36 



MISCELLANEOUS COTTON INSECTS. 



V)y Doctor Chittenden, would seem to indicate that tlie moth lii})ernates 

 over winter. Professor Gillette states that the eggs require four or 

 tiA^e days to hatch, and that the first eggs are laid al)out tivc and the 

 last about sixteen days after emergence. No record of the length of 

 the larval stage has been given. In Texas the eggs hatched in three 

 daj^s as against hve, and the pupal stage was six to eight days as 

 against ten to fourteen — approximately — in Colorado. The length of 

 the larval stage in Texas was twenty-three days. Thus the complete 

 life cAX'le from the time of oviposition until the moth lays most of her 

 eggs would recjuire in that section a))out fort}" days. 



Comparing the al)ove data with the life history of the garden web- 

 worm, as given on pages 12-13. many ])oints of resenil)lance will be seen. 

 From this analogy the hibernating moths of the beet army worm 



probably oviposit early in 

 April, the moths maturing 

 from them — those of the first 

 generation — being abundant 

 about the middle of Ma}-. 

 The second generation of 

 moths emerges during the 

 first or second week in July, 

 and the third a little over a 

 month later — earl}' in August. 

 A fourth generation of moths 

 midoulitedly matures by the 

 third w^eek of September, as 

 larva? ha\'e been taken in 

 southern California October 

 21 and November 5, in about 

 the san e latitude as southern 

 Texas. The hibernating moths would thus probably form the fifth 

 generation. Previous writers are doubtless correct in stating that in 

 Colorado there are but three generations. 



Owing to the destructive habits which this insect has shown in the 

 Colorado beet fields, its course in the cotton fields as it moves east- 

 ward will warrant attention. 



Parasites. — The July brood of larvtv which matured early in August 

 were badly parasitized by Pristoincrus texanus Ashm., Che/onus te,c- 

 anns Cress., and Apanfcli^s <(J(/onqu!niis Ashm. 



PLATYNOTA LABIOSANA Zell. 



Small green larvte of this species were found rolling up cotton 

 leaves at Terrell July 2, 1901:. They pupated July 11, and moths 

 emerged July 20. Mally has mentioned Pbitynota roxtmna Walk, as 

 sometimes working on cotton. '' 



Fig. 19. — Caradrina crir/iKi: a. moth; h. larva, lateral 

 view; c, larva, dorsal view; </, heart of larva; c, egg, 

 viewed from above; /, egg, from .side — all enlarged 

 (f,/, after Hofmann; a-<I, after Chittenden). 



« 1893: Bui. 29, o. s., Div. Ent., U. S. Dept. Agric, p. 30. 



