Mahencyrtus, Masi, 1917

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 : 157-158

Genus MAHENCYRTUS Masi

Mahencyrtus Masi, 1917:157 . Type species: Mahencyrtus occultans Masi , by monotypy.

Tyndarichoides Mercet, 1921:649 . Type species: Tyndarichoides metallicus Mercet , by monotypy. Synonymy with Mahencyrtus by Noyes & Hayat (1984:294).

Protyndarichus Mercet, 1923:279 . Replacement name for Tyndarichoides Mercet, 1921 nec Girault, 1920.

Female. Overall length about 1.0- 2.1mm.

Body generally dark brown to black with a metallic green or blue-green sheen; scape pale orange; pedicel and flagellum slightly dusky pale orange; legs mainly yellow to pale orange, coxae and hind femur sometimes darkened; fore wing ( Fig. 394) hyaline, frequently with a median, elongate, wedge-shaped, infuscate mark in distal half.

Head in profile, anteriorly quite evenly and strongly curved from occipital margin to top of scrobes, more strongly curved at top of scrobes and from there quite straight to mouth margin, with interantennal prominence hardly protuberant; occipital margin rounded; frontovertex shiny, mainly with shallow, fairly fine, polygonally reticulate sculpture of mesh size generally less than diameter eye facet; piliferous punctures on frontovertex shallow, but 1.5-2X diameter of eye facet; eye hardly overreaching occipital margin, with very inconspicuous pale setae, each much shorter than diameter of facet; lower inner eye margin ( Fig. 392) slightly emarginate, posterior eye margin strongly emarginate. concave; scrobes shallow, ∩-shaped, meeting dorsally, with distinct sculpture, dorsally and lateral margins rounded; interantennal prominence distinct, clearly reaching past toruli, dorsally rounded; antenna attached about level with lower eye margins, middle of torulus about level with lower eye margin, torulus separated from mouth margin by about its own length; antenna with scape hardly broadened about 4-5X as long as broad; funicle segments varying from all slightly longer than broad to some distinctly transverse, becoming slightly wider distad; linear sensilla present only on F4-F6; clava slightly wider than F6, shorter than funicle, three segmented, sensory area small, at apex only giving it a rounded appearance; head about 3-4X as wide as frontovertex; posterior ocellus virtually touching eye, separated from occipital margin by about 2X its own diameter; occipital margin rounded; clypeal margin not emarginate, weakly convex; malar sulcus present and distinct or absent; mandible with 3 acute teeth, without a ventral peg; palp formula 4-3.

Thorax with pronotum moderately long, clearly visible behind head with posterior margin hardly to strongly concave, sometimes hardly visible medially behind head; notaular lines absent; mesoscutum with imbricate to polygonally reticulate sculpture that is about as deep as that on pronotum or axilla; scutellum dorsally weakly convex and with coarse, longitudinally elongate polygonally reticulate to lineolate reticulate sculpture that is much deeper than that on mesoscutum or axilla, apex and side completely smooth and shiny; scutellum apex, in dorsal view, broadly rounded; mid tibial spur as long as basitarsus, or very slightly longer; wings variable in length, fore wing may be strongly abbreviated and hardly reaching posterior margin of first gastral tergite or fully developed and reaching well past apex of gaster; fully developed fore wing about 2.8-3.4X as long as broad, with linea calva entire; basal cell fairly evenly setose; filum spinosum present, with 3-5 peg-like setae; costal cell with a line of setae dorsally in apical half and a line of setae ventrally; submarginal vein with parastigma slightly downcurved, swollen, forming a weak triangular expansion, apex with a hyaline break; marginal vein at least about 4X as long as broad, slightly longer than postmarginal vein and about 2X as long as postmarginal vein; uncus developed and with 3 campaniform sensilla arranged in almost a straight line; posterior margin of mesopleuron almost reaching level with posterior margin of propodeum; propodeum medially about 0.25X as long as scutellum, with some shallow, irregular sculpture medially, including a median carina; about 10-20 silvery setae anterior to and outside spiracle.

Gaster very nearly as long as head and thorax combined; Gt2 anterolaterally with a more strongly reticulate area; syntergum longer than mid tibia, its apex acute; hypopygium reaching about 0.5X along gaster, about 1.5X as broad as long, anteriorly biconcave, with distinct median and anterolateral projections, posteriorly moderately biconvex with a moderate median invagination that is at least 0.2X as deep as hypopygium length; ovipositor at least 1.5X as long as mid tibia, slightly exserted with exserted part at least about one-third as long as mid tibial spur; second valvifer without subapical setae; gonostylus freely articulated with second valvifer, about 0.25-0.35X as long as ovipositor and slightly longer than mid tibial spur.

Male. Overall length about 0.6-1.6mm.

Extremely similar to female, but with fore wing less strongly infuscate, slightly wider frontovertex, structure of antenna and structure of genitalia; fore wing ( Fig. 401) with infuscate streak paler than in female or absent; head about 2X as wide as frontovertex or slightly wider, posterior ocellus a little less than its own diameter from eye margin and a little more than its own diameter from occipital margin; antennal toruli well above lower eye margin, flagellum filiform with all funicle segments at least about 3X as long as broad and clothed with whorls of long setae, the longest of which may be more than 2X as long as diameter of segment; genitalia ( Fig. 402) with a single small, apical hook on digitus, paramere with apical seta, cuspis seta present; aedeagus slender, apically acute, about 0.4-0.6X as long as mid tibia.

DISTRIBUTION. Cosmopolitan, but see Noyes (2019). The genus has not yet been recorded from the Nearctic region but I have examined specimens of Mahencyrtus (possibly comara (Walker)) from Canada and the USA (NHMUK).

HOSTS. Probably a secondary parasitoid ( Trjapitzin (1989). Recorded from various mealybugs ( Hemiptera : Pseudococcidae ) associated with grasses ( Poales : Poaceae ): Antonina phragmitis Borchsenius , Brevennia rehi (Lindinger) , Chaetococcus phragmitis (Marchal) , Heterococcus nudus (Green) , Trionymus copiosus (Borchsenius) , Trionymus dactylis (Green) , Trionymus perrisii (Signoret) and Trionymus radicum (Danzig) (see Noyes, 2019)

COMMENTS. See comments under Georynus (p. 164), Prionias (p. 169) and Strigenia (p. 172).

IDENTIFICATION. 14 species Worldwide: Hayat, 2006 (key to 4 Indian species); Noyes & Hayat, 1984 (list of 3 Indo-Pacific species); Hayat et al., 2014 ( Saudi Arabia, comparison of 5 World species); Trjapitzin, 1989 (key to 2 Palaearctic species); single species treatments: Masi, 1917 ( Seychelles); Noyes, 1979 (West Indies); Hayat, 2010b ( India).