INSTITUTE, PUSA, FOR 1918-19 ST 



mented by other papers, read at the same Meeting, on pests 

 of cotton, fruit-trees, borers in sugarcane and cereals, etc. 

 To these papers the following observations may be regarded 

 as supplementary. 



Cotton. The question of determining the relative im- 

 munity of the varieties of cotton was continued throughout 

 the year, and it was found that certain varieties appear 

 to enjoy a partial though not a complete immunity from 

 bollworm attack. Work on these lines has been consider- 

 ably hampered by the infestation of the cotton plants with 

 Pseudococcus corymbatus and Phenacoccus hirsutus and 

 later with Eriophyes sp. (probably E. gossypii). The 

 unusual appearance of Ps. corymbatus was traced to a plot 

 of soy bean closely adjacent to the cotton plots. The life- 

 history of this Coccid has been worked out, together with 

 those of its parasites and predators. . 



Hibiscus abelmoschus has continued to be a good trap- 

 crop for bollworms, a larger number of parasitized boll- 

 worms being found in the shoots and pods of this plant 

 than in either cotton or H. esculentus. As in the previous 

 year the number of Pink Bollworms (Platyedra gossypiella) 

 was found to exceed that of the Bollworms (E arias sp.) 

 from October onwards. 



Observations were made on a Bethylid ( ? Parasierola 

 sp.) found in affected cotton-bolls containing larvae of 

 P. gossypiella. Another Bethylid has also been obtained 

 from infected material received from Cawnpore. 



In the search for alternative foodplants of P. gossypiella 

 a large number of pods of Thespesia populnea was exa- 

 mined without result, but these pods were found to contain 

 Phycitid larvae boring in them. 



A short note on cotton bollworms was read at the Third 

 Entomological Meeting. 



A Gracillariad (Acrocercops sp.) larva was observed 

 to mine under the bark of cotton at Pusa (Plate VII). 

 It is an extensive borer and causes a layer of bark to peel 

 off the entire stem and even from the leaf stalks. This 

 insect has not been noted on cotton previously. 



