Cheiloneurus diaces, 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 : 403-406

Cheiloneurus diaces sp.nov.

(Figs 1030-1036)

DIAGNOSIS. Female (length about 1.5mm): body mostly orange with some dark brown to black areas with a weak to moderate metallic sheen on head, mesoscutum, and gaster; mouth margin brown, temple and gena with a diagonal, brown streak; antenna (Fig. 1034) with scape mostly pale orange with ventral margin brown; pedicel pale orange with a dark brown longitudinal streak; funicle generally orange to orange-brown, F6 dark brown; clava dark brown; posterior half of mesoscutum with dense silvery setae; fore and mid coxae white, mid coxa pale orange; legs mostly pale orange with distinct brown areas; fore wing (Fig. 1030) mostly infuscate with basal cell almost completely hyaline, a small hyaline area at apex of venation and an opposite hyaline area on posterior wing margin, apex with a large, subtriangular hyaline area; head (Fig. 1035) about 9X as wide as frontovertex, in facial view hardly broader than long, subcircular with genae weakly converging, but slightly more so near mouth margin; frontovertex with one or two setae medially above scrobes; eye separated from scrobe by about 2X diameter of anterior ocellus, area between eye and scrobe completely smooth, scrobal margin sharp; interantennal prominence with about 20 inconspicuous setae and with a distinct median keel dorsally; mandible with three teeth; antenna (Fig. 1034) with scape about 1.9X as long as broad; funicle segments quadrate or transverse; head width slightly less than flagellum length; linear sensilla on F5-F6; clava 3-segmented, about as long as funicle; sensory area large and forming an oblique truncation, extending about 0.5X along ventral margin; mesoscutum (Fig. 1036) anteriorly with fine striate sculpture, posteriorly with relatively shallow, uniform, polygonally reticulate sculpture; scutellum with a distinct apical tuft of setae; wings fully developed; fore wing (Fig. 1030) about 2.5X as long as broad; parastigma clearly downcurved; costal cell more or less naked at apex, with a ventrally line of setae in proximal half; area below proximal part of parastigma with a line of three pale setae; apices of postmarginal and stigmal veins connected by a naked hyaline area that extends as a curved line someway into disc (Fig. 1032); apical bristle of postmarginal vein about 0.8X as long as marginal vein; mid tibial spur slightly longer than basitarsus; propodeum with about six setae adjacent to spiracle, side naked; syntergum about as long as mid tibia; ovipositor (Fig. 1031) about 3.8X gonostylus or 1.5X as long as mid tibia; gonostylus slightly longer than mid tibial spur; exserted part of ovipositor about 0.3X as long as mid tibial spur. Male: unknown.

Female (holotype): length, including ovipositor, 1.52mm; excluding ovipositor, 1.47mm ( CPD) .

Head mostly pale orange to orange-brown; occiput pale orange; frontovertex generally orange-brown, occipital margin pale orange, ocellar area distinctly metallic blue and purple, more anteriorly with only a weak purple sheen and some blue reflections along inner eye margin; temple and gena pale orange with a narrow, oblique brown streak from about mid way along occipital margin towards, but not reaching, torulus; temple and upper gena with a very weak brassy, green and purple sheen; scrobal area and area between eye and scrobe with a very weak brassy and purple sheen, additionally slightly coppery below eye; lower part of gena with very weak purple and brassy reflections; scrobes delimited dorsally by a very weak, narrow, pale brown line that laterally hardly reaches level with torulus; area below toruli with a curved, brown, submarginal line that more or less meets the mouth margin below torulus; frontovertex clothed with inconspicuous, pale brown setae; maxillary palpus white; antenna (Fig. 1034) with radicle pale orange, apex brown; scape mostly pale orange, extreme distal apex white, ventral margin narrowly bordered dark brown nearly to apex, dark margin relatively broad proximally on inner surface; pedicel mostly pale orange with a dark brown streak internally along its length; F1- F4 pale orange-brown, F3-F4 mixed pale orange dorsally, F5 mostly pale orange, mixed brown ventrally, F6 dark brown, clava dark brown, virtually black; pronotum mostly orange, neck broadly brown; pronotum dark brown immediately above coxa; mesoscutum orange in anterior half, posterior half dark brown with a dark metallic blue sheen with purple reflections, paler area clothed in relatively sparse brown setae, darker area clothed in dense, translucent, silvery setae, posterior margin slightly dusky orange with a slight purple sheen; tegula orange with apex dark brown; axilla and scutellum orange, axilla clothed with brown setae, scutellum clothed with translucent pale brown setae, subapical tuft black; metanotum orange; mesopleuron pale orange, slightly dusky posteriorly, anteriorly with a weak brassy and purple sheen, posteriorly with a weak copper, purple and green sheen; fore coxa white; fore femur concolourous with coxa basally, apex pale orange with a pale brown spot on dorsal margin, tibia pale orange with dorsal margin brown subbasally, tarsus orange; mid coxa pale orange; mid leg otherwise coloured similarly to fore leg, except that mid tibia has dorsal margin brown for most of its length and the mid tibial spur and tarsus are pale orange; hind coxa white, femur concolourous at base, but mostly pale orange, dark brown at extreme apex, tibia pale orange with dorsal margin brown subbasally, tarsus orange; fore wing (Fig. 1030) mostly infuscate, hyaline towards base and at apex; submarginal vein pale brown, rest of venation brown; propodeum pale orange-brown, laterally with a weak blue sheen, on sides with a weak purple and blue sheen, some translucent setae near spiracle; gaster dark brown, dorsally with brassy, coppery, purple and green reflections, sides and venter similar, but basal tergite laterally with a distinct metallic, blue-green sheen; outer plates of ovipositor with weak blue, brassy and purple reflections; gonostylus pale orange.

Head (Fig. 1035) nearly 9X as wide as frontovertex, in profile about 1.6X as high as deep, anteriorly quite straight below top of scrobes, interantennal prominence virtually flat level with torulus; occipital margin sharp, not carinate; ocelli forming an angle of about 45°; frontovertex quite shiny, with shallow, fairly regular, polygonally reticulate sculpture of mesh size conspicuously smaller than diameter of eye facet; area between eye and scrobe completely smooth; scrobes shallow, very broadly ∩-shaped, but separated dorsally by a narrow carinate ridge extending medially from interantennal prominence to dorsal scrobal margin which is mostly sharp, scrobe roundly margined laterally and completely smooth; temple and posterior gena virtually smooth, with shallower, more irregular and longitudinally elongate sculpture than on main part of frontovertex, anterior gena with slightly deeper, irregular, reticulate sculpture; antenna as in Fig. 1034; scape broadened and flattened, about 1.9X as long as broad; funicle with F1 quadrate, remaining segments clearly transverse, segments broadest distad, linear sensilla present only on F5-F6; clava strongly broadened, about as long as funicle and pedicel combined, sutures oblique, sensory area enlarged, extending ventrally about 0.5X along clava, giving it an obliquely truncate appearance; eye reaching occipital margin, virtually naked, but clothed in extremely short setae that are conspicuously shorter than diameter of facet; inner eye margins converging strongly below anterior ocellus before diverging above scrobes; malar sulcus more or less absent, but weakly indicated immediately below eye; clypeal margin evenly concave; mandible with 3 teeth, middle tooth longest, upper tooth apically obtuse; apical segment of maxillary palpus not enlarged, about as long as radicle. Relative measurements: HW 66, HH 67, FV 7.5, OD 4.5, POL 4.5, OOL 0, OCL 6, AOL 10, EL 50, EW 34, MS 34, SL 34, SW 17.5.

Thorax (Fig. 1036) with irregular, polygonally reticulate sculpture on pronotum that is similar to that on frontovertex; mesoscutum posteriorly with polygonally reticulate sculpture that is conspicuously deeper and coarser than that on frontovertex, anteriorly in middle with lineolate reticulate sculpture and remainder with very fine longitudinally striate sculpture; axilla and scutellum mostly with fairly regular, polygonally reticulate sculpture, but that on scutellum more longitudinally elongate especially on side where it becomes coarse striate; visible part of mesoscutum about 2.4X as broad as long; scutellum very slightly broader than long with a distinct subapical tuft, setae mostly about 0.5X as long as scutellum; hind femur about 4.5X as long as broad; fore wing with venation and setation as in Figs 1030, 1032; costal cell naked dorsally at apex; apices of postmarginal and stigmal veins connected by a distinct, naked, hyaline streak (Fig. 1032); mid tibia with a distinct longitudinal carina externally for about 0.6X its length; propodeum with a single seta posterior to spiracle and 4 or 5 anterior to it, side completely smooth, medially about 0.17X as long as scutellum and virtually smooth. Relative measurements: FWL 74, FWW 29.5; HWL 57, HWW 15.

Gaster without “gland-like” structures on Gt1 or Gt5; hypopygium (Fig. 1033) reaching about 0.4X to apex; syntergum very nearly as long as mid tibia, with apex acute; ovipositor (Fig. 1031) hardly exserted, the exserted part about one-quarter as long as mid tibial spur or less than 0.1X as long as mid tibia. Relative measurements: OL 54, GL 14 [MT 37].

Variation. Only holotype examined.

Male. Unknown.

DISTRIBUTION. Costa Rica.

HOSTS. Unknown.

MATERIAL EXAMINED.

Type material. Holotype E: COSTA RICA, Guanacaste, Cacao (ACG), 1100 m, MT/YPT, 26.i-24. ii.1996 (J.S. Noyes) . Holotype in NHMUK .

COMMENTS. Cheiloneurus diaces is very similar to letos , both species being generally pale orange in colour with mesoscutum dark posteriorly, and having a relatively narrow frontovertex, a relatively long clava, flattened and broadened scape, and a single line of below the parastigma. The two species can be separated by the relative width of the scape (about 1.9X as long as broad in diaces and 2.4X in letos) and the distribution of setae on the ventral surface of the costal cell of the fore wing (apical two-thirds naked in diaces , a narrowly interrupted line in letos ).

Cheiloneurus diaces is superficially very similar to inimicus Compere (1925) , a hyperparasitoid of soft scales ( Hemiptera : Coccidae ) in the southern USA. The two can immediately be separated because in diaces the top of the scrobes is carinately margined, the clava is very large, longer than the pedicel and funicle combined and the scape is more than 2X as long as wide, whereas in inimicus the top of the scrobes is rounded, the clava is shorter than the funicle and the scape is much more than twice as long as broad.

See also comments under jeroba (p. 410), finator (p. 417) and fautrix (p. 425).