Dacus (Mellesis) jacobi David & Sachin, 2020

David, K. J., Sachin, K. & Hancock, D. L., 2020, Two New Species And A New Record Of Dacus Fabricius (Diptera: Tephritidae) From India, Zootaxa 4743 (4), pp. 553-560 : 555-556

Dacus (Mellesis) jacobi David & Sachin , sp. n. ( Figures 1‒8 )

Description: Male

Head: Frons light fuscous with two frontal setae and single orbital seta, ocellar triangle and ocelli black, medial and lateral vertical setae present. Occiput black with a row of thin black postocular setae. Face reddish brown with inverted U-shaped black marking. Gena fulvous with subocular spot and without seta. Scape elongate, fulvous, pedicel and first flagellomere dark brownish; combined length of pedicel and first flagellomere longer than vertical length of face.

Thorax: Scutum reddish brown without medial and lateral postsutural yellow vittae. Yellow markings as follows; notopleuron, base of transverse suture, narrow anipesternal stripe as broad as notopleuron and 0.5 dorsal of katatergite. Anatergite entirely dark brown, subscutellum black. Scutellum yellow with broad reddish brown basal band covering basal quarter. Chaetotaxy: 1 scapular seta, 1 anterior notopleural seta, 1 posterior notopleural seta, 1 postsutural supra-alar seta, 1 anepisternal seta, 1 post-alar seta, 1 intra-alar seta and 1 scutellar seta.

Legs: Coxa, trochanter, femur, tibia dark fuscous; tarsal segments fulvous.

Wing: (5.81−6.20 mm) dimidiate with broad costal band from cell bc to wing apex, overlapping vein R 4+5 throughout its entire length but not reaching middle of cell r 4+5 apically, anal streak absent.

Abdomen: Elongate and petiolate, tergites reddish brown; tergite I with single fulvous band apically, tergites II and III predominantly black with apical reddish brown areas, tergite III black basally and laterally, but with broad reddish-brown areas medially, tergite IV dark brown or black. Pecten present on tergite III; sternite V with shallow/ flat posterior emargination.

Male genitalia: Epandrium strongly sclerotised, longer and broader than length of lateral surstylus; posterior lobe of lateral surstylus elongate, 7‒8 times longer than anterior lobe. Proctiger membraneous, round and smaller than epan- drium. Epandrium and surstyli distinctly bulb-shaped in posterior view; medial surstylus shorter than lateral surstylus, tapering towards apex with a pair of thick prensisetae. Phallus elongate (3.36 mm) with well developed sclerotised glans (0.8 mm); 0.75 of glans sclerotised with patterned praeputium; subapical lobe and basal lobe present.

Attractant: Zingerone

Material examined: Holotype, ♂, INDIA: Kerala, Thrissur, KFRI, Peechi , 30.ix.2019, Sachin, K., Paratypes , 2♂♂, India, Kerala, Calicut, Calicut University Campus , 03.x.2019, Sachin, K ., 1♂, INDIA: Kerala, Calicut, Janaki- kadu, 03. x.2019, Sachin, K ( NBAIR) .

Etymology: This species is named after the late D. Jacob, in memory of the first author’s father.

Remarks: D. jacobi , sp. n., is similar to D. vijayasegarani Drew & Hancock and D. siamensis Drew & Hancock in possessing a broad costal band overlapping vein R 4+5, petiolate abdomen and face with inverted U-shaped marking joined with broad band above oral margin. It can be differentiated from D. vijayasegarani and D. siamensis by the paler reddish brown scutum and abdomen and the broad reddish brown basal band covering basal quarter of the scutellum; it further differs from D. vijayasegarani by its yellow notopleuron, and from D. siamensis by its moderately developed posterior lobe of the lateral surstylus. It differs from the otherwise similar Sri Lankan species D. ancoralis Leblanc & Doorenweerd ( Leblanc et al. 2018) in characters noted in the key.

Figures

FIGURES 1-8. Dacus (Mellesis) jacobi David & Sachin, sp. n. 1, head; 2, scutum (dorsal view); 3, thorax (lateral view) and legs; 4, abdomen; 5, wing; 6, epandrium and surstyli (lateral view); 7, epandrium and surstyli (posterior view); 8, glans of phallus.