Some Hypermeiamorphic Beetles 13 



STYLOPIDAE 1 



This family of beetles has always presented difficulties to en- 

 tomologists and probably will for some time to come. On ac- 

 count of their peculiarities a large amount of literature has been 

 written about them. But from all this literature a very small 

 proportion of facts can be obtained, the remainder being expres- 

 sions of doubt, or surmises which prove incorrect. If a student 

 were to apply himself to the task and make careful collections 

 he ought to have no difficulty in procuring a large amount of 

 material. The editor of the Entomological News in a note, Oc- 

 tober, 1903, states that from two nests of Polistes texanus Cress, 

 from Pecos, Texas, one hundred and forty wasps emerged and 

 thirty-four were stylopized by Xeuos sp. "Most of the Xenos 

 appeared to be females, and only four males were secured. Many 

 of the wasps had a number of parasites on them." 



•Mr. Hubbard in the Can. Ent., 1892, pp. 257-61, states that he 

 found Polistes americanus Fabr. from Florida very commonly 

 stylopized by Xenos sp. Mr. Hubbard found that the males were 

 numerous, that they emerged early in the morning, lived but 

 fifteen or twenty minutes, and that the Polistes crushed them to 

 pulp as soon as they fell to the ground, dead. This accounts 

 for the scarcity of males in collections. Mr. Hubbard suggests 

 that if the cage were provided with a false floor of wire netting 

 through which the dead Xenos could fall, perhaps more speci- 

 mens could be procured. 



Since most of the literature on the subject is available, the 

 author will merely give the bibliography and confine his remarks 

 mainly to observations made upon the material at hand through 

 the aid of the works listed. 



THE GENERA OF STYLOPIDAE 



Antennae with third joint lobed or flabellate I 



1. Antennae with four joints, fourth simple; tarsi four- 

 jointed Xenos Rossi 



(Pseudoxenos Saund., Paraxcnos Saund., Hylechthnis 

 Saund.) ' 

 ^ee pi. I, figs. 1, 2, 4, 5, 6, 7, 13; pi. II, figs. 3, 4. 



165 



