Contarinia dichanthiumae, Siddiqui & Najam & Deshpande, 2010

Siddiqui, M. S., Najam, K. A. A. & Deshpande, V. D., 2010, Two new Indian gall midges of the genus Contarinia Rondani (Cecidomyiidae: Diptera) reared from Amaranthaceae & Poaceae, Journal of Threatened Taxa 2 (3), pp. 773-777 : 775-776

Contarinia dichanthiumae , sp. nov.

( Figs.17-32 )

Material examined

Holotype: Male, 12.xii.2005, (Slide no. Cont. 4), labelled as, “reared from ear heads of Dichanthium aristatum Hub. (Family Poaceae ), Vishnupuri, Nanded District, India, coll. M.S. Siddiqui.

Allotype: One female (Slide no. Cont.5), data as of Holotype.

Paratype: Two males (Slide no. Cont.6-7), and two females (Slide no. Cont.8-9), data as of Holotype.

Study area: Vishnupuri, Nanded District, Maharashtra, India.

Etymology

The specific epithet dichanthiumae is associated with the host grass species i.e. Dichanthium aristatum Hub. (Family: Poaceae ).

Diagnostic features

Male

Body: 1.33mm long.

Head: eyes confluent above. Trophi normal. Palpus ( Fig. 22 ) quadriarticulate, short, first segment (5:4) subglobose, second segment (9:6) subcylindrical, third segment (8:5) subcylindrical, fourth segment (8:4) subcylindrical, 2.00x as long as thick.

Antenna: 1.00mm long, shorter than the body, with 2+12 segments, flagellate segments binodose, basal enlargements subglobose, with one whorl of long, regular circumfila and one whorl of long bristles, apical enlargements subglobose, with one whorl of long, regular circumfila and one whorl of long bristles; scape ( Fig. 21a ) (9:14) cup-shaped; pedicel ( Fig. 21b ) (10:11) subglobose; third segment ( Fig. 19a ) (30) confluent with and longer than the fourth, with a very short basal prolongation (3:4), basal enlargement (9:8) 1.12x as long as thick, basal stem (4:5) nearly half the basal enlargement and thicker than long, apical enlargement (10:10) slightly longer than the basal, apical stem (4:5) less than half the length of apical enlargement, thicker than long, fourth segment ( Fig. 19b ) (27) shorter than thick, with basal enlargement (8:9) 0.88x as long as thick, basal stem (3:4) less than half the basal enlargement and thicker than long, apical enlargement (11:10) longer than the basal, apical stem (4:4) less than half the length of apical enlargement and as long as thick; fifth segment ( Fig. 20 ) (28) with a basal enlargement (7:9) one fourth the length of segment, thicker than long, basal stem (5:5) nearly two-third the length of basal enlargement, apical enlargement (11:10) longer than the basal, 1.57x the length of the basal enlargement, apical stem (5:4) nearly half the length of apical enlargement; sixth to twelfth segments progressively shortened distally; penultimate segment ( Fig. 17a ) (22) with the basal enlargement (7:7) 0.31 the length of the segment, basal stem (3:3) nearly half the length of basal enlargement, apical enlargement (8:7) longer than the basal, 1.14x as long as thick, apical stem (5:3) more than half the length of apical enlargement and 1.66x as long as thick; terminal segment ( Fig. 17b ) (20) shortest of all, with basal enlargement (6:6) 0.3 the length of the segment, basal stem (3:2) 0.5 the length of basal enlargement, apical enlargement (8:6) longer than the basal, ending with a rounded tip.

Thorax: Mesonotum pale brown. Wing ( Fig. 24 ) (95:35) hyaline, 2.7x as long as broad, vein Rs short, Vein R 5 reaching wing margin at the wing apex and interrupting costa at its union; vein Cu simple.

Legs: long, densely hairy, metatarsus (21) longer than terminal tarsal segment (20), second tarsal segment (72) longest of all. Claw ( Fig. 23 ) (10) simple on all legs,

17(a,b) - Penultimate and terminal antennal segments; 18 - Genitalia 19(a,b) - Third and fourth antennal segments; 20 - Fifth antennal segment; 21(a,b) - Scape and pedicel; 22 - Palpus; 23 - Claw; 24 - Wing; 25 - Palpus; 26 - Claw; 27(a,b) - Scape and pedicel; 28(a,b) - Third and fourth antennal segments; 29 - Fifth antennal segment; 30(a,b) - Penultimate and terminal antennal segments; 31 - Ovipositor 32 -Wing.

sickle shaped, empodium (8) 0.8 the length of the claw. Genitalia ( Fig.18 ) basal clasp segment (30:21) oval, 1.42x as long as broad; terminal clasp segment (22:6), 3.7x as long as broad, ending with a pointed tooth apically; dorsal plate (15:13) deeply bilobed, lobes round, subdorsal plate (12:14) bilobed, shorter and wider than the dorsal plate, lobes broadly rounded apically, aedeagus (12) as long as the subdorsal plate but shorter than the dorsal plate.

Female

Body: 2.50mm long.

Head: Eyes confluent above. Trophy normal. Palpus ( Fig. 25 ) quadriarticulate, moderately hairy, first segment (11:5) subcylindrical, second segment (10:5) subcylindrical, third segment (9:5) subcylindrical, fourth segment (11:4) cylindrical, as long as first.

Antenna: 0.90mm long, shorter than the body, with 2+12 segments, flagellate segments cylindrical, enlargements with low circumfila, and with two whorls of long bristles; scape ( Fig. 27a ) (10:18) cup-shaped; pedicel ( Fig. 27b ) (11:12) subglobose; third segment ( Fig. 28a ) (22) confluent with but nearly as long as the fourth, with a short basal prolongation (3:2), enlargement (16:9) 1.8x as long as thick, apical stem (3:3) 0.18 the length of the enlargement, fourth segment ( Fig. 28b ) (21) with enlargement (18:9) 0.85 the length of the segment, apical stem (3:3) 0.16 the length of the enlargement, fifth segment ( Fig. 29 ) (22) with enlargement (18:8) 0.81 the length of the segment, and 2.25x as long as thick, apical stem (4:4) 0.2 the length of the enlargement; Sixth to twelfth segments progressively shortened distally; penultimate segment ( Fig. 30a ) (15) with enlargement (13:6) 0.86 the length of the segment, apical stem (2:2) 0.15 the length of the enlargement, Terminal segment ( Fig. 30b ) (16) with enlargement (14:6) 0.86 the length of the segment, tip rounded apically.

Thorax: Mesonotum pale brown. Wing ( Fig. 32 ) (94:39) hyaline, 2.41x as long as broad; venation as in male.

Legs: brown, long, densely hairy, metatarsus (20) as long as the terminal tarsal segment, second tarsal segment (80), third segment (36) longer than the fourth (22); Claw ( Fig. 26 ) (13) simple on all legs, sickle shaped; empodium (9) 0.69 the length of claw. Ovipositor: ( Fig. 31 ) aciculate, exserted, needle like, shorter than the body.

Remarks

Contarinia dichanthiumae sp. nov. is morphologically closer to C. prosopidis (Mani, 1938) , but can be easily distinguished in possessing (i) empodium shorter than claw (not, empodium longer than claw), (ii) enlargement of fifth antennal segment of female 2.25x as long as thick (not 1.5x as long as thick). This new species can also be easily separated from other closely related species i.e. C. caudata ( Felt, 1920) in possessing empodium shorter than claw (not, empodium as long as claw) and C. orientalis ( Rao & Sharma, 1977) infesting ear heads of Dichanthium pertusum (L.) W.D. Clayton, in having quadriarticulate palpi (not, triarticulate).

Figures

Figures 17-32. Contarinia dichanthiumae sp. nov. (17-24 male; 25-32 female)