Prionias, Noyes, 2023

Noyes, John Stuart, 2023, ENCYRTIDAE OF COSTA RICA (HYMENOPTERA: CHALCIDOIDEA), 4 Subfamily Encyrtinae: tribes Arrhenophagini, Habrolepidini, Cerapterocerini, Cheiloneurini, Trechnitini, Cercobelini, Polaszekiini, Protyndarichoidini, Gahaniellini and Syrphophagini (part), mainly primary parasitoids and hyperparasitoids of Coccoidea and Psylloidea (Hemiptera), Taxonomic Monographs on Neotropical Hymenoptera (Oxford, England) 2 (11), pp. 1-921 : 168-169

Genus PRIONIAS gen.nov.

Type species: Prionias nodutus sp.nov. Gender masculine.

Female. Length about 1.7mm.

Body slender, generally dark with a weak to moderate metallic sheen; scape and funicle orange, contrasting with brown clava; palpi off-white; dorsum of thorax with dark setae; tegula dark brown; legs mainly pale yellow to pale orange with some dark areas; wings hyaline, venation pale brown; propodeum dark with a weak metallic sheen, side strongly metallic, a few silvery setae near spiracle; gaster dark with a metallic sheen.

Head in profile about 1.6X as high as deep, anteriorly fairly evenly curved from occipital margin to top of scrobes, more strongly curved or angled at top of scrobes and virtually straight to mouth margin, interantennal prominence slightly protuberant; occipital margin sharp, weakly carinate; frontovertex about one-fifth head width, slightly shiny, with polygonally reticulate sculpture; a very short, longitudinally orientated, shiny-bottomed groove present adjacent to eye margin between each posterior ocellus and occipital margin; ocelli forming an acute angle; eye slightly overreaching occipital margin, clothed with sparse, inconspicuous setae that are slightly shorter than diameter of facet; scrobes shallow, ∩-shaped, weakly margined dorsally and laterally; antenna attached about midway between lower eye margin and mouth, dorsal margin of torulus slightly below lower eye margin; scape subcylindrical. about 5X as long as broad; all funicle segments longer than broad, subequal in length, becoming slightly broader distally, linear sensilla conspicuous and on all segments except F1; clava shorter than funicle, 3-segmented, outer suture slightly oblique, sensory area enlarged, extending a little way along ventral margin of clava, apex distinctly obliquely truncate; malar sulcus absent; mandible tridentate, upper tooth broadly truncate; palp formula 4-3.

Thorax with pronotum short, its posterior margin distinctly concave; mesoscutum without notaular lines, with polygonally reticulate to imbricate-reticulate sculpture; scutellum flat with fairly regular, polygonally reticulate sculpture that is arranged in whorls and conspicuously deeper than sculpture on mesoscutum or axillae, extreme apex and side completely smooth and shiny, a pair of long subapical setae present, each about half as long as scutellum; mid tibial spur about as long as basitarsus; fore wing fully developed; about 2.6X as long as broad; costal cell with 2 nearly complete lines of setae ventrally and a line of setae dorsally in apical half or so; submarginal vein with an apical hyaline break, parastigma slightly swollen and slightly downwardly curved; marginal vein about 8X as long as broad, about 2X as long as stigmal vein or postmarginal vein; linea calva open; filum spinosum present, consisting of a line of about 4 or 5 stouter setae; posterior margin of mesopleuron reaching level with posterior margin of propodeum; propodeum fairly short, medially with a single median carina; about 10 setae near spiracle.

Gaster with hypopygium not quite reaching apex; paratergites absent; syntergum shorter than mid tibia, apex with a narrow, tongue-like projection; ovipositor slightly exserted; ovipositor longer than mid tibia, second valvifer without subapical setae, proximal part narrowly C-shaped; hypopygium elongate, V-shaped, very clearly as long as broad, mid anterior process long and slender, lateral arms long, each with a shallow but distinct notch on external margin, posterior margin elongate and acute with a shallow median invagination.

Male. Unknown.

DISTRIBUTION. Known only from Costa Rica.

HOSTS. Unknown.

COMMENTS. The sharp occipital margin, tridentate mandible with two acute lower teeth and a distinctly truncate upper tooth, obliquely truncate clava, relatively deep sculpture of the scutellum and elongate marginal vein of the fore wing suggest that Prionias may be related to Hebynthus . Prionias can be distinguished from Hebynthus and related genera by the presence of the slightly downwardly curved parastigma and the prominent tongue-like apical projection on the syntergum. The funicle and clava are also relatively slender compared to most species of Hebynthus and the sensory area is also relatively short, extending only about one-third along the ventral surface of the clava. In Hebynthus the sensory area of the clava extends more than one third along its ventral surface. Perhaps the most important difference from genera related to Hebynthus and also to Dalek is the elongate, V-shaped hypopygium which has an acutely extended posterior margin. The other genera have the posterior margin of the hypopygium truncate or more or less square.

The shiny-bottomed grooves behind the posterior ocelli, fore wing with a slightly downcurved parastigma and relatively very elongate marginal vein suggest the possibility that Prionias may be more closely related to Prochiloneurus (Cheiloneurini) because the V-shaped hypopygium is quite similar. However, alongside many other differences between the genera, the hypopygium is even more slender and elongate than in Prochiloneurus and the fore wing is hyaline, the scutellum lacks an apical tuft of setae and the apex of the gaster has a narrow tongue-like extension. In Prochiloneurus the fore wing is always infuscate, the scutellum usually has an apical tuft of setae and the apex of the syntergum is truncate, even slightly concave.

In some respects Prionias is superficially similar to species of Mahencyrtus and perhaps even Comones Noyes & Woolley (both Cheiloneurini ), the latter genus sharing similar fore wing venation to Prionias . However, Prionias can be separated from both of these genera because they have the antenna attached level with the lower eye margin, the apex of the clava rounded, three distinct teeth in the mandibles and the hypopygium strongly transverse (subrectangular).

See also comments under Strigenia (p. 172).