Dacus (Mellesis) venkateshi Abhishek & David, 2024

Abhishek, Venkateshaiah, David, Karamankodu Jacob, Hancock, David Lawrence, Pradeep, Shivanand, Kalleshwaraswamy, C. M., Sridhara, S. & Satish, K. M., 2024, New Indian species of Dacus Fabricius (Diptera: Tephritidae: Dacinae: Dacini) similar to Dacus crabroniformis (Bezzi), endemic to the Western Ghats and Northeastern Himalayas, Zootaxa 5446 (3), pp. 366-382 : 375-376

Dacus (Mellesis) venkateshi Abhishek & David , sp. nov.

( Figures 56‒65 )

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Description: Male

Head ( Fig. 58 ): Frons 0.63 mm high and 0.55 mm wide, fulvous with two frontal setae and single orbital seta, bases of all setae black, ocellar triangle black, ocellus fuscous, outer vertical seta and medial vertical seta well developed; occiput black except posterior margin of eye and vertex, postocular setae thin, black; face entirely black leaving triangular fulvous markings towards extremes of epistomal margin and sinusoidal fulvous band below antennal socket; lunule fuscous; antennal segments dark fuscous, arista not plumose, antennal segments viz., scape (0.51 mm), pedicel (0.47 mm) and flagellomere is missing in the specimen and the vertical length of face is (1.24 mm).

Thorax ( Figs 59, 60 ): Scutum black without lateral and medial postsutural yellow vittae. Yellow markings as follows: notopleuron, postpronotal lobe, base of transverse suture, anepisternal stripe narrow, slightly broader than notopleuron, continued as yellow spot on katepisternum, 0.6 of katatergite; anatergite black. Scutellum yellow with broad basal black band and a pair of apical scutellar setae. Chaetotaxy, 2 scapular setae, 1 notopleural seta, 1 anepisternal seta, 1 postsutural supra-alar seta,1 post-alar seta, 1 intra-alar seta.

Legs ( Fig. 57 ): Coxa, trochanter, femur of fore and mid legs fully black with completely fulvous tibia, 0.25 of hind femur black apically, hind tibia black; all tarsal segments fuscous.

Wing ( Fig. 62 ): (4.53 mm) predominantly hyaline with broad costal band confluent with vein R 4+5 spilling over to cell r 4+5 at or before the level of end of vein R 2+3, extension of cell cup longer than cup, anal streak present but weak.

Abdomen ( Fig. 61 ): Elongate (2.58 mm long, 1.59 mm wide), petiolate, tergites black in colour; tergite I with single fulvous band transversely, tergites II and III predominantly black with dense hair, tergite IV and V black except for fulvous band between them. Pecten present on tergite III; sternite V with shallow/ flat posterior emargination, all sternites dark brown in colour.

Male genitalia ( Figs 63, 64, 65 ): Epandrium dark brown to black, longer (0.29 mm) and broader (0.30 mm) than length of lateral surstylus; posterior lobe (0.11 mm) of lateral surstylus elongate, 5‒6 times longer than anterior lobe (0.02 mm); anterior lobe of susrtylus with a prominent finger-like projection. Proctiger membraneous (0.07 mm), round and smaller than epandrium. Epandrium and surstyli distinctly oval-shaped in posterior view; medial surstylus (0.02 mm) shorter than lateral surstylus (0.11 mm), tapering towards apex with a pair of thick prensisetae. Phallus elongate (3.76 mm) with well-developed glans (0.51 mm); 0.75 of glans sclerotized with patterned praeputium; subapical lobe and basal lobe present.

Attractant: Zingerone.

Host plant: Not known.

Material examined: Holotype ♂, INDIA: Karnataka, Chikkamagaluru, Etthinabhuja , 14.x.2023, Abhishek, V. ( NIM)

Etymology: This species is named after Mr. Venkatesh, senior author’s father.

Remarks: Dacus venkateshi sp. nov., is similar to D. crabroniformis in possessing broad costal band confluent with vein R 4+5 and in general appearance. It can be differentiated from the latter by the narrow (0.09 mm) yellow marking on transverse suture, wholly black abdomen (abdomen with medial reddish-brown patches on tergites III−V in D. crabronifromis ), broad basal band (0.16 mm) on the scutellum (narrow basal band of 0.09 mm in D. crabroniformis ), dark fuscous lateral surstylus with a prominent finger-like projection in anterior lobe unlike a fulvous/yellow lateral surstylus without finger-like projection in D. crabroniformis , elongate phallus (3.76 mm), twice as long as the phallus of D. crabroniformis (1.5 mm). Moreover, the new species has been collected in Zingerone parapheromone traps from Etthinabuja, Chikkamagaluru, Karnataka (Western Ghats) whereas Dacus crabroniformis have been collected from Bengaluru (Deccan Plateau) and Salem (Eastern Ghats).

Figures

FIGURES 56−57. Dacus venkateshi Abhishek & David, sp.nov. 56, dorsal habitus; 57, lateral habitus.

FIGURES 58−65. Dacus (Mellesis) venkateshi Abhishek & David, sp. nov. 58, head; 59, scutum (dorsal view); 60, thorax (lateral view); 61, abdomen; 62, wing; 63, epandrium and surstyli (lateral view); 64, epandrium and surstyli (posterior view); 65, glans of phallus.