April, '151 



SHER^IAX: ARMY-WORM PARASITES 



301 



While admitting that the numbers involved are not large enough to 

 furnish an absolute criterion, yet the per cent of fly-eggs which pro- 

 duced flies give some interesting suggestions. The mortality among 

 the flies (from egg to adult) was less among those w^here there w^ere 2 

 eggs per worm, than among those which had one egg per worm, — and 

 the mortality was still less when there were 3 eggs per worm. This 

 suggests that where there are only one or two eggs per worm, the worm 

 may have sufficient vitality to prevent the development of the parasitic 

 larva inside the host. The highest percentage of flies was secured 

 where there were 3 eggs per worm, and from this we may argue that 

 when the worm bears 3 eggs there are enough parasitic larvae to more 

 certainly kill the host before the larvae perish inside and the parasitic 

 larvae can still find sufficient nourishment to mature. The per cent 

 of flies maturing declines consistently when we pass above 3 eggs per 

 worm until we reach 11 eggs per worm, but beyond this point the 

 numbers involved in the rearings are certainly too small to warrant 

 conclusions. Indeed, I feel that all above 8 eggs per worm are sup- 

 ported by too httle data to warrant any real dependence being placed 

 on them. 



We often reared 2 adult flies from one worm, in several cases, 3 flies 

 from one worm, and in one case we reared 4 adult flies {W. J/.-pustulata, 

 1 cf 3 9 ) from one worm which showed 4 eggs when caged. 



One worm showed 3 eggs July 29; on August 3d it was still active 

 though two parasitic larvae had certainly entered, yet the worm 

 partially pupated and then perished, neither moths nor flies developing. 

 In no case did we secure both a parasitic fly and an adult moth from the 

 same worm, nor did Professor Metcalf note any such occurrence in 1908, 



Rearings from Army-Worm Pup^ 



While looking into an army-worm outbreak in Haywood County 



in the mountains of western North Carolina, I secured a lot of pupae 



(not counted). From these we could not expect to rear W. 4-pustulata, 



or P. claripennis which leave the dead larval host. But we included 



a few separated fly-puparia which were found among the pupae in the 



field. All were put in one cage. Result: 



Army- worm Moths 23 



f Architas analis, Fabr 13 (6d^, 7 9 ) 



. n' 1 Goniomyia unifasciata, 'Desv. 10 (5cr, 5 9) 

 Tachma-flies < . , , , ' . . ^ 



Winthemia 4-pustulata, Fabr. Icf 



[ Phorocera claripennis, Macq. 1 9 



From the abundance of pupae in the field in Haywood County it was 

 evident that W. ^-pustulata and P. claripennis had not been so active 

 in subduing the worms as they had been at Neuse, where we found 



