejo (REE)	27°13'19"N, 102°30'19"W	1425	Desert scrub; chaparral
8	Rancho El Chupadero (REC)	27°10'07"N, 102°34'26"W	1790	Desert scrub; chaparral; Pine-Oak forest
9	Rancho La Casita (RLC)	27°06'45"N, 102°23'40"W	1630	Desert scrub; chaparral; Pine-Oak forest

Results

A total of 41 new species-level records are presented for the state of Coahuila. Nine of these 41 species are recorded for the first time in Mexico, being their most southern records. Of the 15 species previously listed for Coahuila, two were collected during this study: (Osten Sacken, 1877) (Material collected: CHU: Apr (1 M), Sep (1 M); EAM: Mar (2 M), Sep (1 F), Jun (2 F), Jul (1 F), Oct (1 F); ROR: Apr (1 F, 3 M), May (1 F, 2 M), Jul (3 F), Sep (1 F); RPA: Apr (1 F, 1 M), Jul (2 F, 2 M), Sep (1 M), Oct (2 M)); and Tucker, 1907 (Material collected: EAM: Oct (1 M); ECA: Oct (1 F, 1M); ROR: Oct (7 F, 6 M); RPA: Sep (1 M)).

New records of the species included in this paper are from 17 genera for which modern revisions are available. Six taxa of (3), (1), (1) and (1) could not be identified accurately, being probably undescribed species. Identification of species in another 10 genera found in the study (e.g. , , and ) is difficult and unreliable. The number of morphospecies and specimens collected of these genera are presented in Table 2. Six species of (1), (1), (3) and (1) previously listed for Coahuila were probably collected but specimens of these genera are still being identified. Taxonomic work will continue, updates of the species list and descriptions of the new taxa will be published in subsequent papers.

Table 2.

Updated list of genera and species of Bombyliidae in Coahuila (* species not collected in this study, but recorded previously in Coahuila; ** species most likely collected in this study, but identification not yet certain).

Subfamily, genus and species name	New record	Unidentifiable material
PHTHRIINAE
Neacreotrichus Cockerell
* Neacreotrichus consors (Osten Sacken, 1887)
Poecilognathus Jaennicke	Coahuila	1 morphospecies, 3 specimens
Relictiphthiria Evenhuis
* Relictiphthiria psi (Cresson, 1919)
Tmemophlebia Evenhuis		1 morphospecies, 21 specimens
** Tmemophlebia coquilletti (Johnson, 1902)
TOXOPHORINAE
Geron Meigen		2 morphospecies, 194 specimens
** Geron holosericeus Walker, 1849
Systropus Wiedemann	Coahuila	1 morphospecies, 5 specimens
Toxophora Meigen	Coahuila
Toxophora maxima Coquillett, 1886	Coahuila
Toxophora virgata Osten Sacken, 1877	Coahuila
BOMBYLIINAE
Anastoechus Osten Sacken
Anastoechus melanohalteralis Tucker, 1907
Bombylius Linnaeus
Bombylius (Bombylius) frommerorum Hall & Evenhuis, 1980	Coahuila
* Bombylius (Bombylius) sylphae Evenhuis, 1984
* Bombylius (Parabombylius) aleophilus (Hall & Evenhuis, 1981)
* Bombylius (Parabombylius) coahuilensis (Hall & Evenhuis, 1981)
* Bombylius (Parabombylius) paradoxus (Hall & Evenhuis, 1981)
* Bombylius (Parabombylius) syndesmus (Coquillett, 1894)
Conophorus Meigen	Coahuila	1 morphospecies, 3 specimens
Heterostylum Macquart
Heterostylum croceum Painter, 1930	Mexico
Heterostylum robustum (Osten Sacken, 1877)
Lordotus Loew	Coahuila	1 morphospecies, 38 specimens
Lordotus diplasus Hall, 1954	Coahuila
Lordotus divisus Cresson, 1919	Coahuila
Lordotus perplexus Johnson & Johnson, 1959	Coahuila
Triploechus Edwards	Coahuila
Triploechus novus (Williston, 1893)	Coahuila
LOMATIINAE
Ogcodocera Macquart	Coahuila
Ogcodocera analis Williston, 1901	Coahuila
TOMOMYZINAE
Paracosmus Osten Sacken	Coahuila
Paracosmus (Paracosmus) morrisoni Osten Sacken, 1887	Coahuila
ANTHRACINAE
Anthrax Scopoli	Coahuila
Anthrax atriplex Marston, 1970	Coahuila
Anthrax cybele (Coquillett, 1894)	Mexico
Anthrax georgicus Macquart, 1834	Coahuila
Anthrax irroratus Say, 1823	Coahuila
Anthrax oedipus Fabricius, 1805	Coahuila
Anthrax pauper (Loew, 1869)	Mexico
Anthrax seriepunctatus (Osten Sacken, 1886b)	Coahuila
Aphoebantus Loew	Coahuila	4 morphospecies, 236 specimens
Chrysanthrax Osten Sacken	Coahuila	6 morphospecies, 240 specimens
Dipalta Osten Sacken	Coahuila
Dipalta serpentina (Osten Sacken, 1877)	Coahuila
Exoprosopa Macquart		9 morphospecies, 395 specimens
** Exoprosopa aztec Painter & Painter, 1969
** Exoprosopa butleri Johnson & Johnson, 1958
** Exoprosopa dorcadion Osten Sacken, 1877
Hemipenthes Loew	Coahuila	3 morphospecies, 146 specimens
Hemipenthes jaennickeana (Osten Sacken, 1886a)	Coahuila
Hemipenthes lepidota (Osten Sacken, 1886b)	Coahuila
Hemipenthes scylla (Osten Sacken, 1887)	Coahuila
Hemipenthes sinuosa (Wiedemann, 1821)	Coahuila
Lepidanthrax Osten Sacken	Coahuila
Lepidanthrax arizonensis Hall, 1976	Mexico
Lepidanthrax disiunctus (Wiedemann, 1830)	Coahuila
Lepidanthrax hesperus Hall, 1976	Coahuila
Lepidanthrax hyposcelus Hall, 1976	Coahuila
Lepidanthrax proboscideus (Loew, 1869)	Coahuila
Ligyra Newman	Coahuila	1 morphospecies, 2 specimens
Neodiplocampta Curran	Coahuila
Neodiplocampta (Neodiplocampta) miranda Hull & Martin, 1974	Coahuila
Paravilla Painter	Coahuila	1 morphospecies, 48 specimens
Paravilla edititoides (Painter, 1933)	Coahuila
Paravilla flavipilosa (Cole, 1923)	Coahuila
Paravilla parvula Hall, 1981a	Coahuila
Paravilla separata (Walker, 1852)	Mexico
Poecilanthrax Osten Sacken	Coahuila
Poecilanthrax effrenus (Coquillett, 1887)	Coahuila
Poecilanthrax fasciatus Johnson & Johnson, 1957	Mexico
Poecilanthrax hyalinipennis Painter & Hall, 1960	Mexico
Poecilanthrax poecilogaster (Osten Sacken, 1886b)	Coahuila
Rhynchanthrax Painter	Coahuila	1 morphospecies, 70 specimens
Rhynchanthrax capreus (Coquillett, 1887)	Mexico
Rhynachantrax texanus (Painter, 1933)	Coahuila
Thyridanthrax Osten Sacken	Coahuila
Thyridanthrax pallidus (Coquillett, 1887)	Mexico
Thyridanthrax selene (Osten Sacken, 1886b)	Coahuila
Villa Lioy		9 morphospecies, 115 specimens
** Villa fumicosta Painter & Painter, 1962
Xenox Evenhuis	Coahuila
Xenox xylocopae (Marston, 1970)	Coahuila

A total of 28 genera were found during this study, of which 21 are new records for the state. Two genera previously listed for Coahuila ( and ) were not found in Cuatro Ciénegas area. With the new records presented here, the list of bee fly species in Coahuila increases to 56 (Table 2).

Subfamily Toxophorinae

Meigen

Remarks.

is distributed worldwide, being more diverse in the Afrotropical and Palearctic regions. Mexico's fauna includes three Neotropical species and five Nearctic species. All Nearctic species of Mexico were distributed in the western half of the country. These two new records represent the first of this genus in Coahuila and the most eastern distribution of the Nearctic species in the country. The New World species of this genus were keyed using Cunha et al. (2011).

Coquillett, 1886

Figure 2a, b

Figure 2.

. , male (CNIN 1115) a dorsal view b lateral view; , male (CNIN 1109) c lateral view d posterior view. All scale bars: 3 mm.

Material examined.

CHU: Jul (1 M); EEO: Jul (2 F, 2 M), Oct (1 F, 3 M).

Known Nearctic records.

Mexico (Baja California, Baja California Sur, Coahuila); USA (Arizona, California, Idaho, Kansas, New Mexico, Oklahoma, Oregon, Texas).

Comments.

In Mexico was only known from Baja California Peninsula and now Coahuila. This apparent gap in its distribution is probably due to undersampling. Sampling of the intermediate zones is necessary to know if these populations form a continuous unit as they do in the southern states of USA.

Osten Sacken, 1877

Figure 2c, d

EAM: Jun (1 F, 1 M), Jul (1 F); CHU: Aug (1 M), Oct (1 M); EEO: Jul (1 M), Oct (1 F, 1 M); RLC: Jun (1 M); ROR: Apr (1 F, 2 M); RPA: Oct (1 F).

Mexico (Baja California Sur, Coahuila, Sonora); USA (Arizona, California, Colorado, Georgia, Idaho, Nevada, New Mexico, Oklahoma, Texas, Utah).

Known hosts.

sp. (Vespidae); Saussure (Vespidae).

This species is present in the all southwestern states of the USA and northwest of Mexico. This is the first record in the northeast of Mexico. The species is probably also present in Chihuahua, between Sonora and Coahuila.

Subfamily Bombyliinae

Linnaeus

With 278 described species, is the second most diverse genus of Bombyliidae. It has a worldwide distribution being especially diverse in the Palearctic and Nearctic regions. One endemic species is present in Coahuila: (Hall & Evenhuis, 1981). Four other species are reported for the state: Evenhuis, 1984, (Hall & Evenhuis, 1981), (Hall & Evenhuis, 1981), (Coquillett, 1894). A review with identification keys for Nearctic species is presented in Hall and Evenhuis (1980), later Evenhuis (1984) revised and present keys for the comanche group of America.

Hall & Evenhuis, 1980

Figure 3

Figure 3.

, female (CNIN 772) a dorsal view b lateral view. All scale bars: 3 mm.

EEO: Aug (1 M), Oct (1 F).

Mexico (Chihuahua, Coahuila); USA (Arizona, New Mexico, Texas).

This species is restricted to the southwest of the USA and north of Mexico.

Macquart

The genus is only present in Nearctic and Neotropical regions. Although not as diverse as other genera (only 12 species), specimens from some species are abunPageBreakdant in the field. was previously known from Coahuila and was collected during this study. This species is distributed from Canada to central Mexico. There are two revisions for this genus that contains identification keys, one by Hall and Evenhuis (1980) and the more recent by Cunha et al. (2007).

Painter, 1930

Figure 4

Figure 4.

, female (CNIN 858) a dorsal view b lateral view. All scale bars: 3 mm.

REE: Apr (1 F).

Mexico (Coahuila); USA (Colorado, Kansas, Missouri, New Mexico, Texas).

is recorded for the first time in Mexico; previously known from the southern-central United States. Hall and Evenhuis (1980) suggest that may be related to Painter, 1930 or even be a subspecies of that taxon, is the eastern form and the western form (Arizona, California, Texas, Utah) although both species are present in Texas. Cunha et al. (2007) comment that can be distinguished by the presence of white to very pale yellow hair and brown-tipped hairs on the abdomen compared with the darker yellow hairs in .

Loew

Most of the 29 species in this exclusively Nearctic genus are distributed in the southwest of the USA and north of Mexico, although eight species are present in the northwest of the USA (PageBreak Coquillet, 1887; Painter, 1940; Coquillett, 1891; Loew, 1863; Coquillett, 1887; Williston, 1893; Painter, 1940; Coquillett, 1887). The three species present in Coahuila are also found in California; their distribution probably includes all northern states of Mexico. Hall (1954) and Hall and Evenhuis (1982) present reviews of the genus and keys to the species.

Hall, 1954

Figure 5a, b

Figure 5.

. , a female (CNIN 774) dorsal view b male (CNIN 861) dorsal view c , male (CNIN 777) dorsal view; , female (CNIN 801) d dorsal view e lateral view. All scale bars: 3 mm.

CHU: Sep (2 M); RLC: Sep (2 M); RPA: Sep (1 F).

Mexico (Coahuila, Zacatecas); USA (Arizona, California, New Mexico).

Cresson, 1919

Figure 5c

ECA: Mar (1 M), Apr (2 M); EEO: Apr (16 M); REE: Apr (4 M); ROR: Apr (1 M).

Mexico (Coahuila, Baja California); USA (Arizona, California, Nevada, New Mexico, Texas).

Johnson & Johnson, 1959

Figure 5d, e

CHU: Apr (1 H), ECA: Apr (1 H); EEO: Apr (4 F); REE: Apr (7 F); ROR: Apr (1 F).

Mexico (Baja California, Coahuila, Sinaloa, Sonora); USA (Arizona, California, Nevada, Texas).

has the most southern distribution in the genus, reaching Sinaloa on the Pacific coast.

Edwards

Four species of are present in Nearctic region: Hall, 1975; (Williston, 1893); (Bigot, 1892); Hall, 1975. Of these is endemic to Mexico and has the widest distribution of this genus, being present in the south of the USA and center of Mexico. Hall and Evenhuis (1981) present a revision and key for species for this genus.

(Williston, 1893)

Figure 6

Figure 6.

, female (CNIN 1237) dorsal view. Scale bar: 3 mm.

CHU: Apr (7 F, 6 M); REE: Apr (1 M); RPA: Apr (1 M).

Mexico (Coahuila, Durango, San Luis Potosí, Sonora); USA (Arizona, California, Nevada, New Mexico, Texas).

This is a widespread and apparently common species. All specimens were collected in April so it may have a short flight season.

Subfamily Lomatiinae

Macquart

The only two species in this genus have been collected from the neotropical part of Mexico to north of the USA and Canada. (Wiedemann, 1828), not sampled during this study, is present in the whole Nearctic region from Canada to south of Mexico.

Williston, 1901

Figure 7

Figure 7.

, male (CNIN 146) dorsal view. Scale bar: 3 mm.

EEO: Aug (2 M), Oct (1 M).

Mexico (Coahuila, Guerrero, Morelos); USA (Arizona, Texas).

This record is the first of this species in the north of Mexico, but it has been previously collected in the south of Mexico and in the south of USA, and thus is probably distributed across the whole country. Unlike , has its most northern distribution in Arizona and Texas.

Subfamily Tomomyzinae

Osten Sacken

All five extant species of have Nearctic distributions, and all are present in California. Two of these species have been collected in the northwest of Mexico ( Melander, 1950 and Osten Sacken, 1887).

Osten Sacken, 1887

Figure 8

Figure 8.

, male (CNIN 832) a dorsal view b lateral view. All scale bars: 3 mm.

EAM: Apr (1 F, 1 M); CHU: Apr (2 M), Jul (1 F), Aug (2 F); ECA: Apr (1 M); EEO: May (1 F); REE: Apr (1 F); ROR: Apr (2 M), May (1 F, 3 M); RPA: Apr (1 F).

Mexico (Coahuila, Sonora); USA (Arizona, California, Nevada, Texas).

has the widest distribution within this genus, but in Mexico had previously only been recorded in Sonora. This record represent the most eastern distribution for the genus in the country.

Subfamily Anthracinae

Scopoli

This is a diverse genus with 248 species worldwide. Two old but complete revisions of the genus, including distribution maps and keys, were made by Marston (1963, 1970). Thanks to these species can be easily identified. Some species are widely distributed occupying two biogeographic regions. From the seven species collected in this study in Coahuila, just (Coquillett, 1894) has a restricted distribution. The other six species are widespread across the Nearctic region. Two species of are reported for the first time for Mexico.

Marston, 1970

Figure 9a

Figure 9.

part I. a , male (CNIN 1098) dorsal view b , male (CNIN 1087) dorsal view c , female (CNIN 1071) dorsal view d , male (CNIN 1027) dorsal view. All scale bars: 3 mm.

EAM Apr (1 F); ROR: Oct (2 M); RPA: Aug (1 M); Sep (1 M); Oct (1 F, 2 M).

Mexico (Baja California Sur, Coahuila, Durango, Sonora, Tamaulipas); USA (Arizona, California, New Mexico, Oregon, Texas, Utah).

Known host.

Cresson (Megachilidae).

This species may be present in all the north of Mexico, including Chihuahua, Nuevo León and possibly Sinaloa.

(Coquillett, 1894)

Figure 9b

ECA: Apr (2 F); EEO: Apr (1 M).

Mexico (Coahuila); USA (Arizona, California).

This is a rare species flying in April. Its distribution is disjunct so far, present in the southwest of the USA and northeast of Mexico. It is probably also found in New Mexico and Texas in the USA and Sonora and Chihuahua in Mexico.

Macquart, 1834

Figure 9c

EAM: Mar (1 F), Apr (1 M), Jun (1 F, 2 M), Jul (2 F), Sep (2 M); ROR: Apr (1 F), Sep (1 M); RPA: Mar (1 M), Apr (1 F, 1 M), Jul (2 F, 1 M), Sep (6 F, 3 M), Oct (6 F, 3 M).

Canada (Alberta, British Columbia, Manitoba, Northwest Territory, Ontario, Quebec, Saskatchewan); Mexico (Coahuila, Guerrero, Michoacán de Ocampo, Morelos, Nuevo León, Puebla, Sonora, Veracruz); USA (Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Idaho, Illinois, Iowa, Kansas, Kentucky, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming).

The range of includes all North America and Central America (Nicaragua, Costa Rica) covering a wide diversity of habitats and environmental conditions. Common in the rainy season and present in the dry season (March), this species is probably present in most if not all states of Mexico, but has only been collected in eight of them.

Say, 1823

Figure 9d

EAM: Apr (1 M), Aug (2 M), Oct (1 M); ECA: Apr (1 F), May (1 F, 1 M); EEO: Apr (2 F), Jul (4 F), Aug (1 M); REC: Apr (3 F, 10 M), Aug (1 M); REE: Aug (1 M); RLC: Jul (6 F, 10 M); ROR: Feb (1 M), Aug (5 M), Sep (1 M); RPA: Apr (1 M), Aug (2 M).

Canada (Alberta, British Columbia, Manitoba, Northwest Territory, Nova Scotia, Ontario, Quebec, Saskatchewan); Mexico (Baja California, Baja California Sur, Coahuila, Colima, Guerrero, Michoacán, Morelos, Nayarit, Puebla, San Luis Potosí, Sinaloa, Sonora, Veracruz, Zacatecas); USA (Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Idaho, Illinois, Indiana, Kansas, Maryland, Massachusetts, Michigan, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Tennessee, Texas, Utah, Virginia, West Virginia, Wyoming).

Cresson (Megachilidae); Cresson (Megachilidae); Timberlake (Megachilidae); Cresson (Megachilidae); Cockrell and Casad (Colletidae). Scott and Strickler (1992) also reared from Cresson (Megachilidae) and Provancher (Megachilidae).

, like (above), is present in all of North America and reaches Central America and Caribbean islands (Honduras, Puerto Rico). More abundant than its congener, this species has been collected in 15 states in Mexico (including Oaxaca of the Neotropical region not listed above) and all regions of the USA. should be collected in any systematic, long term Bombyliidae sample in Mexico and the USA.

Fabricius, 1805

Figure 10a

Figure 10.

part II. a , female (CNIN 1055) dorsal view b , female (CNIN 1085) dorsal view c , female (CNIN 1089) dorsal view. All scale bars: 3 mm.

ECA: Apr (1 F, 1 M), Jul (1 F); EEO: Apr (2 F, 1 M), May (1 F, 4 M), Jul (1 M); REC: Apr (1 F); REE: Apr (2 M); RLC: Jul (2 F, 4 M), Sep (1 F); RPA: Apr (1 M), Aug (1 M).

Mexico (Baja California, Coahuila, Nayarit, Morelos, Sinaloa, Sonora); USA (Nevada, Texas).

Apparently closely related to , has a narrow distribution in the Nearctic region but is widely distributed in all South America. In the USA it has been collected only in two southern states, while it occurs in most of the northern states of Mexico and one central state (Morelos); it may be present in most areas from Texas to Argentina.

(Loew, 1869)

Figure 10b

CHU: Apr (1 F, 1 M).

Canada (Ontario); Mexico (Coahuila); USA (Alabama, Colorado, Illinois, Indiana, Kansas, Maryland, Massachusetts, Michigan, Nebraska, New Jersey, New Mexico, New York, Oklahoma, Pennsylvania, Texas, Utah, Vermont, Virginia, Wisconsin).

With just two specimens collected, appears to be a rare species in this region. This population is the most southern recorded of this species, mostly present in the center and east of the USA. Presumably adapted to colder climates, it is no coincidence that it was collected in the most elevated site sampled.

(Osten Sacken, 1886b)

Figure 10c

EAM: Jun (1 M); CHU: Apr (1 F), Aug (1 F), Sep (1 F); ECA: Jun (1 M); REE: Aug (1 F); RLC: Jun (1 F), Jul (1 F, 2 M).

Mexico (Baja California Sur, Coahuila, Sonora, Puebla); USA (Arizona, Nevada, New Mexico, Texas).

This species is recorded mostly from the south of the USA and north of Mexico, but its presence in Puebla in central Mexico suggests a wider distribution within the country, at least in all northern states.

Osten Sacken

is a small genus with just two species. Johnson, 1921 is only present in eastern Canada and USA, while is distributed from Central America to the northern USA.

(Osten Sacken, 1877)

Figure 11

Figure 11.

, male (CNIN 215) dorsal view. Scale bar: 3 mm.

REC: Aug (1 M); RLC: Jul (1 M).

Mexico (Coahuila, Guerrero, Hidalgo, México, Morelos, Puebla, San Luis Potosí, Sinaloa); USA (Arizona, Arkansas, California, Colorado, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Mexico, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, South Dakota, Tennessee, Texas, Utah, Washington, Wisconsin, Wyoming).

De Geer (Myrmeleontidae).

This species is probably present in all of Mexico, but this is the only record in the north of Mexico.

Loew

is equally diverse in the Nearctic (29 species), Neotropical (26 species) and Palearctic (37 species) regions, with just six species in the Oriental region and one in the Afrotropical region. Four species of this genus were collected in Coahuila. All of these have broad distributions but apparently from poor sampling because records are not continuous, especially in Mexico. Ávalos-Hernández (2009) recently published a revision of , with a key for Nearctic species.

(Osten Sacken, 1886a)

Figure 12a

Figure 12.

. a , female (CNIN 1137) dorsal view b , female (CNIN 200) dorsal view c , male (CNIN 725) dorsal view d , female (CNIN 1134) dorsal view. All scale bars: 3 mm.

REC: Apr (18 F), Aug (4 F); REE: Feb (3 F); RLC: Mar (7 F), Jul (23 F, 3 M), Sep (3 F).

Mexico (Coahuila, Morelos, Sonora); USA (Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Texas, Utah).

Present mainly in the Pacific coast states of the USA and Mexico, from Oregon as far as Morelos in the center of Mexico. This record is the most eastern record in Mexico.

(Osten Sacken, 1886b)

Figure 12b

EAM: Apr (1 M), Aug (1 F); CHU: Apr (1 F, 3 M), Aug (1 M); EEO: Jul (1 F, 4 M), Aug (1 F); REC: (1 M); REE: Apr (11 F, 2 M), Aug (1 F); RLC: Jun (1 F), Jul (3 F); RPA: Apr (1 F), Sep (4 F), Oct (2 F).

Canada (Alberta); Mexico (Baja California, Baja California Sur, Coahuila, Chihuahua, Guerrero, Morelos, Puebla, San Luis Potosí, Sonora, Tamaulipas); USA (Arizona, California, Colorado, Idaho, Louisiana, Nevada).

This species is abundant in the rainy season in most of the Nearctic region but has not been collected in many states of Mexico or the USA where it probably is present.

(Osten Sacken, 1887)

Figure 12c

REC: Apr (23 M), Aug (7 M); REE: Feb (5 M), Apr (2 M); RLC: Mar (8 M), Jul (8 M), Sep (9 M).

Mexico (Coahuila, Morelos, Guanajuato, Sonora); USA (Arizona, Texas).

Males of this species are abundant all year long but females are unknown. There is no explanation for this lack of females in the collections. Extreme sexual dimorphism and misidentification of females can be dismiss, since there is no species from which only females are known. One possible explanation is that females life span is too short and therefor encounter probabilities are low. Distribution is discontinuous with populations present in central and northern Mexico and the southern USA; it is unknown whether this species is present in between these areas.

(Wiedemann, 1821)

Figure 12d

REC: Apr (3 F); REE: (Feb (1 F), Apr (2 F); RLC: Jul (1 F, 1 M), Sep (1 M); RPA: Sep (2 F).

Mexico (Coahuila, Morelos); USA (Alabama, Arizona, Arkansas, Connecticut, Delaware, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Minnesota, Mississippi, Missouri, Nebraska, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Vermont, Virginia, West Virginia, Wisconsin).

Geoff. (Diprionidae).

is only known from Morelos in the center of Mexico and Coahuila in the northeast, but can be found almost in all of the USA. It is clearly undersampled in Mexico.

Osten Sacken

Forty seven of the 52 species of are from the Nearctic region. Hall (1976) published a revision of this genus including keys for species.

Hall, 1976

Figure 13a

Figure 13.

. a , female (CNIN 1352) dorsal view b female (CNIN 334) dorsal view c , male (CNIN 1339) dorsal view d , male (CNIN 369) dorsal view e , male (CNIN 357) dorsal view. All scale bars: 3 mm.

EEO: Mar (1 F); Oct (2 M).

Mexico (Coahuila); USA (Arizona).

has a restricted distribution, being present only in Arizona and Coahuila, but probably is also present in Chihuahua, Texas and New Mexico.

(Wiedemann, 1830)

Figure 13b

REC: Aug (2 F, 1 M).

Mexico (Coahuila, Distrito Federal, Guerrero, Veracruz); USA (Arizona).

The distribution of has its northern extreme in Arizona and its southern extreme in Oaxaca, in the southeast of Mexico. It seems this species is rarely collected, but widely distributed.

Hall, 1976

Figure 13c

EAM: Apr (2 M); CHU: Apr (2 F, 5 M); ROR: Apr (1 F, 3 M), May (1 F, 1 M); RPA: Apr (1 F, 14 M).

Mexico (Baja California, Coahuila, Sinaloa, Sonora); USA (Arizona, California, New Mexico, Texas).

This record is the first in northeastern Mexico.

Hall, 1976

Figure 13d

RLC: Sep (4 F, 15 M).

Mexico (Coahuila, Guerrero, Morelos, Puebla).

is endemic to Mexico, previously only known from the southwest of the country; this record extends its distribution to the northeast of the country.

(Loew, 1869)

Figure 13e

ECA: Sep (1 F, 2 M); EEO: Apr (1 F), Aug (1 F, 1 M), Oct (4 F, 15 M); ROR: Sep (2 M); RPA: Sep (2 M), Oct (1 M).

Mexico (Baja California, Baja California Sur, Coahuila, Durango, Guerrero, Morelos, Sonora); USA (Arizona, California, Nevada, New Mexico, Utah).

, Hall, 1976 and are the only species of this genus distributed in both the Nearctic and Neotropical regions. Of these extends as far as El Salvador, the most southern distribution for a Nearctic species of this genus. This is the first record of this species in the northeast of Mexico.

Curran

is a small American genus, more diverse in the Neotropical than the Nearctic region. Hull and Martin (1974) described seven of the 16 species and published a key for all species of the genus.

Hull & Martin, 1974

Figure 14

Figure 14.

, female (CNIN 225) dorsal view. Scale bar: 3 mm.

CHU: Aug (1 F); EEO: Aug (1 F, 1 M); ROR: Jul (1 F); Oct (1 M); RPA: Aug (1 F, 2 M).

Mexico (Coahuila, Guerrero, San Luis Potosi, Sinaloa, Sonora); USA (Arizona, California, Florida, Texas).

and Hull, 1966 are the only two species distributed in both biogeographic regions (Nearctic and Neotropical). This species is distributed from the south of the USA to Nicaragua, but has not been collected in most Mexican states. This lack of records is possibly due its low abundance.

Painter

Fifty five of the 58 species of the genus are Nearctic. All species of collected in Coahuila were exclusively collected in the summer months from April to July. Hall (1981a) reviewed this genus and presented a key for species and description of new species.

(Painter, 1933)

Figure 15a

Figure 15.

. a , male (CNIN 1272) dorsal view b , male (CNIN 1125) dorsal view c , female (CNIN 884) dorsal view d , female (CNIN 898) dorsal view. All scale bars: 3 mm.

EAM: Jun (1 M); CHU: Apr (1 F), Jul (2 F, 1 M); ECA: Apr (1 F, 1 M), Jul (1 M); EEO: Apr (1 F, 10 M), May (1 F, 2 M), Jul (9 M); REE: Apr (1 M); RLC: Jun (2 F, 5 M), Jul (1 F); ROR: Jul (1 F, 3 M); RPA: Oct (1 M).

Canada (Saskatchewan); Mexico (Chihuahua, Coahuila, Durango, Jalisco, México, Zacatecas); USA (Arizona, Colorado, Idaho, Kansas, Montana, Nebraska, New Mexico, Oklahoma, Utah, Texas, Wyoming).

This species is very abundant and present in most of North America, from Canada as far as Jalisco in central Mexico.

(Cole, 1923)

Figure 15b

CHU: Apr (1 M); Jul (1 M); ECA: Apr (1 M); EEO: Apr (7 M), May (11 M); ROR: Apr (2 M); RPA: Apr (1 M).

Mexico (Baja California Sur, Coahuila, Nuevo León); USA (Arizona, California, Colorado, Texas).

is abundant and restricted to the south of the USA and north of Mexico.

Hall, 1981a

Figure 15c

EAM: Apr (1 F); CHU: Apr (1 M); RPA: Apr (7 F, 13 M).

Mexico (Chihuahua, Coahuila, Durango, Guanajuato, Hidalgo, Jalisco, México, Michoacán, Nuevo León, San Luis Potosí, Sonora, Zacatecas), USA (Arizona, New Mexico, Texas, Utah).

is relatively well collected in northern and central Mexico. Its distribution also includes the south of the USA but no farther north than Utah.

(Walker, 1852)

Figure 15d

CHU: Apr (1 F); EEO: Apr (3 F); REE: Apr (5 F, 3 M); RPA: Apr (1 M).

Canada (Ontario, Manitoba); Mexico (Coahuila); USA (Alabama, Florida, Georgia, Iowa, Kansas, Michigan, Minnesota, Mississippi, Nebraska, Ohio, South Dakota, Wisconsin).

is present mainly in the eastern half of the USA, and southeastern Canada. This record in Coahuila represents the southern extreme of the distribution of this species, and is the first in Mexico. It may also be present in Tamaulipas and Nuevo León but doubtfully in the northwest of Mexico.

Osten Sacken

Four species from this mainly Nearctic genus are recorded in Coahuila for the first time. Painter and Hall (1960) published a review of with a key and images of the species.

(Coquillett, 1887)

Figure 16a

Figure 16.

. a , female (CNIN 1380) dorsal view b , male (CNIN 218) dorsal view c , female (CNIN 1365) dorsal view d , male (CNIN 1356) dorsal view. All scale bars: 3 mm.

EAM: Apr (1 F, 1 M), Jun (1 F, 1 M), Sep (1 F); CHU: Jun (1 F); ROR: May (10 F, 5 M), Jul (2 F, 3 M), Aug (1 M); RPA: Jun (4 F, 1 M), Jul (6 F, 6 M), Aug (1 F, 1 M), Sep (4 F), Oct (2 F, 1 M).

Mexico (Baja California Sur, Chihuahua, Coahuila, Sonora, Tamaulipas); USA (Arizona, California, New Mexico, Oklahoma, Texas).

This record fills a gap in distribution between northwest and northeast populations of Mexico. This species is probably present in Baja California and Nuevo León, but has not yet been recorded.

Johnson & Johnson, 1957

Figure 16b

EAM: Sep (1 M); CHU: Oct (1 M); ROR: Oct (1 M); RPA: Oct (1 M).

Mexico (Coahuila); USA (Colorado, Kansas, Texas).

Grote (Noctuidae).

is collected in Mexico for the first time, and this extends the southern limit of this species distribution.

Painter & Hall, 1960

Figure 16c

EAM: Mar (3 M), Oct (1 F); CHU: Oct (1 M); ROR: Oct (4 M); RPA: Sep (1 F), Oct (2 F, 6 M).

Mexico (Coahuila); USA (Arizona, California, Nevada, Utah).

This record extends the distribution of into the northwest of Mexico. Considering its distribution in the USA, this species may also be present in the northeast of Mexico.

(Osten Sacken, 1886b)

Figure 16d

REE: Apr (2 M).

Canada (Alberta, Manitoba, Ontario, Saskatchewan); Mexico (Coahuila, Morelos, Nuevo León, Sonora); USA (Arizona, California, Colorado, Idaho, Nevada, New Mexico, Oregon, Utah).

Most of the records in the USA and Mexico of this rarely collected but widespread species are from Pacific Coast states, although, there are records from Nuevo Leon and Coahuila in northeast Mexico.

Painter

Of the seven species of this exclusively Nearctic genus, six are present in Mexico, with (Williston, 1901) and (Williston, 1901) being endemic to this country. Only (Loew, 1869) has not been collected in Mexico, but it is distributed across the southern USA and may also occur in the north of Mexico.

(Coquillett, 1887)

Figure 17a

Figure 17.

. a , female (CNIN 940) dorsal view b , male (CNIN 263) dorsal view. All scale bars: 3 mm.

CHU: Apr (1 M), Aug (13 F, 6 M), Jul (12 F, 6 M), Sep (1 F, 3 M).

Mexico (Coahuila); USA (Arizona, California, Colorado, Nebraska, Nevada, New Mexico, Utah).

This is the first record of this species in Mexico. is the only species occurring in the northwest of the USA, while the other species in the genus are present mainly in the south and east of the country. This species may also be present in the northwest of Mexico (Baja California, Sonora, Chihuahua).

(Painter, 1933)

Figure 17b

EEO: May (1 M); RLC: Jun (1 F, 11 M), Jul (3 M).

Mexico (Coahuila, Sonora); USA (Kansas, New Mexico, Texas).

This is the most eastern record in Mexico for this species. In the USA it is distributed in the southern-center of the country, but in Mexico it has been collected in Sonora so it probably also occurs in Arizona.

Osten Sacken

has twice as many species in the Palearctic region as in the Nearctic and Neotropical regions combined. All 12 species in North America are present in the USA with five also in Mexico. These are the first records of this genus in Coahuila. The distribution of (Osten Sacken, 1886b) and (Coquillett, 1887) are very similar, being present in all of the southern USA and probably also in all of northern Mexico, although they have been only collected in Sonora and Coahuila to date. Both species are rare and were collected only in April.

(Coquillett, 1887)

Figure 18b

Figure 18.

. a , male (CNIN 182) dorsal view b , female (CNIN 1162) dorsal view. All scale bars: 3 mm.

REE: Apr (4 F, 1 M).

Mexico (Coahuila); USA (Arizona, California, Nevada, Texas, Utah).

This represents the first record of this species in Mexico.

(Osten Sacken, 1886b)

Figure 18a

EAM: Apr (1 M); REE: Apr (2 F, 2 M).

Mexico (Coahuila, Sonora); USA (Arizona, California, Texas).

This is the most eastern record in Mexico.

Evenhuis

Of the five species that constitute this genus, four are present in Mexico.

(Marston, 1970)

Figure 19

Figure 19.

, male (CNIN 1165) dorsal view. Scale bar: 3 mm.

ECA: Sep (1 M).

Mexico (Chihuahua, Coahuila, Sonora), USA (Arizona, New Mexico, Texas).

(Hurd) (Apidae) as reported by Minckley (1989).

appears to be restricted to the northeast of Mexico and south of the USA. Three of the other species also have restricted and separate distributions: Loew, 1869 is present in the northwest of Mexico and California; (Schaeffer, 1768) occurs from the northeast of Mexico (Veracruz and Tamaulipas without overlap with ) to South America; and (De Geer, 1776) is present in the eastern USA and southern Ontario. Only (Marston, 1970) has a distribution overlapping with the other four species, being present in all of Mexico and the southwest of the USA.

Discussion

The data presented here increase the knowledge of Bombyliidae in Mexico but also reveals the deficiencies in sampling of the family in the country. The species list for the state increased three-fold, which demonstrates the lack of knowledge of the Bombyliidae fauna in this region. Almost all states of Mexico are in a similar situation but northern states appear to have higher diversity and should be priorities for sampling. Hull (1973) identified the northwest of Mexico as a species concentration area of Bombyliidae, but the northeast portion of the country may have the same species richness. Diversity of this family in the north of Mexico is probably much higher than recorded, as indicated by the richness in the south of USA which has similar environmental characteristics but much better sampling. Therefore northeast Mexico is possibly one of the most under sampled areas in the Nearctic region for Bombyliidae, given the great diversity of this family in the area, combined with the size of this part of the country. The study of Bombyliidae in the northern states of Mexico should be more of a priority than field work in the center or the southern states.

Most of the species collected in this study have a broad distribution in the USA but Mexican records are isolated. There are probably more species yet to be recorded from Coahuila and other Mexican states, especially species present in southern border states of the USA. Some species are recorded only from Coahuila in the northeast of Mexico but are also present in the northwest of the country. More studies are required to determine if these species have a disjunct distribution or if any are represented by distinct, cryptic eastern and western species.

Cuatro Ciénegas' biological and conservational importance has long been recognized for reptiles (McCoy 1984), birds (Contreras-Balderas 1984), plants (Pinkava 1984, Villarreal and Encina 2005), snails (Hershler 1984), Crustacea (Cole 1984) and particularly fishes (Minckley 1984), but little is known of other groups like insects. The insects contain 53% of the described species in the planet (Chapman 2009), so their distribution and diversity should be considered for conservation and natural reserve design. The diversity of insects, especially of Bombyliidae and similar arid-regions-diverse groups, increases the conservational value of Cuatro Ciénegas.

Conclusions

The data presented here indicates the significance of Cuatro Ciénegas for Bombyliidae diversity. Comparison with other nearby areas should be undertaken to confirm whether this area really is richer for this family. Data also reveal that true species richness of Bombyliidae is much higher than previously recorded. This could also be true for other insect groups. More funding should be destined for faunistic studies of megadiverse groups with ecological importance such as Diptera, Coleoptera, Hymenoptera and Lepidoptera. The information obtained from these studies might be used first to quantify the species richness and species exchange between areas (beta diversity) (Whittaker 1972) and later to propose conservation management schemes.