Allocladius aizaiensis (Wang) Ferrington Jr & Saether, 2011

Ferrington Jr, Leonard C. & Saether, Ole A., 2011, A revision of the genera Pseudosmittia Edwards, 1932, Allocladius Kieffer, 1913, and Hydrosmittia gen. n. (Diptera: Chironomidae, Orthocladiinae) 2849, Zootaxa 2849 (1), pp. 1-314 : 63-66

Allocladius aizaiensis (Wang) comb. n.

( Fig. 14 )

Pseudosmittia aizaiensis Wang, 1990: 273 .

Material examined: CHINA: Hunan, Aizai, along Dungke River , hand net, holotype male, 16. iv. 1988, S. Wang ( IHASW). – Paratypes: 29 males, 1 female, same data as holotype ( IHASW, UMSP, ZMBN, ZSM) .

Diagnostic characters: The male imago can be distinguished from other species with more than 2 acrostichals, superior volsella as basal swelling, large lobe-like accessory lobe of inferior volsella and virga consisting of only a rounded sclerotized plate, by having R 4+5 ending distal to end of M 3+4 and an antennal ratio of 1.12–1.44. The female can be separated from other known females with more than 2 acrostichals (except females of A. arenarius and A. nanseni ) by having 0–1 non-marginal seta on costa proximal to the end of R 4+5 and an LR 1 of 0.46. It may not be separable from females of A. arenarius or A. nanseni .

Male imago (n = 10–12, except when otherwise stated)

Total length 2.21–2.88, 2.60 mm. Wing length 1.33–1.76, 1.61 mm. Total length/wing length 1.55–1.73, 1.63. Wing length/length of profemur 2.84–3.06, 2.96. Coloration dark yellowish brown (paler and more yellow than A. soemmei ). Head ( Fig. 14 B ). AR 1.12–1.44, 1.32 (14). Terminal flagellomere 450–522, 494 µm (14) long. Temporal setae

3–9, 6, consisting of 1–3, 2 inner verticals, 1–2, 2 outer verticals and 0–4, 2 postorbitals. Clypeus with 7–12, 8 setae.

Cibarial pump, tentorium and stipes as in Fig. 14 C . Tentorium 107–135, 122 µm long, 23–39,30 µm wide. Stipes 96–

117, 112 µm long, 25–50, 34 µm wide. Palpomere lengths (in µm): 21–27, 25; 41–57, 48; 73–107, 87; 62–103, 88; 87–

137, 124. Third palpomere with 2–3, 2 lanceolate sensilla clavata.

Thorax ( Fig. 14 D ). Median antepronotal lobes well developed, antepronotum with 0–1, 1 weak lateral seta. Dorsocentrals 5–9, 7 (28), acrostichals 3–10, 6 (25), prealars 3–4, 3, supraalar 1. Scutellum with 6–8, 7 setae.

Wing ( Fig. 14 A ). VR 1.31–1.37, 1.34. Anal lobe well developed, projecting. Costal extension 11–30, 22 µm long. R 4+5 ending distal to apex of M 3+4; Cu 1 sinuate. Brachiolum with 1–2, 1 (27) setae; costal extension with 0–1, 0 (27) non-marginal setae; R with 1–7, 3 (27); R 1 with 0–1, 0 (27); R 4+5 with 0–1, 0 (27) setae, other veins bare.

Legs. Spur of front tibia 43–53, 48 µm long, spurs of middle tibia 21–25, 24 µm long and 18–23, 21 µm long, of hind tibia 39–46, 42 µm and 14–23, 19 µm long. Width at apex of front tibia 27–30, 29 µm, of middle tibia 25–30, 28 µm, of hind tibia 43–37, 35 µm. Comb of 11–16, 13 setae, shortest seta 16–23, 19 µm long, longest seta 27–37, 33 µm long. Lengths and proportions of legs as in Table 8.

Hypopygium ( Fig. 14 F ). Anal point 30–50, 43 µm long, including 23–32, 29 µm long base and 16–23, 20 µm long free apex; tergite IX with 10–22, 16 setae; laterosternite IX with 6–10, 8 setae. Phallapodeme 64–89, 81 µm long; transverse sternapodeme 46–69, 58 µm long, with oral projections weak or absent. Virga ( Fig. 22 E ) plate-like, sclerotized, 9–16, 13 µm long. Gonocoxite 174–208, 189 µm long; superior volsella in form of basal swelling reaching to 0.37–0.46, 0.43 gonocoxite length; inferior volsella and accessory lobe reaching to 0.57–0.64, 0.61 and 0.71–0.75, 0.73 gonocoxite length, respectively. Gonostylus 67–89, 78 µm long; megaseta 9–14, 11 µm long. HR 2.31–2.58, 2.42, HV 3.08–3.53, 3.33.

Female imago (n = 1)

Wing length 1.17 mm. Coloration slightly more pale than in male. Part of abdomen and cerci lost. All measurements and ratios within the variation of A. arenarius and A. nanseni with the following exceptions: Total length/ wing length 1.59. Length of spur of front tibia and width at apex of front tibia both 27 µm. BV 2 4.61, SV 3 4.31, BR 2 2.9. Seminal capsule partially with very weak microtrichia, about 5 µm long, gonocoxite not extended.

Pupa and larva

Unknown.

Remarks

Allocladius aizaiensis is very close to A. soemmei in the male imago, differing significantly only in having R 4+5 ending distal to the end of M 3+4, and less significantly in average size, coloration, antennal ratio and hind leg ratios. However, the female imagines are relatively different. The female of A. aizaiensis , at the moment, is not separable from A. arenarius and A. nanseni . There appears to be some subtle differences in the coxosternapodemes of these species. However, because of intraspecific variation in the latter two species and the lack of specimens to determine variation in this species, we cannot presently evaluate this significance of the variation that we have observed in this structure.

Wang (1990: 276) described a larva, which he thought possibly could be the larva of A. aizaiensis . This larva, however, is a Paraphaenocladius Thienemann.

Ecology and distribution

The imagines were caught at the mouth of Dunzhe River in the Hunan Province of China. The species probably occurs as larvae in wet sandy soils, but may be semiterrestrial to aquatic as are the larvae of A. nanseni and A. arenarius . The type locality is the only recorded locality.

Figures

FIGURE 14. Allocladius aizaiensis (Wang) comb. n., male. A—wing; B—head; C—cibarial pump, tentorium and stipes; D— thorax; E—virga; F—hypopygium, left dorsal aspect, right ventral aspect.

FIGURE 22. Allocladius conigerus (Freeman) comb. n., female. A—wing; B—antenna; C—dorsomesal lobe; D—ventrolateral lobe; E—apodeme lobe; F—genitalia, ventral view; G—genitalia, dorsal view.