Tanyxiphium Huber 2015

TANYXIPHIUM Huber, 2015 (Figs 321–329) Tanyxiphium Huber, 2015a: 57. Type species: Tanyxiphium seychellense Huber, 2015, by original designation. Diagnosis. Tanyxiphium is distinguished from the other genera of Gonatocerini by the following combination: mandible small, shorter than maxilla, with teeth minute (Fig. 321a); pronotum short, entire or apparently so (Fig. 324); dorsellum rhomboidal; ovipositor extending beyond gaster (Fig. 325a). Male head wider (Fig. 326a,b) and relatively narrower than in female (Fig. 321a,b); mandibles large, crossing when closed, each with 3 normal teeth (Fig. 326a); pronotum longer than in female, with lateral lobes apparently widely separated due to different colour of median area (Fig. 328). Remarks. Tanyxiphium belongs to the Gonatocerus group of genera, treated formally as Gonatocerini in Huber (2015a). Tanyxiphium is the only genus of Gonatocerini that shows secondary sexual differences in structure of the head and mouthparts. Tanyxiphium is most similar to Gonatocerus but differs by the mandibles being sexually dimorphic (not so in Gonatocerus), the vertex with 4 setae between the lateral ocelli (2 in Gonatocerus), and the pronotum entire, though appearing divided, with widely separated lateral lobes (medially divided, with lateral lobes abutting at least ventrally in Gonatocerus). It also is similar to Lymaenon, which sometimes has the vertex with 4 setae between lateral ocelli, pronotum with widely separated lateral lobes though in Lymaenon the pronotum really is divided whereas in Tanyxiphium it appears to be entire because its posterior margin does not have any breaks. Neotropical hosts. Unknown. Important reference. Huber (2015a).