16 



January to April is considered the worst season for larval attack, 

 and cowpeas or kidney beans planted during these months have 

 but little chance of surviving. If planted during the rainy season, 

 they produce heavy vegetation, but bear few pods. The best time 

 for planting is therefore during October and November, when the 

 plants get sufficient moisture to grow rapidly at the start, and are 

 thus able to resist attack. 



The methods of study of the life-history of A. destructor are described 

 and tables are given recording the length of the various stages reared ; 

 nine generations were bred in the insectary from 23rd July 1917 

 to 22nd February 1918, Two Hymenopterous parasites that assist 

 in the control of A. destructor are the Chalcidids, Eurytoma jyoloni 

 and Paratrigonogastra stella, which are described. The percentage 

 of parasitism was observed to average 17, E. poloni being more 

 abundant than P. stella. 



Control of the earlier stages of the insect by spraying is impossible 

 owing to the manner of feeding. Oviposition can be checked by the 

 use of a repellent applied at the appearance of the first two leaves. 

 Tar-water has been used in this way in Australia against A. pliaseoli, 

 Coq, (French bean fly). Such a spray must remain on the leaf until 

 the danger period is passed and it must be applied uniformly to both 

 surfaces of the leaves. It is doubtful whether such a method would 

 prove economical. A poison-bait such as sweetened Paris green and 

 lead arsenate on the leaves of young plants would probably kill many 

 adult flies. The easiest and most economical remedial measm'e is 

 imdoubtedly by cultural methods. The immunity of certain 

 varieties and the best time for planting susceptible varieties should 

 be studied. If infestation by the larvae be so heavy that the young 

 plants have no chance to survive, it is best to sacrifice the whole field, 

 ploughing the plants under deeply before pupation has begim. Badly 

 infested plants should be pulled up, the soil about the bases which 

 contains the pupae being first loosened with a sharp pointed stick so 

 that it will come away with the plant. Badly infested petioles should 

 be pulled off and destroyed. Collection of the adults in nets helps 

 to check the numbers. Thorough and frequent cultivation and ample 

 moisture supply when the plants are young enables them to grow 

 rapidly and resist attack. As the flies breed freely in self-sown beans, 

 these should be destroyed. 



Del GuEiRCio (G.). A Tortricld Moth injurious to the Chestnut Tree 

 in Italy. — VAgricultura Coloniale, Florence, xii, no. 1, 1918, 

 pp. 21-30, 8 figs. (Abstract in Mthly- Bull. Agric. Intell. & PI. 

 Dis., Rome, ix, no. 9, September 1918, p. 1127.) 



The larval stages of Cydia {Carpocapsa) splendana are very injurious 

 to chestnuts in the Apeimines. The nuts fall prematurely and are 

 found to be punctured by a round hole, hidden by a mass of excreta, 

 which is the opening of the larval tunnel. From August to November 

 the infestation increases and when the drying of the chestnuts by fire 

 is begun in November many larvae leave the nuts after 24 to 36 hours 

 exposure to the heat. When the nuts have been dried and freed from 

 the pericarp, the worm-eaten ones should be separated from the sound 



