70 ENTOMOLOGICAL NEWS. [Feb., '04 



spending variation in the bulk of the abdomen. This, no 

 doubt, is caused by abundance or lack of food. Taking the 

 difference in size of the male and the female into consideration, 

 all the larvae found in vigorous and strong plants were of uni- 

 form size. In the district where I collected these larvae and 

 pupae is a miniature mountain of coal-slack on which stunted 

 and dwarfed bushes exist. Although the canes were scarcely 

 thick enough for the larvae to form their pupal cells, nearly 

 every bush harbored a larva. All these were smaller in size. 

 Right after the change to the pupal stage the pupae are cream- 

 colored, but change gradually to reddish brown in the course 

 of two days. The larvae and pupae were left in sections of 

 roots or in a part of the cane, and these were placed on damp 

 soil in the cage, but nearly one-half of the number collected 

 succumbed to the unnatural conditions. Some of the larvae 

 perhaps were not mature when carried in. From 240 in all, 

 129 examples emerged, as follows : 71 males and 39 females of 

 marginata and 9 males and 10 females of the var. albicoma. 

 There were 168 males attracted to females, of which number 

 29 were albicoma. The two forms readily interbreed. I have 

 mated female marginata and male albicoma and vice versa. 

 Larvae and pupae were collected from June 28th to July 25th. 

 The first pupae were found on July 2d. By July 20th the 

 majority were in the pupal stage. The first imago emerged 

 August 8th, with males strongly in the majority until August 

 25th ; after that females were more numerous. The last few 

 days of August are the height of their period of flight. P'e- 

 males exposed on August 29th to September 3d attracted only 

 eleven males. Stragglers appeared in the cage up to Septem- 

 ber 1 2th, mostly all females. The pupal stage la.sts from 

 twenty-five to thirty days. Males attracted by females could 

 be seen from some distance ; they have a slow and hesitating 

 flight and carry the antennae erect when on the wing. Males 

 of albicoma are readily distinguishable from marginata even 

 when flying. The rings on the abdomen in newly emerged 

 males of albicoma are nearly white, and contrast strongly from 

 the deep-black abdomen ; but, as in all Sesiids, the lustre of 



