PARASITES OF SPIDERS AND THEIR EGGS. 55 



I here refer to another figured body parasite, which was overlooked 

 when prfvj5aring the material on parasitic enemies for Vol. II. Mr. L. O. 



Howard, of the Entomological Department of the Bureau of Ag- 



The Die- j-iculture, Washington, has described and figured^ Polysphincta 



yna *''' ^li^jtyi^rg ,jjj^\ [^^ parasitic larva feeding upon Linyphia communis. 



(Figs. 44 and 45.) The fly was raised from a larva found on a 

 young Dictyna volupis Keyserling. When taken, May 15th (1887), the larva 

 was about half as long as the spider's abdomen and about one-fourth as 

 thick. It was attached by the mouth to the front of the abdomen. May 

 IStli the host was dead and the larva full grown, larger than the spider 

 had been, and had begun to spin a cocoon. May 25th it changed to a 

 pupa, and the fly came out Juno 1st following. The adult parasite is a 

 beautiful little male two and five-tenths millimetres long. The sketch, 

 as copied from " Insect 

 Life," shows the posi- \^ 



tion whicli the para- 

 sitic larva assumed oil 

 the spider. In the col- 

 lection in which the 

 above species was tak- 

 en Mr. Howard found 

 five other small spiders, 

 four of which support- fig. u. fio. 4s. 



ed parasitic larvie upon ^"^' *"*• Polysphincta cUctynae much enlarged. Fig. 45. -Larval parasite 



on young spider, Dictyna volupis. (After Howard.) 



the dorsum of the ab- 

 domen, and one delicate cocoon from which a parasitic larva had been 

 taken. 



In the same journal- INIr. Howard reported another species of Poly- 

 sphincta found by Dr. W. H. Fox, of Washington, D. C, upon a young 

 specimen of Steatoda borealis. The larva was slender, cylindrical, white, 

 one millimetre long, apparently less than half grown, and was attached to 

 its host substantially as above described. It was taken in February, which 

 would indicate a larval hibernation of the jiarasite. 



Mr. Howard has described still another species of Polysphincta, P. 

 strigis, whose habits were quite fully observed. Mr. Nathan Banks found 

 the larva of this species feeding externally upon Epeira strix, at 

 Parasite gg,^ d^ff^ j^^^^g Island, May 11th, 1891. At the time of capture 

 on Epeira ^j^^ parasitic larva was considerably larger than the spider; it 

 spun up May 14th. When brought to Mr. Howard (May 18th) 

 the cocoon was completed in the vial in which Mr. Banks had placed the 

 specimen ; it was spun of dense yellow brown silk, was six millimetres long, 

 cylindrical, two millimetres in diameter and rounded at both ends. It 



' 1 Insect Life, Vol. I., page 106. ^ Insect Life, Vol. I., page 42. 



