Atherigona (Acritochaeta) culicivora, Kovac & Pont & Deeming, 2023

Kovac, Damir, Pont, Adrian C. & Deeming, John C., 2023, Atherigona culicivora, new species (Insecta: Diptera: Muscidae), a bamboo shoot-fly feeding on mosquito larvae, Raffles Bulletin of Zoology 71, pp. 583-595 : 584-588

Atherigona (Acritochaeta) culicivora , new species

( Figs. 1–34 )

Material examine d. Holotype: male ( SMF D 3717 ; Figs. 1, 2 ), North Thailand, Mae Hong Son Province, Pangmapa district, near Ban Nam Rin , larvae in water-filled bamboo stump of Cephalostachyum pergracile , B27/07, reared to adult and emerged 27 September 2007, coll. D. Kovac.

Paratypes: 1 female with 1 puparium ( SMF D 3718 ), data as for holotype ; 1 male and 1 female ( ZRC and FRIM) with 2 puparia, Peninsular Malaysia, Ulu Gombak FSC, reared from larvae in bamboo shoot stump, A/39, adults emerged 27 September 1995, coll. D. Kovac ; 1 male, 1 female ( NHMUK) and 1 female ( SMF D 3721 ), Peninsular Malaysia, Ulu Gombak FSC, on freshly cut bamboo stump, A2/7, 18 September 1995, coll. D. Kovac ; 1 male, 1 female ( NHMUK) and 1 male (PMCSNHM), Peninsular Malaysia, Ulu Gombak FSC, reared from larva in bamboo shoot stump, A/45, adults emerged 5 September 1995, coll. D. Kovac ; 1 female with puparium ( NMWC), Peninsular Malaysia, Ulu Gombak FSC, reared from larva in bamboo shoot stump, A/38, adult emerged 27 August 1995, coll. D. Kovac ; 1 male ( NMWC) , 2 females ( SMF D 3723 and D 3724) with 3 puparia, Peninsular Malaysia, Ulu Gombak FSC, larvae from decaying bamboo shoots, A2/68, 26 November 1995, coll. D. Kovac ; 3 females ( ZRC, NHMUK, NMWC), Peninsular Malaysia, Ulu Gombak FSC, freshly cut apical part of bamboo shoot of Gigantochloa scortechinii lying on the ground, BS66/07, 16 August 2007, coll. D. Kovac ; 1 male with puparium ( SMF D 3726 ), Peninsular Malaysia, Perak, near Sungai Halong, Temengor , larva collected 4 October 1993 , in water in felled bamboo shoot ( Gigantochloa latifolia ), adult emerged 13 October 1993, coll. D. Kovac; 1 male ( SMF D 3727 ) , 1 larva, North Thailand, Mae Hong Son Province, Pangmapa district , near Pha Mon , 2 larvae collected 25 June 2004, in water-filled stump of a young bamboo shoot of Dendrocalamus giganteus , B12/04, one reared to adult and emerged 2 June 2004, coll. D. Kovac; 1 female ( SMF 3728 ), bred from egg collected in North Thailand, Mae Hong Son Province, Pangmapa district, near Ban Nam Rin , from a bamboo shoot stump of Cephalostachyum pergracile , 1 October 2007, coll. D. Kovac. A number of eggs, larvae and puparia in alcohol are in SMF and NMWC.

Specimens of this species have also been collected in Malaysia, Genting Highlands, Pahang state, by E. Makovetskaya and N. Vikhrev, and were identified by N. Vikhrev when reviewing this manuscript. They are deposited in the Zoological Museum of Moscow University, Moscow, Russia .

Etymology. The name of the species is derived from the Latin ‘culex’ (midge) and ‘vorare’ (to devour), and refers to the feeding habits of the larvae.

Diagnosis. A large species of the subgenus Acritochaeta Grimshaw ( Figs. 1–3 ), with shining fronto-orbital plates, mid femur with 2 posterior preapical setae, and hind femur without a dorsal preapical seta. Males are easily recognised by secondary sexual characters: wing-tip with a dark cloud ( Fig. 7 ) and fore tarsomere 5 flattened and modified in structure and bristling ( Fig. 6 ).

Description. Male. Head ( Fig. 4 ). All setae and setulae black. Ground colour dark brown beneath the pruinosity. Most of occiput subshining, grey dusted along eye-margin; ocellar tubercle grey pruinose; fronto-orbital plate shining dark brown, undusted; parafacial, face, gena and lower occiput light grey pruinose. Frons at lunula one-third width of head at this point. 6–7 pairs of inclinate frontal setae. Antennal scape and pedicel mostly orange to black; postpedicel entirely dark brown; arista yellow on basal half, otherwise brown. Postpedicel (and face) unusually long, almost 6 times as long as broad. Palpus ( Fig. 4 ) dark brown, elongate, with fine setulae along ventral surface. Prementum dark brown, shining, with some slight grey dust.

Thorax. Ground colour of scutum mainly dark; postpronotal lobe, notopleuron and postalar callus yellow; pleura mostly brown, sometimes extensively yellow; scutellum yellow, narrowly dark at base. Basisternum yellow, shining. Scutum densely grey dusted on the dark area, with 3 narrow dark dusted vittae along the acrostichal and dorsocentral rows, the acrostichal vitta much narrower than the grey-dusted area separating it from each dorsocentral vitta. Yellow lateral scutal areas and pleura whitish dusted. Scutellum undusted. Presutural acrostichal setulae in 4–5 rows. 1 strong and 1–2 weak proepimeral setulae. Katepisternal setae 1+2, lower one slightly closer to posterior than to anterior seta and less than half as long as posterior seta. Disc of scutellum with very numerous discal setulae; basal lateral seta half as long as lateral seta.

Legs ( Figs. 5–6 ). Mostly yellow; fore femur with a dark dorsal patch on apical third; fore tibia in apical half and all tarsomeres brown, tarsomere 5 on all legs partly yellow. Fore coxa elongated and curved, twice as long as mid or hind coxa and just over half as long as fore femur, with erect, fine, pale hairs along dorsal surface. Fore femur ( Fig. 5 ) with a weak dorsal concavity in apical half and a preapical dorsal tuft of short black setulae; 2 (–3) posteroventral setae before apex, otherwise without setae. Fore tibia ( Fig. 5 ) without setae except at apex. Fore tarsus ( Fig. 6 ) with tarsomere 5 elongated and dorsoventrally flattened, the tip modified into a series of spines and projections, without the usual paired pulvilli and median claw. Mid femur with 2 posterior preapical setae. Hind femur without a dorsal preapical seta above the anterodorsal row; hind femur and tibia without ventral keels.

Wing ( Fig. 7 ). Clear except for a broad dark cloud at tip, from midway between veins R 1 and R 2+3 to tip of vein R 4+5, appearing more extensive in mature (fully hardened) specimens. Microtrichia relatively sparse and wing surface thus appearing glassy. Cross-vein r-m at or slightly beyond middle of discal medial cell dm. Calypters yellow, especially lower one. Knob of haltere creamy-white.

Abdomen ( Fig. 8 ). Ground colour entirely yellow, without any dark spots or markings. Tergites thinly dusted and subshining.

Terminalia ( Figs. 9–12 ). Hypopygial prominence and trifoliate process absent. Cercal plate ( Figs. 9, 10 ) strongly bowed in lateral view. Surstylus ( Figs. 9, 10 ) bifid almost from base.

Figures

Figs. 1–3. Atherigona culicivora, new species: 1, holotype male, lateral view, body length ca. 6 mm; 2, holotype male, dorsal view; 3, two males, lateral view, showing terminalia (Malaysia, Pahang state, Genting Highlands, 3.381°N 101.779°E, at 800 m, 1 to 7 December 2019; photos: E. Makovetskaya and N. Vikhrev).

Figs. 4–12. Atherigona culicivora, new species. Male: 4, head, lateral view; 5, foreleg, posterior view; 6, tarsomere 5 of foreleg, dorsal view; 7, wing; 8, abdomen, dorsal view; 9, apex of abdomen, lateral view; 10, hypopygium, lateral view; 11, epandrium and cercal plate, dorsal view; 12, tip of cercal plate; cp – cercal plate; ss – surstylus; t – tergite.

Figs. 13–15. Atherigona culicivora, new species. Female: 13, ovipositor, ventral view; 14, tip of ovipositor, dorsal view; 15, sternite 7.

Figs. 16–17. Atherigona culicivora, new species. Egg and third instar larva: 16, egg, lateral surface of shell; 17, third instar larva, buccal cavity spicules.

Figs. 18–19. Atherigona culicivora, new species. Third instar larva: 18, cephalopharyngeal skeleton, lateral view; 19, cephalopharyngeal skeleton, anterior section from above.

Figs. 20–23. Atherigona culicivora, new species. Third instar larva (20, 21) and puparium (22, 23): 20, right hand side of anal plate; 21, creeping welt spicules; 22, puparium, outline in dorsal view; 23, first thoracic segment in dorsolateral view.

Figs. 24–27. Atherigona culicivora, new species. Last instar larva (SEM photographs): 24, head region; 25, maxillary ring; 26, anal division with posterior spiracles; 27, apical surface of the posterior spiracle.

Figs. 28–34. Atherigona culicivora, new species. Habitat and life stages: 28, larval habitat: A stump of a young bamboo shoot of Gigantochloa scortechinii in Peninsular Malaysia with A. culicivora females and other flies breeding in the shoots, such as Tipulidae and Drosophilidae; 29, a gravid A. culicivora female, feeding on the wall of a cut bamboo shoot, photographed in the field; 30, two larvae floating in the water, the black posterior spiracles are attached to the water surface, note mosquito larvae of different sizes; 31, larva feeding on a mosquito larva; 32, eggs deposited on the wet bamboo shoot sheath; 33, larva pupariating on the bamboo wall above the water surface, note the foam surrounding the anterior part of the body; 34, three puparia attached to the bamboo wall.