Jeanchazeauia, Irwin & Winterton & Metz, 2020

Irwin, Michael E., Winterton, Shaun L. & Metz, Mark A., 2020, New stiletto flies from New Caledonia (Therevidae, Agapophytinae), ZooKeys 984, pp. 83-132 : 83

Jeanchazeauia gen. nov.

Type species.

Jeanchazeauia nubilosus sp. nov., here designated.

Diagnosis.

Frons width slightly wider than ocellar tubercle with little sexual dimorphism; postocular macrosetae arranged in one row in both sexes; femoral velutum patches absent; hind femur with anteroventral macroseta(e) subapically, frequently as a row; hind femur with series of posteroventral macrosetae; cell br with scattered microtrichia; male gonocoxite lacking medial atrium and velutum patch; female tergite VII with broad anteromedial process; tergite VIII narrowly band-like and ‘T’ -shaped.

Description.

Antennal length variable, longer than head to equal to head length; flagellum cylindrical, slightly tapered distally, length subequal to combined length of scape and pedicel; scape narrow, elongate (> 3 × pedicel length); upper frons flat, slightly raised around base of antennae; head shape in profile higher than long; male frons width at narrowest point slightly wider than ocellar tubercle, little sexual dimorphism in frons width; parafacial without setae; postocular macrosetae arranged in one row immediately lateral of ocellar tubercle in both sexes; prosternum without setae; abdominal tergite II all setae uniform and regular in length; fore- and hind femoral velutum patches absent; fore- and midfemoral macrosetae absent; hind femur with anteroventral macroseta(e) subapically, frequently as a row; hind femur with posteroventral macrosetae short, present as series around middle of segment; posterior surface of midcoxa without setae; hind femur and tibia relatively long compared to other legs; post-spiracular setae absent. Scutal chaetotaxy (pairs): np, 1-2; sa, 1; pa, 1; dc, 0 or 1-2 (minute); sc, 1; wing cell m3 open, cell br with scattered microtrichia, not restricted to wing fold; uniform wing dark infuscation to strongly banded. Male genitalia with dorsal apodeme of aedeagus ‘T’ -shaped, distiphallus narrow, ventral apodeme with forked arms divergent; gonocoxite with posteromedial margins proximal to each other, velutum pubescence absent, inner gonocoxal process present, ventral lobe small, usually rounded apically; female genitalia with tergite VII with broad anteromedial process; tergite VIII narrowly band-like and ‘T’ -shaped, with narrow anteromedial process; female acanthophorite setae with two sets present (A1 & A2); A1 slender, elongate acuminate apically, A2 series slightly reduced in size; sternite VIII cup-like, extensively pilose, greatly emarginate posteromedially; spermathecal sac elongate and rounded apically, not lobed; three spermathecae joining to spermathecal duct near junction of bursa copulatrix.

Etymology.

This new genus is named in honour of Dr Jean Chazeau, who extended unbridled hospitality and assistance to the members of our expeditions during our stays in New Caledonia. Gender is masculine.

Comments.

Of the three species in this genus, the male is known only for J. nubilosus sp. nov., which exhibits distinct sexual dimorphism in wing patterning. The modification of both tergite VII and tergite VIII in the female appears unique to this genus amongst all Therevidae . Although members of some Xestomyzinae (e.g., Lynborgia ammodyta Irwin, 1973), Agapophytinae (e.g., Agapophytus bicolor ( Kröber, 1928)) and Therevinae (e.g., Apenniverpa venezuelensis Webb, 2005) have a modified ‘T’ -shaped female tergite VIII remarkably similar in shape to members of Jeanchazeauia gen. nov., in all cases tergite VII is not modified at all. Species in this genus are relatively rare compared to the more widely encountered Calophytus gen. nov. and appear to be more restricted to montane rainforest habitats (Figs 31 , 32 ).

Included species.

Jeanchazeauia amoa sp. nov., J. nubilosus sp. nov., and J. rufinatus sp. nov.

Figures

Figure 31. Natural habitats of New Caledonian agapophytine stiletto flies A Riviere Bleue Reserve, sclerophyll forest and maquis scrub, habitat of C. chazeaui sp. nov., C. grandiosus sp. nov., C. schlingeri sp. nov., and J. nubilosus sp. nov. B Pindai Peninsula, tropical dry forest, habitat of C. webbi sp. nov. C Mount Dzumac, rainforest, habitat of J. nubilosus sp. nov. D Mount Dore, rainforest and dry sclerophyll forest E Mount Dore, Malaise trap in flyway (photographs by Michael E. Irwin).

Figure 32. Natural habitats of New Caledonian agapophytine stiletto flies A Mount Aoupinie, rainforest, habitat of C. monteithi sp. nov. B Mount Ningua, rainforest, habitat of J. nubilosus sp. nov. C Mount Mandjelia, habitat of C. grandiosus sp. nov. (photographs by Michael E. Irwin).