1927] Notes on the Strepsiptera and their Hosts 191 
Finally, attention must be drawn to a matter of nomen- 
clature. It appears to have been overlooked that von Hey den 
(1868, p. 398) used the name Xenos smithii for two male para- 
sites of Sphex ichneumoneus L. from North America. Pierce 
(1909, p. 185) notes the specimens but apparently does not 
recognize the description. There can be no doubt of the validity 
of the name, however, for not only is the insect partly described, 
but also the name of the host, the essential part of many a more 
recent description of a strepsipterous parasite, is given. Homi- 
tops bishoppi Pierce (1909, p. 146), parasitic on Sphex ichneu- 
moneus L. at Waco, Texas, is known only in the female sex, while 
Xenos smithii was described by von Heyden from two males 
only. It is therefore possible to consider the former the female 
of the latter, especially as it is a common practice to couple male 
and female strepsiptera simply by their infestation of a single 
species of host. 
For loan of specimens I am very grateful to Mr. N. Banks of 
the Museum of Comparative Zoology, Mr. C. W. Johnson of the 
Boston Society of Natural History, Mr. Chas. Robertson of 
Carlinville, Illinois, Prof. W. M. Wheeler and Prof. C. T. Brues 
of the Bussey Institution, Harvard University, and Prof. Joseph 
Bequaert of the Harvard Medical School. My thanks are due 
to the various authorities to whom the host determinations are 
individually credited. To Dr. Joseph Bequaert I am especially 
grateful, not only for determination of the Vespidae.and for the 
gift of specimens, but also for generously allowing me to search 
for stylopized individuals in his large and valuable collection. 
References. 
Heyden, L. von 1868, Exotische Xenos-Arten. Berliner Entom. 
Zeitschr., 11, 398. 
Perkins, R. C.L. 1892, Stylopized bees. Ent. Mon. Mag., 28, 1-4. 
1918, Further notes on Stylops and stylopized 
bees. Ent. Mon. Mag., 54, 115-129. 
Pierce, W. D. 1909, Monographic revision of the twisted 
winged insects comprising the order 
Strepsiptera Kirby. Bull. U. S. Nat. 
Mus., 66, pp. xii and 232, 15 pis. 
