COTTON 423 



named Rhogas Kitchcneri, Dudgeon and Cough, in the 

 province of Beni Souef, in Upper Egypt. This little 

 parasite has been found commonly in the first locality and 

 shows signs of spreading. The experiment, which was 

 conducted in India by Professor Maxwell Lefroy, in pro- 

 pagating the Rhogas parasite and introducing it into the 

 fields infected with boll worm showed that the diminution 

 in the percentage of attacked bolls was very large, but 

 the difficulties of propagation on a large scale in the 

 laboratory were so great that this scheme as a remedial 

 measure seemed well-nigh impracticable. The transfer- 

 ence of infected larvae or the parasite pupae to new 

 localities to enable colonies of the parasite to establish 

 themselves naturally promises to be of greater efficacy in 

 Egypt. Operations in this direction are being under- 

 taken by the Entomological Section of the Ministry of 

 Agriculture. 



The Rhogas or other Braconid parasites which may 

 attack the Earias boll worm can only do so when the 

 larva is feeding in the flowers, or when it has freshly 

 commenced to perforate a boll, or when it is leaving one 

 boll to reach another, or to pupate. During these short 

 periods of exposure if the parasitic Braconid does not 

 discover the larva the latter is apparently secure from 

 its attack, as after having entered the bud or boll the 

 entrance is quickly stopped by the excrement voided by 

 the feeding larva. In India, where Earias insulana and 

 E. fabia are both found attacking cotton, other Braconids 

 occur infesting their larvae, but it appears that none are 

 furnished with sufficiently long ovipositors to penetrate 

 deeply into the bore-hole made by the Earias nor have 

 any means of reaching the larva in the boll. In conse- 

 quence their attacks must be made in a similar manner 

 to those of the Rhogas here referred to. 



Having taken into consideration the fact that the 

 Earias boll worm feeds upon a very limited number of 

 plants, all belonging to the natural order Malvaceae, of 

 which cotton, bamiah and tehl are almost the only 

 widespread and plentiful examples in the country, Mr. 

 Willcocks recommended in i()o6 8 that certain preventive 



8 Year-book of the Khediv. Agri. Soc. for 1005, p. 87. 



