ENEMIES AND THEIR INFLUENCE. 



397 



FIG. 333. FIG. 834. 



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

 loides sa'itidis. FIG. 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 cocoon, 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- 



vse. 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. O. Howard, 1 who thought them to be 



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



an entirely new genus.' 2 



This gentleman has lately published 3 a description 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. 



Salti- The eggg of ^jg S pi ( j er are a little more than a millimetre in 



Guests circumference, and each egg harbors but one parasite, which 

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

 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- 

 ard has named it Acoloides sa'itidis, 

 and a copy of the drawing of the 

 insect is given at Fig. 335. In the 

 same connection Mr. Howard de- 

 . scribes, under the name of Btuus 

 americanus, a new species, a mi- 



FlG. 335. FIG. 336. 



nute wingless Scelionime, 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." Dr. Marx, after examining the eggs, expressed 

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



1 Bureau of Entomology, Department of Agriculture, Washington, D. ('. 



2 Proceed. Acad. Nat. Sci., Philadelphia, 1884, page l'!4. 



3 " Insect Life," Vol. II., No. 9, 1890, page 269. 



hole. 



FIG. 336. Acoloides sa'itidis, a hymenopterous parasite 

 on the Saltigrade, Saitis pulex. FIG. 336. Bieus 

 americanus. (After Howard.) Natural sizes shown 

 in the circles. 



