Contarinia manii Harris

Harris, Keith M., 2010, Contarinia manii sp. n. (Diptera, Cecidomyiidae): inducer of a remarkable gall on Acacia ferruginea in southern India, Zootaxa 2423, pp. 63-68 : 64-68

Contarinia manii Harris (new species)

Figures 1, 2 and 4–9 .

Adults. Wing ( Fig. 4 ) relatively short and broad, wing length (arculus to apex) about 1.2–1.3 mm, R5 joining costa posterior to wing apex and R5 thickened near junction with Rs. Antennae with 12 flagellomeres in both sexes; male flagellomeres binodose ( Figs. 5 ), each node with a single set of circumfilar loops and with loops subtended by sharply tapered setae angled out at about 45 degrees from the longitudinal antennal axis; female flagellomeres cylindrical with very short necks, first and second flagellomeres separated in some specimens but connate in others. Eyes large, holoptic ( Fig. 5 ), with eye-bridge 8–10 ommatidia long and with 7–10 fronto-clypeal setae; maxillary palps 3–4 segmented; labellae rounded, each with 8–10 lateral setae; abdominal tergites 1–6 narrowly rectangular, with continuous rows of up to 40 setae along posterior edges and a few additional lateral setae; tergite 7 more quadrate and with fewer setae arranged irregularly in 3–4 rows; female tergite 8 much shorter and smaller than tergite 7 and with only a few weak, scattered setae in posterior half; ovipositor retractable ( Fig. 6 ), about twice as long as tergite 7; cerci dorso-ventrally flattened, with two pairs of thickened sensory setae in distal quarter and some shorter, weaker setae ( Fig. 7 ); male genitalia ( Fig. 8 ) with cerci slightly separated medially; hypoproct dark and thick; gonocoxites cylindrical and gonostyles tapering gradually towards terminal claw-like combs; aedeagus short and parallel-sided, rounded distally (but collapsing in permanent slide mounts).

Larvae. No recently collected specimens were available but remains of three larvae extracted from galls collected in Walayar Forest by Odette Rohfritsch in 1971 have the sternal spatula blade reduced to a single small tooth ( Fig. 9 ).

Pupae. The only specimens available are the remains of four male pupae dissected in 2009 from galls collected by Odette Rohfritsch at Walayar Station in 1971. These do not have any armature on the cephalic sclerites and, so far as can be seen, conform with the pupal characters given for Contarinia carolinae Gagné in Gagné & Marohasy (1993).

Material examined. HOLOTYPE male no. 20500, INDIA, Sirukadambur, near Gingee, Tamil Nadu; reared from 'piston and rod' galls on Acacia ferruginea , by S. Amerjothy, vial 2, 06.iv.2007. Paratypes males nos. 20499, 20501, 20502, 20621; and females nos. 20497, 20498, 20503, 20622, 20623, with same data as holotype. Holotype and paratypes deposited in the Natural History Museum, London, UK.

The following additional specimens were studied: 5 larvae (on slides 20625 and 20626), and 3 pupae (on slide 20624), retrieved in October 2009 by the author from galls collected at Walayar Station by Odette Rohfritsch in 1971, and 2 larvae (on slide 20627), also retrieved from galls collected near Madras by Odette Rohfritsch in 1988.

Biology. Rohfritsch (1971) reported that C. manii (as Lobopteromyia sp.) was known only from one locality on the eastern side of the Western Ghats and that mature galls, which are 5–7 mm long, were present in February and July, indicating the occurrence of at least two adult generations per annum, at the end of the short rainy seasons in November and June. She also established that the host plant is Acacia ferruginea D.C.. Her anatomical studies are particularly detailed and show that gall development is initiated by the first instar larva and continues so long as live larvae are present. She also reported that a special nutritive tissue develops in these galls. This species has since been found at a number of locations near Madras.

Etymology. This species is named after the late Professor M.S. Mani in recognition of his studies of Indian plant galls and his major contributions to cecidological research over many years.

Comments. Contarinia , as currently defined, is a large, catch-all genus and C. manii does not fit well into even the broad generic definition used here. Final instar larvae do not have the terminal pair of recurved corniform papillae that are so characteristic of most known species and the sternal spatula blade is reduced to a single tooth, whereas sternal spatulae of most known species have a bilobed blade with a long shaft. In addition, the pupa of C. manii lacks cephalic setae and has very short thoracic spiracles; females have an unusually short ovipositor; males have a darkened and thickened hypoproct and the galls are much more complex than those induced by most known species of Contarinia . The same applies to C. carolinae and, so far as is known, to C. ramachandrani . These differences suggest that these species are part of a monophyletic group of species inducing complex galls on Acacia in East Africa and southern India and that group may also include C. bivalviae (Rao) , which induces bi-valved leaf galls on Acacia catechu in India. Further collections of adult, pupal and larval material are needed to provide the basis for more detailed study of the inducers of these remarkable galls and efforts should be made to record and conserve them.

Figures

FIGURES 1, 2. Contarinia manii sp. nov., 1, a single gall formed from two contiguous leaflets of Acacia ferruginea; 2, section through a single gall showing a third instar larva in the cavity formed between the upper and lower sections of the gall; gall length 4 – 5 mm. Photographs by Dr. Odette Rohfritsch.

FIGURES 4, 5. Contarinia manii sp. nov., 4, female wing. Wing length = 1.2 mm; 5, head, male, frontal view, scale bar = 0.1 mm.

FIGURES 6 – 9. Contarinia manii sp. nov., 6, female, lateral view showing retracted ovipositor. scale bar = 0.1 mm; 7, female, cerci at tip of ovipositor, dorsal view, scale bar = 0.01 mm; 8, male genitalia, dorsal view, scale bar = 0.05 mm; 9, sternal spatula of third instar larva, scale bar = 0.01 mm.