335 



The distribution of parasites early in the season checks bollworm 

 infestation from the very beginning in the bolls. 



The effect of rainfall in June and July tends to prevent bollworm 

 increase, since affected buds, flowers and early bolls being weak, are 

 easily washed ofE the plants and the bollworms inside them are drowned 

 on the ground, this process being helped by a breeze preceding or 

 following the rain. 'As R. lefroyi can exert no influence on the boll- 

 worm in cotton during June and July, rains are the only potent 

 factors in determining the prevalence of bollworm in cotton during 

 this period. 



During years of drought, and in districts where the rainfall is 

 extremely scanty the early broods in cotton must be destroyed by 

 mechanical means. This is best effected by passing a long rope to 

 and fro over the upper third part of the plants to jerk off the affected 

 parts, after which the fields should be thoroughly irrigated. 



R. lefroyi oviposits externally on the body of the host, selecting 

 freshly-bored bolls in which the bollworm hes close to the rind. On 

 an average 5 to 10 eggs are laid, after which the bollworm soon dies. 

 The eggs hatch during the first day and the whole life-cycle occupies 

 only 9 days, the larval period lasting for 3, and the pupal for 5 days, 

 and it is this fact that renders it such an efficient check, since it com- 

 pletes three generations in the time that the bollworm completes one. 



Madan Mohan Lal (L.). Some Important Insect Pests of Cotton in 

 the Punjab. — Dcpt. Agric. Punjab, Lahore, 1917, 4 pp., 3 plates. 

 [Received 6th June 1918.] 



Though attacked by a variety of insects, the cotton crop in the 

 Punjab is seriously damaged by only three, viz. : — Cotton bollworm 

 [Earias insulana], red cotton bug [Di/sdercus sp.], and dusky cotton 

 bug [Dysd-ercus sp.]. The life-history of the cotton bollworm and 

 methods of controlling it have already been dealt with [see above]. 



The red cotton bug, which feeds upon cotton, bhindi, hollyhock 

 and similar plants, may be found in all stages of growth upon green 

 and open cotton bolls. Infested bolls yield light, valueless seed 

 and poor quality lint stained by excreta. Control by mechanical 

 means may be effected by shaking the plants over a vessel containing 

 water and a thin layer of kerosene. The best time for this is May 

 and June when the insects are on bhindi, and in August and September 

 when they are on cotton bolls. Their destruction once a month is 

 sufficient to hold them in check and prevent loss. 



The dusk}' cotton bug lives on the same host-plants, does the same 

 damage to cotton when present in large numbers during September 

 and October, and may be destroyed in the same way. 



BoDKix (G. E.). The Destructive South American Locust in British 

 Guiana. An Account of the Recent Locust Infestation. — Jl. Bd. 



Agric. Brit. Guiana, Demerara, xi, no. 1, January 1918, pp. 3-10. 

 [Received 11th June 1918.] 



Late in June 1917 a vast swarm of locusts invaded British Guiana 

 from Venezuela via Yarakita, where many descended, in the North 

 West District. The passing of this swarm,, which originated on some 



