A new species of Octaspidiotus (Hemiptera, Diaspididae) from China.

Adult females of a new species of armored scale insect, Octaspidiotus shanghaiensis sp. n. are described and illustrated from specimens collected in China. A key is provided for the all described species of Octaspidiotus.

Introduction

Scale insects (: ) are sap-sucking parasites which are small (generally less than 5 mm) and cryptic in their habitats (Gullan 1997), with at least 30 families and approximately 8000 species (García et al. 2016). Containing more than 2500 described species, is the largest species-rich family in the (García et al. 2016). Adult diaspidid females are sessile and permanently reside on their host plants (Gullan 1997). Adult females have the complete loss of the legs, the reduction of the antennae to a single segment and the modification of the abdomen into a specialized pygidium for forming the test, and these characteristics are the primary recognition features for these insects (Andersen 2010; Balachowsky 1948). Armored scale insects are important agricultural pests and have colonized a diverse set of plant species. They are distributed on every continent except Antarctica (Andersen 2010).

Although the family classification is controversial, the and the are the two major subfamilies. The genus was established as a member of the former subfamily by MacGillivray (1921), with Maskell as its type species. However, two species that he transferred from are not now included in this genus. Since then, many additional species were described and added to by other authors (Borchsenius 1966; Tang 1984; Tang and Chu 1983; Takagi 1984).

Takagi (1984) showed that (Green) was not a member of because the distinguishing characteristics were invalid. Currently, this genus is comprised of 14 valid species, eight of which are known to occur in China (García et al. 2015; Tang 1984; Takagi 1984). There are only two species recorded from Oceania, the other 12 species being distributed throughout East Asia.

Recently, one new species of was discovered from China. It was described and illustrated in this paper, bringing the number of recognized species in the genus to 15, of which nine species are recorded from China. A key to all known species of is provided.

Materials and methods

In this paper, the terminology described by Henderson (2011) has been used. This publication also includes illustrations for most of the species treated herein. All measurements are presented in micrometers (μm). Measurements were made using NIT-Elements D tools.

The abbreviations L1, L2 and L3 are short for the median, second, and third pygidial lobes, respectively.

All specimens have been deposited in the .

Entomological Museum, Northwest A & F University, Yangling, Shaanxi, China

Taxonomy

MacGillivray, 1921

Takagi, 1957: 35. Junior synonym.

Type species.

Maskel, 1892.

Generic diagnosis.

Adult female. Body is oval to rounded; derm membranous except pygidium. Cephalothorax. Antennae with 1 seta. No trilocular pores associated to the spiracles. Pygidium. With 3-4 pairs of lobes, never bilobed. Median lobes (L1) well-developed, with notches on both margins or only present on the outer margin. Second lobes (L2) smaller than L1, with notches on both laterals or only present on the outer lateral. Third lobes (L3) similar to L2. Fourth lobes (L4) small and pointed PageBreakapically, only present in . Marginal setae occurring on dorsal bases of L2 and L3, lanceolate, broadened and flattened. Plates are well-developed, fimbriate on the outer margin in most species, occurring laterally and even extended to the abdominal segment IV. Paraphyses absent on pygidial margin. Ducts. Dorsum has one-barred type macroducts, that are aligned in some species. Ventral microducts are scattered. Anal opening is toward the apex of the pygidium, more or less elongate. Vulvar opening situated anterior to anal opening. Perivulvar pores are quinquelocular, present or absent, if present, in four groups.

Remarks.

This genus is very close to Bouché, 1833 and Takagi, 1984 in terms of pygidial lobes and pygidium, but can be distinguished by the form of the dorsal marginal setae occurring on L1 and L2 which are lanceolate, broadened and flattened, while these setae in the other two genera are simply thickened.

sp. n.

http://zoobank.org/07E3AD76-AF7A-4130-92CC-0C7895FF0A0F

Figures 1–7

Figure 1–7.

sp. n. adult female: 1 habitus 2 detail of antenna 3 detail of anterior spiracle 4 dorsal 1-barred duct 5 pygidium 6 quinquelocular pores 7 detail of the end of pygidium margin.

Material examined.

Holotype: 1 adult female: CHINA: Changfeng Park, Shanghai City, 11. IV. 2015, Hongliang Li (NWAFU).

Paratypes. 3 adult females: same data as the holotype (NWAFU).

Diagnosis.

Description, n = 4. Adult females. Field characters: adult female scale nearly oval, flat, dark greyish in colour; exuviae nearly central.

Slide-mounted: Adult female not pupillarial, 810–952 um long (holotype 905 μm long); 756–883 μm wide (holotype is 881 μm in the widest part of the body). Body outline oval, derm membranous except for pygidium (Figure 1). Cephalothorax. Antennae each with 1 seta (Figure 2), distance between antennae is 164.3 μm. Prespiracular pores absent (Figure 3). Pygidium (Figure 5). The pygidium has three pairs of lobes: L1 are well-developed, a small mesal notch is present on or near the apex, and a relative larger notch is present on or near the apex of the outer margin. L1 is 6.7–7.2μm wide and the distance of two lobes of L1 is 1.5–2.1μm wide. Median lobes separated by a space 0.2–0.3 times the width of L1. L2 smaller than L1, with one notch on the outer margin. L3 similar to L2, but smaller. Lanceolate setae on L2 and L3 shorter than these lobes themselves. Plates (Figure 5 and 7) one pair of pointed plates between L1, not extending to the apex of the lobe; 2 pairs of plates between L1 and L2, apically fringed with few fine bifurcated; with 3 pairs of plates similar in size and shape between L2 and L3; with 6–7 pairs of plates lateral to L3. Ducts (Figure 4 and 5). Dorsal macroducts 1-barred-shaped. No marginal macroduct between median lobes. One marginal macroduct between L1 and L2, two between L2 and L3, and 3–4 present between L3. Dorsal submarginal macroducts about the same size as marginal macroducts which are 30–35 μm long. Total dorsal macroducts on dorsum in submarginal and marginal areas of pygidium on each side of body 32–44 (44 in holotype). Dorsal macroducts on abdomen segment IV shorter than on pygidium, with 5–6 macroducts on margin PageBreakof abdomen segment IV. Ventral microducts are fewer and more scattered than the dorsal macroducts. Anal opening (Figure 5) 22.4–25.5 μm long in diameter, located 46.2–48.7 μm between the base of the anal opening and the base of L1. Perivulvar (Figure 5 and 6) present in an arc, divided in four groups, 9–12 anterolaterally and 8–9 posterolaterally.

This species is similar to Tang, 1984 in the body shape and the pygidial lobes, but can be distinguished by the following characters (those for in parentheses): 1) without marginal macroduct on abdomen segment III (with 3–4); 2) the three plates between L2 and L3 all equally shaped (the third plate is narrower than the first and the second plates); 3) L1 is separated by a space 0.2–0.3 times the width of each median lobe (by a space 0.5 times the width of each L1); 4) without marginal macroducts between L1 (present).

Host.

(L.)

Etymology.

The specific epithet is named after Shanghai, the type locality.

Distribution.

China (Shanghai).

Key to the adult females MacGillivray

denotes Chinese species

1	With 3 pairs lobes on pygidium, L4 absent	2
–	With 4 pairs lobes on pygidium, L4 present as small, pointed, sclerotized processes	Octaspidiotus subrubescens (Takahashi)
2	Lanceolate marginal setae occurring on dorsal bases of L2 and L3 not extending to the apex of L2 and L3, respectively	3
–	Lanceolate marginal setae occurring on dorsal bases of L2 and L3 more-or-less extending to the apex of L2 and L3, respectively	13
3	All lobes hippocrepiform, without notches on margin of L1	Octaspidiotus bituberculatus Tang*
–	Lobes normal, with notches on margin of L1	4
4	With notches on outer margin of L1	Octaspidiotus australiensis Kuwana
–	Notches present on both margins of L1	5
5	Three plates occurring between L2 and L3 are not equal in width	6
–	Three plates occurring between L2 and L3 are equal in width	10
6	Plates between L1 bifurcate or pointed apically; distance between L1 narrower than 1/2 of each lobe of L1; with 6 plates occurring lateral to L3	Octaspidiotus cymbidii Tang*
–	Plates between L1 fringed; distance between L1 no less than 1/2 of each lobe of L1; with no less than 7 plates occurring on the outer lateral to L3	7
7	With notches on both margins of L3; both second and third plates between L2 and L3 narrower than first plates between L2 and L3	Octaspidiotus rhododendronii (Tang)*
–	With notches on outer margin of L3, without notches on mesal margin of L3; Second or third plates between L2 and L3 narrower than first plates between L2 and L3	8
8	Second plates between L2 and L3 narrower than first and third plates between L2 and L3	9
–	Third plates between L2 and L3 narrower than first and second plates between L2 and L3	Octaspidiotus yunnanensis (Tang & Chu)*
9	With 22–24 perivulvar pores and 35–42 dorsal macroducts on pygidium	Octaspidiotus tamarindi (Green)
–	With 43–60 perivulvar pores and 54–65 dorsal macroducts on pygidium	O . tripurensis Takagi
10	With notches on mesal margin of L2; distance between L2 and L3 equal to 1/5 of each lobe of L1; plates between L1 bifurcate or pointed apically	Octaspidiotus shanghaiensis sp. n.*
–	With notches on both margins of L2; distance between L2 and L3 more than 1/3 of each lobe of L1; plates between L1 fringed	11
11	Body strongly sclerotized at maturity	12
–	Body remaining membranous	Octaspidiotus nothopanacis (Ferris)*
12	Number of perivulvar pores less than 30; with 7 plates occurring on the outer side of L3	Octaspidiotus stauntoniae (Takahashi)*
–	Number of perivulvar pores more than 30; with 8 plates occurring on the outer side of L3	Octaspidiotus calophylli (Green)
13	With notches on outer margin of L2 and L3; with no more than 7 plates occurring on the outer side of L3	Octaspidiotus pinicola (Tang)*
–	With notches on both margin of L2 and L3; with no less than 8 plates occurring on the outer side of L3	14
14	With more than 80 dorsal macroducts and 32–47 perivulvar pores	Octaspidiotus multipori (Takahashi)
–	With less than 80 dorsal macroducts and 23–29 perivulvar pores	Octaspidiotus machili (Takahashi)*