159 



emulsion, was the most effective substance. Successful formulae con- 

 sisted of about 4 lb. resin, 2 lb. soda and 4 lb. solignum, with or without 

 the addition of 1 lb. crude oil, in 25 gals, of water. An average of 

 10 gals per tree was required. Only one spraying could be given 

 for the test, the water supply was difficult, the trees were tall, and 

 the apparatus insufficient to reach them properly. Even under these 

 conditions, from 56 to 92 per cent, of the hoppers were killed. It is 

 thought that two sprayings should be given in order to exterminate 

 the pest, the first early in December and the second in mid-January. 

 A third might be given in the second week of February, if necessary. 



Ballard (E.) & Ramachandra Rao (Y.). Notes on Natada nararia, 

 Moore. — Rept. Proc. 4th Ent. Meeting, Pusa, February 1921, 

 Calcutta, 1921, pp. 153-156, 1 plate. 



The information given in this paper has already been noticed 

 [R.A.E., A, ix, 580]. 



DuTT (H. L.). Note on a Braconid Parasite o£ Agrotis ypsilon. — 

 Kept. Proc. 4th Ent. Meeting, Pusa, February 1921, Calcutta, 

 1921, pp. 157-163, 2 plates. 



Further work is recorded on the Braconid parasite of Agrotis ypsilon 

 on the hues previously suggested [R. A.E., A, ix, 76]. This parasite 

 oviposits exclusively on A. ypsilon, the eggs being laid on any part 

 of the host caterpillar, but generally on the dorsal side of the first 

 abdominal segments, while the larva is young Under artificial con- 

 ditions, as many as 400-500 eggs have been laid on one host, though 

 in nature the average number of parasitic larvae found in one cater- 

 pillar varies from 20 to 60. One female undoubtedly oviposits on 

 more than one caterpillar. The egg and larval stages of the parasite 

 vary from 28 to 34 days in January to about 25 in February, and 

 the period is reduced in warmer weather to about 17 in March and 

 about 12 in April. The pupal stage varies from 9 to 12 days in 

 November to about 17 in December, 11 in January and February, 

 and 8 in March. As the temperature rises towards April, the larvae 

 aestivate within the body of the host, emerging as adults in the 

 autumn. In the hills, this emergence begins with the break of the 

 south-west monsoon in June. The adults die after three or four 

 days, whether oviposition has occurred or not. 



Adults first appear in the field with the first generation of A . ypsilon, 

 in September or October, when the flood water is about to drain away, 

 but the percentage of parasitism by this generation is very low ; in 

 November and December the number of parasites increases enormously, 

 and 50 to 70 per cent, of the later generation of the moth are parasitised ; 

 this, however, is too late to save the crop. The activity of the parasites 

 is at its maximum in February and March. Many of the aestivating 

 pupae in the cocoons die during the extremely hot, dry winds in April 

 and May, or during the subsequent submergence under flood water 

 for about two months in the rains, only a few surviving in such 

 sheltered positions as deep cracks in the soil. The temperature and 

 moisture conditions in such situations are discussed. 



With a view to utilising this parasite as a control for A. ypsilon, 

 a study has been made of the factors that influence aestivation and 

 emergence, with the object of having at hand a sufficient number of 

 adult parasites, in September or October, for liberation when the 



