ENEMIES AND THEIR INFI.UENCE. 



397 



Fig. 333. Fig. 334. 



Fig. 333. Magnified cell of parasitic hymenopter, probably Aco- 

 loides sa'itidis. Fio. 334. Saltigrade cocoon, with parasitic 

 cells enclosed, somewhat magnified. The fly on the edge is 

 about natural size. 



October, 1884, Mr. F. M. Webster sent me from Oxford, Indiana, a 

 parasitized cecoon, evidently of some Saltigrade species, which appeared to 

 be that of Phidippus morsitans. The cocoon contained within the outer 

 flossy case about eighty cells or pupa cases and a num- 

 ber of mature black hymenopterous insects about one- 

 eighth inch long. (Fig. 334.) The cells were ovoid, 

 gray, blackish at the closed 

 end, probably from excre- 

 tions from the enclosed lar- 

 vae. One end was cut open, 

 showing where the insects 

 had escaped. (Fig. 333.) 

 With the exception of a few 

 hard, dry, yellowish brown 

 examples, all the eggs of 

 the spiders had disappeared. 

 The specimens were sent to Mr. L. 0. Howard, ^ who thought them to be 

 Proctotrupids, belonging to the subfamily Scelionina^, and seeming to form 

 an entirely new genus. ^ 



This gentleman has lately published » a descrii)tion of a hymenopterous 

 parasite on spiders sent to him by Mr. L. Bruner, of Lincoln, Nebraska, 

 which was collected from the eggs of a Saltigrade, Saitis pulex. 

 The eggs of this spider are a little more than a millimetre in 

 circumference, and each egg harbors but one parasite, which 

 issues by splitting the egg case open, rather than by gnawing a 

 hole. This insect belongs to the same family and subfamily and is prob- 

 ably the same species as that col- 

 lected by Mr. Webster. Mr. How- 

 ^~~--^^N;s^BSffl|^^,^<^ \ it^,J8^ ^''d has named it Acoloides saitidis, 

 V ^^'^^wSf^^-^ ^ f^%\^^^ and a copy of the drawing of the 



insect is given at Fig. 335. In the 

 same connection Mr. Howai'd de- 

 scribes, under the name of Bseus 

 americanus, a new species, a mi- 

 nute wingless Scelioninse, from spec- 

 imens sent him ten years ago by 

 Dr. Marx, who appears to have re- 

 ceived them from Col. Nicholas 

 Pike, of Brooklyn, New York. They are labeled : " Parasites in spider's 

 eggs in an orange cocoon." Di'. Marx, after examining the oggs, expressed 

 the opinion that the host from which these little parasites were established 



Salti- 

 grade 

 Guests 



Fig. 336. 



Fig. 336. Acoloides saVtidis, a hymenopterous parasite 

 on the Saltigrade, Saitis pulex. Fia. 336. Bteus 

 americanus. (After Howard.) Natural sizes shown 

 in the circles. 



' Bureau of Entomology, Department of Agriculture, Washington, D. C. 

 2 Proceed. Acad. Nat. Sci., Philadelphia, 1884, page 294. 

 » "Insect Life," Vol. 11., No. 9, 1890, page 269. 



