47(3 PKOCEEDIXGS OF THE THIRD ENTOMOLOGICAL MEETINfi 



usually immediately followed in summer by spimiing up and pupation, 

 but in the case of some larvae, especially those whose feeding period 

 closes in the late autumn or winter, it is followed by a resting j^eriod 

 which can last as long as two and a half years, perhaps longer. We 

 apply the terms " short cycle " larvae to those worms which pupate 

 immediately after feeding and "long cycle" or "resting" larvae to 

 such as intercalate a long period of rest between feeding and pupating. 

 Eesting larvae are usually found spun up inside hollow seeds, or " double" 

 seeds. A " double " seed is produced in the following manner : the 

 larva having hollowed out a seed, attaches another seed to the hollow 

 one, uniting the edges of the opening of the hollow seed to the new seed 

 by silk threads. The attachment of the two seeds to each other is 

 very firm and resists the action of the gins. The second seed is usually 

 eaten into. When no second seed is used, resting larvae spin up the 

 opening of the seed they inhabit ; double seeds often contain two worms. 

 It is not an infrequent occurrence for the larvae to use more than two 

 seeds for their resting shelter ; as many as six seeds have been found 

 utilized in this way. The seeds comjjosing " double " seeds usually 

 vary in their state of maturity. The original hollow one is usually 

 in the red umipe stage of development, the next seed or seeds being 

 black or ripe. 



The presence of Gelechia larvae in attacked green bolls cannot be 

 noticed without cutting open the boll, as the entrance hole made by 

 the larva is very minute and the larva does not keep it open nor enlarge 

 it in-order to void the frass as Earias larvae do. For this reason it is 

 not possible to control the Pink Bollworm b}' collecting attacked green 

 bolls. When full fed, short cycle larvae leave the bolls by a hole they 

 make. This hole might be mistaken for the work of an Earias larva, 

 but that the frass left by such larvae is wanting. 



The winter is passed in the larval stage, mostly by " resting " larvae. 

 However in the months January to March 1916 we were able to prove 

 the existence of a very slow-feeding brood, which was found in bolls 

 collected off the groimd in fields previously under cotton, but culti- 

 vated with bersim, beans, wheat or barley. (Bulletin No. 4, Technical 

 and Scientific Service.) 



The resting stage larvae are to be found in seeds of cotton, okroe and 

 H. cannabinus during the winter. First picking seed by March contains 

 only very few larvae as compared to the number of seeds attacked, 

 second picking seed contains a greater proportion of larvae. From 

 this it is concluded that the worms infesting the bolls at the time of the 

 first picking are mostly short-cycle larvae, and that the proportion of 

 long-cycle larvae increases considerably during the 4 to 6 weeks which 



