NOTES ON THE LIFE -HISTORY OF STYLOPID/E. 



295 



and so far as I am aware from all other Stylopid females. It has 

 also segmental spiracles which are absent in the other forms, and 

 the males have very peculiarly^modified tarsi. 



Following is the description of 

 the female of Xenos pallidits : 



XP:XOS PALLIDUS Brues ('03). 



Female. Length 8-12 mm. Distinctly 

 more slender than A". /Vr/v'/or A", nigres- 

 ccus. Head black, except on the ante= 

 rior third, the lines between the colors 

 straight, transverse. Head in outline 

 more elongate than in the other two spe= 

 cies and less bowed on the sides, widest 

 quite near the posterior angles (see figure 

 2). Thoracic integument very dark, wrin- 

 kled as usual, its posterior margin grad- 

 ually slanting backwards on each side to- 

 ward the median line. Dorsal stripe very 

 distinct, always extending over seven 

 segments as shown by its constrictions, 

 distinctly marked posteriorly and not fad- 

 ing out indefinitely. Openings to the 



oviducts distinct, four in number, one on each of the four anterior abdom- 

 inal segments near the posterior margin. Abdomen more or less distinctly 

 constricted just before its tip. 



Described from over 90 specimens found associated with the 

 males of the species in the bodies of Polities annularis. 



In conclusion, I wish to thank Mr. F. C. Bishopp who col- 

 lected a considerable portion of the stylopized Polistes considered 

 in the foregoing notes. 



Fir,. 2. Exposed portion of adult 

 female of Xenos pallidits Brues. 



BIBLIOGRAPHY. 



Packard, A. S. 



'98. A text book of Entomology, MacMillan Co., 1898. 

 Brues, C. T. 



'03. A contribution to our Knowledge of the Stylopidre, Zool. Jahrb. Abth. f. 



Anat., Bd. 18, Heft 2, June, 1903. 

 Pierce, W. D. 



'04. Some Hypermetamorphic Beetles and their Hymenopterous Hosts, Univ. 



Studies, Univ. of Nebraska, Vol. IV., No. 2, April, 1904. 

 Sharp, D. 



'or. The Cambridge Natural History, Insects, Vol. 2, Macmillan Company, 1901. 



