Chiosperma Gagné, 2016

Gagné, Raymond J., 2016, Three new genera and three new species of Nearctic Lasiopteridi (Diptera: Cecidomyiidae: Cecidomyiinae) from Asteraceae and Caprifoliaceae, and the tribe Rhopalomyiini subsumed under Oligotrophini, Zootaxa 4158 (3), pp. 403-418 : 413-417

Chiosperma Gagné , new genus

Figs 6 , 32–41 .

Diagnosis. Although Chiosperma and Lonicerae both occur on Caprifoliaceae , the two genera are strikingly different. See Remarks under Lonicerae . The broad head with widely separated eyes, the curved R4+5 wing vein, the deep, splayed gonocoxites, and the large body size of Chiosperma show some resemblance to some Walshomyia spp. Unique characters of Chiosperma are the relatively long and narrow abdominal sclerites with the lateral group of tergal setae set closer to the anterior than to the posterior margin.

Description. Adult: Head ( Fig. 33 ): Wider than high, the eyes attenuated and separated by about 6 facet diameters at vertex; facets otherwise circular, contiguous except slightly farther apart near level of antennal bases. Antenna: scape with group of several medioventral setae; pedicel without setae; first and second flagellomeres connate. Male antenna with 15–16 flagellomeres ( Fig. 34 ); circumfila consisting of complete basal and distal rings connected by a vertical strand; straight setae encircling base below proximal circumfilum; many long, mostly ventral, basally curved setae from hooded alveoli situated between circumfilar rings. Female antenna with 14 flagellomeres ( Fig. 35 ), with short necks and irregular circumfila, and fewer hooded alveoli than in male. Frons extensively setose medially. Labrum not apparent. Labella ovoid, separate, each with several scattered setae and covered with microtrichia. Palpus of 1–2 segments of variable shape, each with a few setae and covered with microtrichia.

Thorax: Scutum with 4 longitudinal rows of setae with a few scales intermixed. Scutellum setose laterally, setae sparse medially. Anepisternum with scales on dorsal half; anepimeron setose; pleura otherwise bare. Wing ( Fig. 6 ): C not broken just beyond junction with R4+5; R4+5 strongly curved apically, reaching C appreciably beyond wing apex; CuA forked. Acropods ( Figs 36–37 ): claws stout, strongly curved beyond midlength, without basal tooth; empodia broad, slightly longer than claws; pulvilli about ¾ length of claws.

Male abdomen (generally as for female, Fig. 32 ). Tergites first through eighth and second through seventh sternites with anterior pair of trichoid sensilla, closely approximated on sternites; sternite eight without trichoid sensilla. First through sixth tergites rectangular, about as long as wide, with mostly 2–3 rows of elongate posterior setae, many lateral setae, these set closer to anterior than to posterior margins of tergites, surface elsewhere mostly bare; seventh tergite slightly shorter than preceding, 2 rows of posterior setae, the lateral setae placed close to midlength, otherwise as for preceding tergite; eighth tergite shorter than preceding, posterior setae eliminated but many lateral setae present. Sternites second through seventh rectangular, longer than wide, evenly pigmented, each with mostly three rows of long setae posteriorly preceded by an area with few short setae and scales, and, anteriad but not extending to anterior pair of trichoid sensilla, covered with large and small setae mixed with scales. Pleura covered with long, narrow scales. Terminalia ( Figs 40–41 ): ninth tergum with short, setose sclerite, weak or broken medially; cerci ellipsoid, with numerous apicodorsal and apicoventral setae; hypoproct deeply incised, each resulting lobe with 4–5 apical setae; gonocoxite greatly expanded ventrally, with numerous, closely-set setae, mediobasal lobe subdivided, the much shorter dorsal section long-microtrichose (not shown in Fig. 41 ), ventral section large, cylindrical, broadly rounded apically, adjacent to aedeagus, covered with short microtrichia, with 3–4 apical setae; gonostylus long, nearly evenly cylindrical, evenly covered with closely-set setae, the surface entirely covered with microtrichia, apical tooth wide, pectinate; aedeagus cylindrical, much narrowed beyond midlength.

Female abdomen ( Figs 32 , 39 ): Trichoid sensilla and vestiture of first through eighth segments generally as in male with addition of pair of trichoid sensilla present and placed far apart on eighth sternite. First through seventh tergites about 3/4 as long as wide; eighth tergite half as wide and shorter than seventh. Ovipositor: protrusible, short, cylindrical, eversible part bare, protrusible part about as long as seventh tergite, with slender but solid lateral sclerite along full length on each side, an oval, pigmented, long-setose ventroapical area present on each side; cerci discrete, bilaterally flattened, with short setae, some near apex stout, peglike; hypoproct concave apically, each resulting lobe with 2 setae.

Pupa ( Fig. 38 ): Antennal bases enlarged, conical, pointed apically and curved ventrally. Vertex on each side with long seta situated on conspicuously raised base. Face smooth, without lobes, without discernable setae. Prothoracic spiracle barely longer than wide. Abdominal terga, pleura and sterna evenly covered with short microtrichia.

Larva, third instar (specimen not optimal): Stout, cylindrical. Head capsule short-conical. Spatula not present. Terminal papillae eight, the setae no longer than width of papillar base. Integument with rounded verrucae dorsally, spiculose laterally and ventrally.

Type species, Chiosperma turgidum Gagné

Etymology. The name Chiosperma is Greek for snowberry, the host's common name. The gender is neuter.

Remarks. See under Lonicerae above.

Figures

FIGURES 4 – 6. Wings. 1, Helianthecis capitum. 2, Lonicerae russoi. 3, Chiosperma turgidum. Line = 1 mm.

FIGURES 31 – 32. Female abdomens, end of fourth segment to cerci (dorsolateral). 31, Lonicerae russoi. 32, Chiosperma turgidum. Letter a: position of lateral setae on fifth tergite, at midlength on L. russoi, farther anteriad on C. turgidum; b: presence of scales on L. russoi, their absence on C. turgidum; c: weakly sclerotized area of seventh sternite anteriad of the posterior setal rows; d: lateral sclerite of protrusible part of the ovipositor. Line = 0.5 mm.

FIGURES 33 – 39. Chiosperma turgidum. 33, Head (frontal, flagella removed). 34, Male third flagellomere (ventral). 35, Female third flagellomere (ventral). 36, Claw and empodium (lateral). 37, Acropod (mesal). 38, Pupal anterior parts (ventral, part of an antennal base missing). 39, End of ovipositor (lateral).

FIGURES 40 – 41. Chiosperma turgidum. 40, Male terminalia, one gonopod removed, one mediobasal gonocoxal lobe visible between lobes of hypoproct (dorsal), aedeagus not shown. 41, Male terminalia (lateral).