334 



found in the grass alongside infested fields ; it does not appear to 

 enter the canes, but may keep down the froghoppers in intermediate 

 areas and so limit their spread. The mongoose, which destroys birds 

 and hzards and so encourages insect pests, is common in Grenada. 



A quantity of artificially prepared spores of the green muscardine 

 fungus was distributed over the damaged fields in Grenada and a 

 number of dead infected hoppers were subsequently found. In 1917, 

 the froghoppers appeared again in both fields, but not to the same 

 extent as in 1916. A map is given, showing the locahties in which 

 infestations of T. sacckarina occurred. 



Mad AN Mohan Lal (L.). Preliminary Report on Cotton Boll Worm in 



the Punjab, [Dept. Agric. Punjab,'] Lahore, September 1913, 6 pp. 

 [Received 6th June 1918.] 



In the Punjab the cotton bollworm^ [Earias ins^dana] breeds 

 actively from May to October, during which time it damages cotton 

 buds, flowers and bolls. The life-cycle is completed within 30 days. 

 In normal years this pest is naturally held in check by parasites and 

 by the summer rains. 



Two parasites of it occur, though one, a small yellow Ichneumonid, 

 is not of great importance owing to its small numbers. The other, 

 a Braconid, Rhogas lefroyi, Ashm. , is abundant, and multiplies rapidly, 

 but is highly susceptible to cHmatic conditions, being destroyed by 

 the severe cold of winter. 



Attempts have been made to keep this parasite under control 

 throughout the year by the estabhshment of permanent breeding 

 plots. These consist of about 2 acres of cotton which are infested 

 with parasitised bollworm and allowed to stand from one season 

 to the next, hollyhocks being planted to afford food and shelter to 

 the bollworm during winter. To guard against any considerable 

 diminution in the quantity of the host by the rapid multiplication 

 of its parasites and the consequent destruction of both, the bollworm 

 supply is kept as high as possible by introducing the moths into the 

 plot. In this way host and parasite are kept in equilibrium till 

 about the end of November, both becoming dormant during December 

 and January. The emergence of bollworms bred upon hollyhocks 

 takes place from February to June. Another alternative host-plant, 

 bhindi, has been found to yield parasitised bollworms by the middle 

 of May. Cotton buds attacked by bollworms may be found from 

 April to June, but these *are unparasitised, although R. lefroyi is 

 present in bhindi pods at the time. By the end of June cotton bolls 

 appear, 4 per cent, containing parasitised bollworms. 



R. lefroyi when extensively established is found only in bolls, not 

 a single case of parasitisation being recorded from bollworms in buds 

 and flowers, and it cannot therefore be estabhshed by means of intro- 

 ducing boxes full of parasitised bolls when bolls are absent in the fields. 



For the distribution of the parasite special boxes are used, the 

 tops of which are covered with a wire mesh sufficiently small to prevent 

 the escape of the moths, while allowing the parasites to leave them. 

 After the parasites are estabhshed in the fields of a certain locahty, 

 the boxes should be filled with bolls in which the bollworms have 

 already been parasitised and should then be sent out to other locahties. 



