522 



gas. The gas can be measured by placing the cyHnder on a weighing 

 machine. The lid of the tank can be left off, but should be lifted with 

 a rubber ring and replaced when sufficient gas has been admitted. 

 Any weevils present will die within seven days. Maize can be kept in 

 the fumes of this gas for over a year without being affected for seed 

 or food or becoming reinfested with weevils. The gas is harmless 

 and only costs 6d. per lb. 



Mackenzie (J. M. D.). Some Notes on Forest Insect Pests in Burma. 



— Ind. Forester, Allahabad, xlvii, no. 8, August 1921, pp. 309-317. 



For many successive years serious defoliation of teak plantations, 

 has occurred and is usually due to the moths, Hyhlaea puera and 

 Pyrausta machaeralis. The attack begins when the leaves appear,, 

 and by the end of June whole plantations are leafless ; at the end of 

 August a fresh crop of leaves appears. The growing season of teak is, 

 from June to January. Late attacks of longer duration cause more 

 damage than the earlier ones, as they kill the leading shoots. The 

 teak bee-hole borer [Diiomitiis ceramicus), which has ruined some 

 plantations, is a more widely known pest. 



Figures are given showing the annual financial loss caused by 

 defoliation ; a fair estimate for existing plantations is probably 

 £15,000 a year ; useful information is also given on the making of 

 plantations. The introduction of pure stands has favoured the 

 increase of insects, while the removal of hollow trees and of scrub 

 destroys the nesting sites of such natural enemies as bats, lizards and 

 birds. These should be encouraged, especially the last-named, which 

 are feeding their young when hatching and dispersion of the larvae 

 are taking place. 



DuTT (H. L.). Report on the Administration of the Entomological 

 Section for 1^1^-1^.— Re pt. A^ric. DcM., Bihar and Orissa, 

 1918-19, Patna, 1919, p. 14. [Received 3rd September 1921.] 



During the year under review, attempts were made to control Agrotis 

 ypsilon by means of a parasite {Microgaster sp.). It was hoped to 

 breed this Braconid under artificial conditions, and to infest the first 

 brood of the moth with it in September. The aestivating parasites, 

 are usually dormant through the summer, but under artificial conditions 

 of temperature and moisture they emerged as adults in May and died 

 without multiplying owing to excessive heat and drought and the 

 absence of broods of the host. 



The eradication of the weed, Cleome chelidonii, had no effect on the 

 incidence of attack by A. ypsilon. 



DuTT (H. L.). Report on the Administration of the Entomological 

 Section for 1%!^ 20.— Kept. Agric. Dcpt., Bihar and Orissa, 

 1919-20, Patna, 1920, p. 13. [Received 3rd September 1921.] 



The work on the parasite [Alicrogaster] of Agrotis ypsilon was con- 

 tinued during the year with a view to breeding it on its host during the 

 summer and rains and inducing dormancy in the pupating parasites by 

 modifying humidity, so that adults should emerge in the autumn on 

 exposure to humid and cool conditions. The limiting temperature for 

 effective rearing of both parasite and host is 83° F. Fresh parasite 

 cocoons have been stored under similar temperature conditions and 



