Psyllaephagus alexion Noyes & Hanson, 1996

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 : 599

Psyllaephagus alexion Noyes & Hanson

(Figs 4,5,1587-1590; Hab. E 237)

Psyllaephagus alexion Noyes & Hanson, 1996 :127,136-137. Holotype E, Costa Rica, NHMUK, examined.

Female (length about 1.5-1.6mm): head black with a very dull, mixed, dark, metallic green and coppery purple sheen, mesoscutum more shiny, predominantly coppery purple with some blue-green reflections; scutellum with a relatively strong blue-green sheen with some coppery purple reflections; antenna (Fig. 1587) scape dark brown, flagellum brown; tegula dark brown; femora dark brown; tibiae yellow, each with a faint pale brown, subbasal spot; head (Fig. 1589) about 3.1X as wide as mouth opening; frontovertex about 0.4X head width and 3.1X as wide as mouth opening, with shallow piliferous punctures, each a little larger than eye facet but somewhat obscured by the coarse, relatively deep, polygonally reticulate sculpture; ocelli forming an angle of about 95°, posterior ocellus about equidistant from eye and occipital margins; scrobes shallow, separated from anterior ocellus by about 2X length of torulus; antenna (Fig. 1587) with scape about 4.3X as long as broad and very slightly longer than width of frontovertex; pedicel slightly longer than F1; all funicle segments longer than broad, linear sensilla on all segments or absent from F1; clava with segments becoming gradually shorter towards apex which is more or less rounded; clypeal slightly convex, protuberant; mandible with one tooth and a broad truncation; mesoscutum with slightly shallower sculpture than that on scutellum; scutellum slightly convex; fore wing ( Fig. 5) about 2.4X as long as broad, marginal vein ( Fig. 4) more or less punctiform; costal cell with only a single line of setae dorsally, linea calva closed; T3 of gaster without a distinct, strongly reticulate area anteromedially; ovipositor longer than mid tibia and hidden, second valvifer with about 10 subapical setae. Male: unknown.

DISTRIBUTION. Costa Rica ( Noyes & Hanson, 1996).

HOSTS. Unknown.

MATERIAL EXAMINED.

Type material. HolotypeE: COSTA RICA, Puntarenas, R.F. Golfo Dulce, 24km W Piedras Blancas , 200m, 11.v.1991 (P. Hanson). Paratypes: COSTA RICA, 1E, Alajuela, Peñas Blancas, 23.v.1987 (E. Cruz). Material in NHMUK .

Non type material. COSTA RICA, 1E, Puntarenas, PN Corcovado, Los Patos , 8°33’N 83°30’W, 200m, MT/YPT, ii.2000 (J.S. Noyes, J. Azofeifa). Material in MZUCR .

COMMENTS. Psyllaephagus alexion and thonis are very close and were once thought to represent varieties of the same species. However, in alexion the sensory part of the clava is shorter than the combined ventral lengths of the first two segments, the ocelli form an angle of about 90°, and the sculpture of the frontovertex below the anterior ocellus and on the mesoscutum is relatively shallower. In thonis the sensory part of the clava is longer than the combined ventral lengths of its first two segments, the ocelli form a distinctly obtuse angle and the sculpture of the frontovertex below the anterior ocellus and on the mesoscutum is relatively coarse. Psyllaephagus alexion is also similar to ufens but females of alexion differ from those of the other two species in having the scape a little longer than the minimum frontovertex width, all funicle segments at least slightly longer than broad and the mesoscutum slightly more shiny than the scutellum, whereas in thonis and ufens the scape is a little shorter than the frontovertex width at least F6 is transverse and the mesoscutum is about as dull as, or duller than, the scutellum. See also comments under ufens (p. 583) and thonis (p. 598).

There is also some similarity between alexion and baccharidis Tavares and Perioto described from southern Brazil. The species have a similar habitus and leg colouration. Psyllaephagus baccharidis differs in being generally brighter in colouration, the head and dorsum of the thorax being bright metallic green whereas in alexion these parts are relatively dull. Also, in baccharidis , the scutellum is similar in colouration and sculpture to the mesoscutum whilst in alexion the scutellum is significantly brighter and with deeper sculpture than the mesoscutum. The frontovertex of baccharidis also has no distinct piliferous punctures and the posterior ocellus is clearly closer to the eye margin than occipital margin, whilst in alexion the frontovertex has shallow, but conspicuous piliferous punctures and the posterior ocellus is about equidistant from the eye and occipital margin.