394 JVilUam Morton Wheeler 



incipient colonies of the wasps. The triunguhns are, in all 

 probability, carried to these colonies by healthy wasps from the 

 flowers onto which they crawl from their mothers after hibernat- 

 ing in their hosts. 



Since the foregoing paragraphs were WTitten Pierce's fine 

 monograph of the Strepsiptera has appeared ('09). This work 

 contains such a full summary of all that has been published on 

 this remarkable group of insects, together with so much new 

 matter, that I should have thought it unnecessary to publish the 

 preceding pages, but for the fact that they were written for the 

 purpose of elucidating a problem which Pierce treats only 

 incidentally. Of the many interestingfactscontainedinhis paper 

 I shall cite only a few which have an immediate bearing on the 

 matters considered above. 



The fullest statistics given by Pierce relate to two large colonies 

 of Polistes annularis infested with Xenos pallidus. These colonies, 

 which were collected at Rosser, Texas, September 23, together 

 contained 1553 wasps, 131 1 males and 242 females. Of these 266, 

 or 1 7. 1 per cent were stylopized, 259 being males and only 7 

 females. The highest number of Xenos observed in a single 

 wasp was 15, and this occurred in a male specimen! Pierce also 

 cites some statistics published by Austin (1882) on 50 Polistes 

 metricus collected at Readville, near Boston, Mass., August 20, 

 1879. Of these wasps, 14 of which were males and 36 females, 9 

 or 18 per cent were stylopized (2 males and 7 females). 



Pierce figures the abdomen of a male wasp (Leionotus (Odynerus) 

 annulatus Say) which has the sclerites much distorted as in the 

 P. metricus shown in Fig. 2. Concerning his specimen, which 

 contained a female Leionotoxenus hookeri Pierce, he says: "It 

 seems that in pushing itself out between the segments the parasite 

 completely spht the dorsal tergites of segments three, four and 

 five and split segment two halfway to the base. The parasite 

 was located behind segment three." He cites the observations of 

 Perez on the effects of stylopization in Andrena and adds the 

 following modifications observed by Crawford in specimens of 

 Andrena crawfordi infested with Stylops crawfordi : 



"i. Puncturation of abdomen less strong, punctures finer and 

 sparser; especially noted on second segment. 



