465 



SOME NATURAL ENEMIES OF MANGO LEAF-HOPPERS 

 [IDIOCERUS SPP.) IN INDIA. 



By T. V. SUBRAMxWIAM, 



Assistant Entomologist, Mysore Department of Agriculture. 

 (Plates XV & XVI.) 



To entomologists in India the three species of mango Jassids — Idiocerns niveo- 

 sparsus, I. atkinsoni and /. clypealis — are fairly well known, both on account of their 

 wide distribution and also on account of the serious damage the}' do to the mango 

 crop. In the course of our studies on these important orchard pests we have within 

 the past three years come across three natural enemies of the adult hopper and 

 one of the nymph. These are (1) a Pipunculid fly ; (2) a Stylo pid — both internal 

 parasites ; (3) an Epipyropid moth — an external parasite of the adults ; and 

 (4) a Dryinid wasp — an external parasite of the nymphs. 



The following are some observations so far made regarding the above-mentioned 

 parasites. 



1. The Pipunculid Fly {Pipunculus annulifemnr, Brun., sp. n.).* 



This is a small dark-coloured fly with a large head and large globular compound 

 eyes of a dark reddish colour (PI. xv, fig. 6). The female fly is provided with a very 

 sharp, fairly long, honey-coloured ovipositor, which is held pressed against the ventral 

 side of the abdomen. .\11 the three species of hoppers are parasitised by this insect, 

 but /. atkinsoni is the least attacked. 



Egg-laying by the flies has not been observed as yet. Full-grown and \'oung 

 maggots have been observed on the hoppers during November and December. 

 The young maggots are of a rich orange colour and have the peculiar habit of hopping, 

 like fruit-fly maggots, when placed on a smooth surface. 



The parasitised hoppers are very sluggish, the abdomen being much bloated 

 and tense. They seek dark and shady places underneath the leaves of mango or other 

 trees growing near by, fix their rostrum to the leaf tissue, and remain in that condition. 

 The full-grown maggot now makes a way out through the dorsal surface of the 

 abdomen, between two segments. The maggots drop to the ground and pupate under 

 the soil. The full-grown maggot (PL xvi, fig. 2) is pale-coloured and oval in shape, 

 with the anterior extremity narrowed and blunt. It is 5 mm. long and 3 mm. 

 across. The spiracle shows as a small funnel-shaped black depression, a little away 

 from the extreme posterior end, on the dorsal surface. The pupal period lasts for 

 14 to 19 days in captivity. 



The characteristic appearance of a number of hoppers adhering to the lower surface 

 of the leaves of mango trees in shady places, with the abdomen partly split asunder, 

 is a sure indication of the work of this parasite (PL xvi, fig. 1). 



2. The Stylopid Parasite {Pyrilloxenos compact us, Pierce). 



Dissection of a number of mango leaf-hoppers to find out the percentage of 

 parasitisation by the Pipuncuhd fly led me to the discovery of this parasite. The 

 female parasites (PL xv, figs. 2, 3) are very small, dark brown, elongate ovate creatures, 



* For the description of this species, see p. 469. 



