Cassidoides cornutus, Jaschhof & Jaschhof, 2020

Jaschhof, Mathias & Jaschhof, Catrin, 2020, The Porricondylini (Diptera: Cecidomyiidae: Porricondylinae) of Sweden revisited: descriptions of nineteen new species of ten genera, including a new genus, Zootaxa 4728 (2), pp. 151-182 : 152-154

Cassidoides cornutus sp. nov.

Figs 1–3

Diagnosis. Cassidoides cornutus , a typical member of the genus Cassidoides , differs from the congeneric species by the aedeagal apodeme being shorter than the gonocoxae, and by having a pair of long, sclerotized gonocoxal processes shaped like horns or tusks ( Fig. 2 , ↓ 1,2). The only other Cassidoides with this kind of processes is C. fulvus , but there they are oriented markedly dorsad, not strictly posteriad as in C. cornutus . Also, the aedeagal apodeme of C. fulvus is markedly longer than the gonocoxae ( Jaschhof & Jaschhof 2013: fig. 145B). Females and preimaginal stages of C. cornutus are unknown.

Other male characters. Body size 1.2 mm. Head. Eye bridge 3–4 ommatidia long at vertex. Antenna longer than body, shorter than wing. 12 flagellomeres; apical flagellomere long, composed of two bodies; circumfila on all flagellomeres. Neck of fourth flagellomere 1.7 times as long as node ( Fig. 3 ). Palpus slightly shorter than head height, 4 setose, subcylindrical segments, apical segment longest of all. Thorax. Pronotum and anepisternum each with 1 seta; anepimeron with 3 setae. Wing. Length / width ratio 3.1. M 4 absent. CuA ending well before wing edge.

Legs. Foreleg: femur 1.3 times as long as tibia, tibia 0.8 times as long as T 2. Genitalia ( Figs 1–2 ). Gonocoxal synsclerite: ventral emargination without clear contours, occupied by aedeagus which is unusually strongly developed in this species; a pair of short, subtriangular, largely membranous processes on either side of the emargination that are connected through a membrane with the horn-shaped processes; ventroposterior portions subtriangular; dorsoposterior portions slightly extended into rounded lobes. Gonostylus compact, strongly convex, outer surface with dense, large setae, inner (medial) surface sparsely setose; pectinate claw large, with dent along the base. Aedeagus present as membranous, rather sharply contoured bulge with microtrichose apex; ejaculatory ducts unusually well discernible despite their membranous texture. Aedeagal apodeme short, thick, with broadened, membranous apex. Parameres well sclerotized, forming a reverse V with the arms touching but apparently not merged with each other; apices broadened and bent dorsally.

Etymology. The Latin adjective cornutus means cornute, relating to the horn-shaped gonocoxal processes found in this species.

Type material. Holotype. Male, Sweden, Dalarna, Orsa , 4 km NW Ejheden (W of Lake Långjämnaren), recently burnt forest of pine, spruce and birch, 26 June–18 July 2018, Malaise trap, M. & C. Jaschhof (spn. CEC 2520 in NHRS).

Note on the type locality. The Malaise trap that captured the holotype specimen of C. cornutus was located in a forest that only several weeks prior to the trapping period was the scene of an extensive, managed forest fire. As C. cornutus is known from no other locality than this firesite, one might speculate it is pyrophilic, for which we have no hard evidence, though.

Figures

FIGURES 1–5. Male morphology of Cassidoides cornutus (1–3) and Coccopsilis pectinata (4–5), holotypes. 1: Parameres and apex of aedeagal apodeme, ventral. 2: Genitalia, ventral. 3: Fourth flagellomere, lateral. 4: Genitalia, ventral. 5: Fourth flagellomere, lateral. Scales for 1, 0.025 mm; for 2–5, 0.05 mm. Arrows refer to characters described in the diagnoses.