Gelastagathis Sharkey

Sharkey, Michael J. & Chapman, Eric G., 2015, The Nearctic genera of Agathidinae (Hymenoptera: Braconidae) with a phylogenetic analysis, illustrated generic key, and the description of three new genera, Zootaxa 4000 (1), pp. 49-72 : 59-60

Gelastagathis Sharkey NEW GENUS

( Figs. 3 , 4 )

Type species. Gelastagathis grisselli Sharkey sp. n.

Diagnosis. Mandibles thickened, not dorsoventrally flattened. Head wide with temples expanded. Ventral margin of clypeus projecting from surface of face and mouthparts appearing cyclostome. Apex of hind tibia with unmodified cylindrical pegs. Metasomal median tergites lacking carina and microsculpture. The mandibles are similar to those of Agathirsia and Crassomicrodus as is the lack of sculpture on the metasoma. Members of Gelastagathis can be differentiated by the shape of the clypeus, head, and tibial pegs.

Description ♂. Head. Temple robust and head wide; lateral carina on frons (as in members of Alabagrus ) absent; interantennal space with slightly raised pyramidal prominence; gena not extended ventroposteriorly into sharp prominence; gena lacking sharp angle posterad eye; clypeus projecting anteriorly, ventral margin concave or straight; large space between clypeus and mandibles, thus appearing to have the cyclostome condition; mandible robust, thick and cylindrical, not dorsoventrally flattened; labial palpus with 4 segments, third segment more than ½ length of apical segment; apical antennomere lacking nipple-like process. Mesosoma . Propleuron weakly convex ventrally and lacking a sharp bump; mesopleuron mostly smooth and shining, sculpture restricted to small pits in sternaulus; notauli impressed and mostly smooth with distinct to very weak pits posteriorly; posteroscutellar depression absent and sculpture absent in this area; propodeum mostly smooth to entirely rugose, with pair of weak diverging longitudinal carinae that define a medial area; sclerite between hind coxal cavities and metasomal foramen narrow but complete, its ventral margin situated ventral to dorsal margin of hind coxal cavities. Legs. Fore tibia lacking dull pegs but some acute spines are thickened; mid and hind tibia with blunt apical or preapical pegs; all tarsal claws with basal lobe. Wings. Fore wing RS+M vein mostly absent; second submarginal cell triangular and petiolate; fore wing 3RSb straight and strong throughout; hind wing r and r-m cross veins absent; hind wing vein CUb tubular as a short stub with a long, pigmented, non-tubular, extension; wings weakly infuscated. Metasoma. First median tergite quadrate, only slightly longer than wide apically, smooth, lacking sculpture and carinae OR with weak longitudinal striae; second and third median tergites smooth, lacking any distinct depressions or sculpture; length of ovipositor unknown.

Biology. Based on the thick mandibles, it is likely that members have life histories similar to those of Agathirsia , which have similarly robust mandibles, and attack Lepidoptera that pupate in the ground; the mandibles are used to dig up to the ground surface after emergence (Pucci and Sharkey 2005).

Distribution. Known from the two specimens of G. grisselli from Texas and one specimen of G. frosti from Massachusetts. Both species are described below.

Etymology. From the Greek agathis , meaning “ball of thread”, and the Greek galao, meaning “laugh”. The latter word is a reference to the projecting clypeus that makes the face appear amused ( Fig. 3 ). The gender is feminine.

Figures

FIGURE 3. Gelastagathis grisselli holotype ♂. a. lateral habitus. b. dorsal habitus. c. wings, arrow shows nebulous Cub vein. d. head, anterior view, arrows show ventral margin of clypeus and mandible. e. head, dorsal view, arrow shows expanded temple. f. propodeum and first metasomal median tergite (T 1), arrow shows T 1.

FIGURE 4. Gelastagathis frosti holotype ♂. a. lateral habitus. b. dorsal habitus. c. wings. d. propodeum and first metasomal tergum, arrows point to longitudinal carina on propodeum and striae on tergum. e. head frontal view, showing thickened mandible. f. mesoscutum, showing notauli.