Stethynium, Enock, 1909

Huber, John T., Read, Jennifer D. & Triapitsyn, Serguei V., 2024, Illustrated key to the genera and catalogue of Mymaridae (Hymenoptera) in the Neotropical region, Zootaxa 5557 (1), pp. 1-263 : 101

STETHYNIUM Enock, 1909

( Figs 314–320 )

Stethynium Enock, 1909: 452 . Type species: Stethynium triclavatum Enock, 1909 , by monotypy.

Diagnosis. Face with faint subantennal sulcus ventral to each torulus, a faint median sulcus (visible in micrographs only) extending ventrally from transverse trabecula almost to about dorsal margin of a torulus and toruli about 1.4× or more their own height from transverse trabecula ( Fig. 314a ); mandibles crossing each other when closed, with 4 teeth; clava 3-segmented, with the sutures between them strongly oblique ( Fig. 315 ); frenum medially divided by a longitudinal sulcus and each paramedial plate longer than wide and light coloured ( Fig. 317 ); ovipositor not or only slightly exserted posterior to apex of gaster ( Fig. 318a,b ). Male flagellum 11-segmented, with apical two segments widely joined ( Fig. 319 ) and genitalia complex and somewhat asymmetrical ( Fig. 320b ), unique.

Remarks. Stethynium belongs to the Anagrus group of genera. The combination of 3-segmented clava with oblique sutures between them, longitudinally divided frenum with each paramedial plate longer than wide, ovipositor not exserted either anteriorly ventral to mesosoma or posteriorly beyond apex of gaster distinguishes Stethynium from other genera in the group. Only a single species is known (from Bermuda) so perhaps the genus should actually be excluded from the Neotropical region.

Neotropical hosts. Unknown.

Important reference. Yoshimoto (1990).

Figures

FIGURES 314–316. Stethynium triclavatum Enock, 314a, head, anterior; 314b, head, posterior; 315, antenna; 316, wings. Specimen from USA (Washington).

FIGURES 317, 318. Stethynium triclavatum Enock. 317, mesosoma, dorsal; 318a, metasoma, dorsal; 318b, metasoma, ventral. Specimen from USA (Washington).

FIGURES 319, 320. Stethynium triclavatum Enock, male. 319, antenna; 320a, metasoma, dorsal; 320b, metasoma, lateral. Specimen from USA (Washington).