Acrocercops crena, Sruoga & Prins, 2023

Sruoga, Virginijus & Prins, Jurate De, 2023, New species, new country distribution records, and a new generic combination of Afrotropical Acrocercopinae (Lepidoptera: Gracillariidae), Zootaxa 5285 (1), pp. 75-115 : 77-79

Acrocercops crena , sp. n.

( Figs 1A–G ; 2 )

Material examined. Holotype: 1♁, Kenya, Mount Kenya, Chorogia, 1600 m, 00°14’S 37°35’E (M8/08), 13– 14.iv.2001, leg. J. & W. De Prins. Gen. prep. VS564. Wing venation prep. VS568, in coll. RBINS.

Diagnosis. Superficially, Acrocercops crena sp. nov. is similar to many Afrotropical Acrocercopinae species with white transverse fasciae on the forewing. Male genitalia of A. crena sp. nov. are distinctive from all other Afrotropical species currently assigned to Acrocercops by the combination of the following features: valva with a single comb of teeth and a group of stout setae on the inner surface near the apex of valva beyond the comb, aedeagus with a pair of apical teeth laterally and by the dorsal processes of tegumen. Besides this, the male sternite VII is distinguished with a caudal margin widely notched, and with strongly sclerotized delicately dentate short bands just laterad from the margins of the notch.

Description. Adult ( Figs 1A, B ). Forewing length: 3.6 mm.

Head: Frons white with few dark grey scales ventro-laterally; vertex white. Labial palpus about three times as long as width of head, slightly upcurved, white, second palpomere grey-brown laterally and terminal palpomere with a few grey-brown scales medially. Maxillary palpus straight, as long as the width of the head, white intermixed with some dark brown scales. Antenna 1.2× as long as forewing, scape white, weakly suffused with fuscous; flagellum brown grey, weakly annulated by darker scales.

Thorax:White; tegulae ochreous brown at anterior half and white posteriorly.Forewing ochreous brown with two, broad, somewhat triangular white transverse fasciae; beyond second fascia at 2/3 of costa a subapical white spot at 4/5 of forewing with a fine streak of white fringe scales at tornus; small apical spot white; all white marks of forewing edged by 1–2 rows of dark brown scales on both sides; apical fringe white, subapical dorsal fringe ochreous brown, fringe line dark brown. Hindwing brownish grey, its fringe scales somewhat paler. Fore coxa white, with brown-grey basal and apical patches; fore femur brown-grey, fore tibia brown-grey, with white basal patch; tarsomere I white with brown-grey subbasal and subapical patches, tarsomeres II–IV white with brown grey medial patches, tarsomere V ochreous white; mid femur brown-grey, mid tibia brown grey in basal and apical parts, medially white, tarsomere I white with brown-grey subbasal and subapical patches, tarsomeres II–IV white with brown-grey medial patches, tarsomere V ochreous white; hind femur white with small brown-grey basal, medial and apical patches, hind tibia brown-grey with white subbasal and apical patches, tarsomere I white with brown-grey subbasal and subapical patches, tarsomeres II–IV white with brownish grey apical patches, tarsomere V brownish white.

Abdomen: Brownish grey dorsally and white ventrally, sterna with brownish grey anterior margins laterally. Tergite VIII mediobasally with small Y-shaped dorsocephalic apodeme long and apically knobbed. Caudal margin of sternite VII widely notched, with strongly sclerotized delicately dentate short bands just laterad from margins of notch ( Fig. 1H ).

Male genitalia ( Figs 1C–G ). Tegumen oblong with a pointed apex, gradually narrowed from 1/3 of base, 3 pairs of long setae and a pair of bands of short setae arranged on lateroventral edges in basal part; a pair of sclerotized projections of dorsal surface directed centrally and then anteriorly at basal 0.45 length of tegumen ( Figs 1F, G ). Valva about 3/5 as long as tegumen, dilated basally, strongly tapering from about 2/3 towards narrow strongly setose blunt apex; inner surface with one comb placed at basal 3/5, with 29–31 teeth, occupying about 1/4 length of valva, and a group of stout setae beyond comb at apex of valva; long slender androconial scales scattered on outer surface of valva near base; 8–10 long scent scales in a group arising from inner surface of valva at about 1/3 from base, and those from both valvae connected with each other by flattened apical parts in form of oblong leaf at back of tegumen. Vinculum small, with short rounded saccus. Aedeagus slightly shorter than valva, tubular, basally slightly dilated, gradually narrowed apically, apex truncated, with a pair of short teeth laterally; vesica with a band of minute spines nearly 1/3 length of aedeagus, apically mixed with a few larger ones.

Female. Unknown.

Host plant(s). Unknown.

Flight period. The only known specimen was captured at mid-April.

Distribution. Known only from the type locality in central Kenya.

Etymology. The specific name is from the Latin ‘ crena ’ (notch), in reference to the notched caudal margin of sternite VII in the male abdomen.

Remarks. The placement of this species in the genus Acrocercops is tentative. It does not fit completely in the genus, as it has a highly modified abdominal segment VII in the male abdomen. According to the generic diagnosis of Kumata et. al. (1988a) this segment is simple, as in the preceding segments of the abdomen. By this, A. crena sp. nov. has similarity with species of the genus Dialectica , but wing venation ( Fig. 2 ) does not have stalked veins Rs and M1 as in Dialectica . In wing venation A. crena sp. nov. is more close to the pattern of Acrocercops as pointed by Kumata et al. (1988a): “veins R5, M1 and M2 of forewing connate or approximate basally and arising from apex of more or less lanceolate discoidal cell”.

The head of holotype is somewhat abraded, therefore the description of the head is approximate.

Figures

FIGURE 1. Acrocercops crena sp. nov., holotype, male. A, adult, scale bar 1 mm; B, head, frontal view; C, genitalia, general view (aedeagus removed; left bunch of scent scales broken off during preparation); D, aedeagus; E, cornuti; F, tegumen, dorsal view (arrow pointing to dorsal process); G, central part of genitalia, lateral view (arrow pointing to dorsal process of the tegumen); H, caudal part of abdominal pelt, gen. prep. VS564. F, G, in glycerol before permanent mounting in Euparal. Scale bar 0.1 mm.

FIGURE 2. Acrocercops crena sp. nov., holotype, wing venation prep. VS568. Scale bar 1 mm.