Hebynthus, 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 : 682-683

Genus HEBYNTHUS gen.nov.

Type species: Hebynthus solex sp.nov. Gender masculine.

Female. Length about 1.1-2.5mm.

Body robust, generally dark with a weak to moderate metallic sheen; flagellum variable, usually unicolourous dark brown, sometimes paler or bicoloured; palpi white or dark brown; dorsum of thorax with dark setae; tegula dark brown; wings hyaline with a small infuscate area below marginal vein, sometimes apical one-third may be weakly infuscate or the whole wing may be generally infused yellow-brown or very pale brown, venation pale orange, sometimes with apical parts of venation brown, occasionally completely pale orange or very rarely brown; propodeum dark with a weak metallic sheen, side more strongly metallic, some silvery setae near spiracle; gaster dark with a metallic sheen.

Head in profile about 1.7-2.3X as high as deep, anteriorly fairly evenly curved from occipital margin to top of scrobes, then usually forming a slight angle towards mouth margin, sometimes evenly curved from occipital margin to mouth margin, interantennal prominence slightly to clearly protuberant; occipital margin sharp, carinate; frontovertex about 0.15-0.35X head width and with fairly regular, polygonally reticulate sculpture and sparse, shallow piliferous punctures, usually 2-6 setae medially between anterior ocellus and top of scrobes; ocelli forming an angle of about 70-95°; temple and gena with shallow, longitudinally elongate, polygonally reticulate to striate-reticulate sculpture; eye almost always reaching or overreaching occipital margin, naked or conspicuously hairy; scrobes shallow, ∩-shaped, weakly margined dorsally and laterally; antenna attached below lower eye margin, varying from hardly above mouth margin to hardly below lower eye margin; scape about 4.0-7.2X as long as broad, about 0.4-0.6X as long as head width; funicle segments varying from all transverse to mostly longer than broad, segments gradually becoming larger and broader distally, linear sensilla on all segments to only on F5-F6; clava from shorter than funicle to slightly longer, 3-segmented, sutures strongly oblique, sensory area enlarged, extending 0.4-0.7X along ventral surface giving apex a distinct, obliquely truncate appearance; malar sulcus absent or present, distinct; mouth about 0.35-0.4X head width, clypeal margin weakly emarginate, rarely with a weak median lobe; mandible tridentate, upper tooth truncate or rarely rounded; 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 convex, dorsally with polygonally reticulate to striate-reticulate sculpture that is much deeper than sculpture on mesoscutum, side and apex completely smooth and shiny, apex forming a distinct angle, often nearly 90°, with dorsal flat part; mid tibial spur about as long as basitarsus, sometimes distinctly longer; fore wing fully developed, about 2.2-2.8X as long as broad; costal cell mostly with only 1 complete line of setae ventrally, rarely with 2; submarginal vein with an apical hyaline break; marginal vein about 4.7-8.8X as long as broad, about 1.4-2.1X as long as stigmal vein and about 1.3-2X as long as postmarginal vein, stigmal vein about as long as postmarginal vein; linea calva open or partially closed; filum spinosum present, consisting of a line of about 2-4 stouter setae; posterior margin of mesopleuron varying from falling well short of reaching level with posterior margin of propodeum by about 2X diameter of spiracle to about reaching level, but never extending past posterior margin of propodeum; propodeum fairly short, medially with irregular sculpture, side without a carina posteriorly above hind coxa, sometimes with a short angular tooth posterolaterally behind spiracle; about 10-30 setae near spiracle, sometimes extending towards hind coxa.

Gaster with hypopygium not reaching apex; paratergites absent; syntergum shorter than mid tibia, apex acute to narrowly truncate; ovipositor exserted, the exserted part about 0.2-0.8X as long as mid tibial spur; ovipositor slightly longer than mid tibia, second valvifer with no subapical seta or with a single seta, proximal part broadly C-shaped; hypopygium W-shaped, mid anterior process short, lateral arms short to moderately long without a shallow notch on external margin, posterior margin with a shallow invagination.

Male. Length about 0.9-1.4mm.

Generally very similar to female but for slightly wider frontovertex, higher placement of antenna and structure of antenna and genitalia. Frontovertex about 0.25-0.4X head width; antennal torulus about level with lower eye margin; scape about 3.3-4.0X as long as broad; flagellum filiform, all funicle segments about 1.5-2X as long as broad and clothed with setae that are about as long as diameter of segments; phallobase with moderately long digiti, each about 1.9-2.4X as long as broad with a single apical tooth; aedeagus about 0.4-0.5X as long as mid tibia with apex acute.

DISTRIBUTION. Known only from Trinidad & Tobago and Costa Rica, but likely to be more widespread in the Neotropics.

HOSTS. One species has been reared from mealybugs ( Hemiptera : Pseudococcidae ). It is not known whether it is a primary parasitoid or hyperparasitoid.

COMMENTS. Hebynthus may be close to Dalek and possibly also Caldencyrtus and similar genera (e.g. Alkonia , Raquanus , Mendisa , etc.) that may form a monophyletic group (see comments under Alkonia , p. 708). Females of Hebynthus can be separated from those of Dalek and the other genera of this group by the combination of having a strong oblique apical truncation on the clava that extends at least one-third along its ventral surface, the clava not as long as the pedicel and funicle combined and the scape at least 4X as long as broad. Females of Hebynthus have the frontovertex less than 0.35X head width and the mouth less than 0.4X head width, whilst in Dalek the frontovertex is 0.4-0.5X head width and the mouth is more than 0.4X head width. In addition, females of Hebynthus usually have the ocelli forming an angle of less than 90°, the eye reaching the occipital margin, the mouth margin emarginate without a convex median lobe, often at least one funicle segment transverse and the fore wing venation almost always yellow or orange. Females of Dalek have the ocelli virtually always forming an angle of much more than 90°, the eye never quite reaches the occipital margin, the mouth margin often has a convex median lobe, the funicle segments are usually all longer than broad, with only F6 occasionally quadrate and the fore wing venation is always brown. Finally, in Hebynthus the anterior lateral arms of the hypopygium do not have a shallow notch on their outer margin about halfway along their lengths whilst in Dalek the anterior arms of the hypopygium have an elongate, shallow notch on their outer margin about half way along their lengths.

Hebynthus is close to Syrphophagus , species of both genera having a tridentate mandible with the upper tooth truncate, sharp occipital margin and obliquely truncate clava. Hebynthus can be separated from Syrphophagus by having deep, coarse, cellular or striate sculpture on the scutellum that contrasts strongly with the shallow imbricate-reticulate or polygonally reticulate sculpture on the mesoscutum. In Syrphophagus , the sculpture on the scutellum is usually similar to that on the mesoscutum, but if slightly deeper it is and polygonally reticulate. In addition, the scutellum in Hebynthus is quite strongly convex with the posterior one-third, in profile, often forming a distinct angle with the anterior two-thirds and the apex is conspicuously more shiny, often completely smooth and mirror shiny, whereas in Syrphophagus the scutellum is flat to moderately and more or less evenly convex with the sculpture reaching the apex.

See also comments under Prionias (p. 169).