Nenema virgata (Doering, 1941)

Figs 16–17, 26G

Aphelonema virgata Doering, 1941: 206, pl. XIII: fig. 4, pl. XIV: figs 16, 21, pl. XV: figs 11, 22.

Aphelonema (Nenema) virgata – Emeljanov 1996: 834 (proposed new subgenus of Aphelonema). Nenema virgata – Gnezdilov 2013: 212.

Diagnosis

Body mainly black and pale-yellow, with central plate of frons white and sublateral carinae black, forewing dark brown to black with oblique white stripe over claval suture, abdomen almost black, with broad pale-yellow median longitudinal stripe dorsally and narrower discontinuous white to paleyellow longitudinal stripes laterally, legs reddish brown (Fig. 16); clypeus swollen (Fig. 16A, C), with weak carina incomplete ventrally (Fig. 16A); abdominal tergites (Figs 16C, 26G) with one sensory pit followed by single isolated ventral sensory pit (tergite IV and V) or isolated pair of diagonally aligned ventral sensory pits (tergites VI to VII).

Material examined

MEXICO • 1 ♀; “COAH” [Coahuila de Zaragoza], Cuahtemoc rd., Km 7.4; 25.27970° N, 100.98747° W; 2120 m a.s.l.; Oct. 2005; C. Dietrich leg.; vacuum sample; INHS • 1 ♀; same collection data as for preceding; DNA voucher ENT4919; DZRJ .

Description

BODY LENGTH. Females = 3.3 to 3.5 mm.

COLORATION. Body mainly black and pale-yellow (Fig. 16 A–C). Central plate of frons (Fig. 16A) white, sublateral carinae black and side of frons pale-yellow in frontal view. Clypeus mainly black, with dorsal portion pale-yellow (Fig. 16A). Vertex (Fig. 16B) white to pale-yellow with two pairs of brown maculae; pronotum and mesonotum (Fig. 16B) with pale-yellow continuous median longitudinal broad stripe. Gena (Fig. 16C) pale-yellow; with oblique black stripe starting at ventral margin of eyes, reaching clypeus and drop-like black macula near anteroventral margin of eye. Lateral lobe of pronotum (Fig. 16C) with anterior portion black and posterior portion pale-yellow continuous to forewing stripe. Forewing (Fig. 16 B–C) dark brown to black, with oblique white stripe over claval suture. Abdomen (Fig. 16 B–C) dark brown, almost black, with broad pale-yellow median longitudinal stripe dorsally and narrower discontinuous white to pale-yellow longitudinal stripes laterally. Legs (Fig. 16A, C) reddish brown.

HEAD AND THORAX. Vertex (Fig. 16B) hexagonal, as long as half its width, as long as pronotum; posterior margin slightly elevated. Frons (Fig. 16A) with weak median carina and pair of sublateral carinae; sublateral carinae reaching clypeus ventrally (Fig. 16A); central plate (Fig. 16A) longer than wide at widest portion, not visible in dorsal view (Fig. 16B), not extending anteriorly beyond sublateral carinae in lateral view (Fig. 16C); sides of frons partially visible in frontal view (Fig. 16A), not fused above clypeus, with two rows of sensory pits on each side in lateral view (Fig. 16C): anterior row with eight sensory pits, two ventral ones slightly displaced; posterior row with four sensory pits, ventral one slightly isolated. Clypeus (Fig. 16C) swollen, with weak carina incomplete ventrally. Ocelli absent. Eye oblong. Antenna short, with several small circular structures visible on pedicel. Pronotum (Fig. 16B) semicircular, shorter than half its width, without median carina; median portion of disc without sensory pits and with posterior portion slightly elevated; lateral portion of disc with 15 to 17 sensory pits; lateral lobe of pronotum (Fig. 16C) with one sensory pit. Mesonotum (Fig. 16B) without median carina and with pair of lateral carinae; region between lateral carinae depressed, without sensory pits; region laterad of lateral carina with 14 sensory pits. Brachypterous, with reduced venation. Legs simple, with carinae and setae; tibia III with single median spine.

ABDOMEN. Terga without longitudinal carinae. Tergite III (Figs 16C, 26G) without sensory pits. Tergites IV and V (Figs 16C, 26G) with one sensory pit followed by single isolated ventral one. Tergites VI and VII (Figs 16C, 26G) with one sensory pit followed by isolated ventral pair aligned diagonally. Tergite VIII with one sensory pit.

FEMALE TERMINALIA. Posterior margin of sternite VII (Fig. 17B) with sub-rectangular median projection; lateral portions concave; setose. Gonoplac (Fig. 17C) sclerotized, sub-rectangular with apex convex; setose. Anterior connective lamina of gonapophysis VIII (Fig. 17D) with three apical teeth: all subequal, two outermost closer to each other than to inner one. Posterior connective lamina of gonapophysis IX (Fig. 17 E–F) distal part in lateral view (Fig. 17F) with longitudinal row of six wide triangular spines; spines extending anteriorly to stem (Fig. 17F); middle portion with several pits (Fig. 17F); apex setose (Fig. 17F). Segment X of anal tube (Fig. 17 G–H) longer than wide at widest portion; caudal margin (Fig. 17G) pointed with apex rounded; setose.

Remarks

This species was originally placed in Aphelonema and later transferred to Nenema by Emeljanov (1996). This species has all the diagnostic combination of characteristics of this genus (see Discussion), so we are following Emeljanov’s allocation. The original description and illustrations of the dorsal view of the body and lateral view of the head by Doering (1941) suffice to identify this species. Unfortunately, we could not redescribe male terminalia of this species due to lack of male specimens. The original description does not include information about abdominal sensory pits or female terminalia. As indicated by Doering (1941), this species is similar to Nenema bivittata (Ball, 1902), Nenema confragosa (Doering, 1941) and Nenema convergens (Bunn, 1930) and can be distinguished from these species by the pattern of coloration (Doering 1941).