BEETLES. 



349 



far the history of their life is sufficiently strange, but the next change of habitat is 

 still more curious. At the moment when the female bee deposits her egg upon the 

 surface of the honey in her cell, the active young triungulin passes from the bee to 

 the egg, upon which the larva rides, as upon a boat, thus avoiding drowning in the 

 honey about it. The bee's cell is sealed, and then the triungulin begins eating into 

 the egg of the bee ; the contents of this egg just suffices as food for the larva about 

 eight days, when it moults and appears as the second larva. This second larva, unlike 

 the triungulin, is not in danger of drowning in the honey about it, and feeds upon it. 

 In the latter part of summer the second larva attains full growth, and enters the 

 pseudo-pupal state. Most of these insects hibernate as pseudo-pupae, although a few 

 appear as images about the beginning of September. The pseudo-pupae which hiber- 

 nate go through the third larval and the pupal stages from June to August of the 

 next year, appearing as beetles about the middle of August. 



Hornia minutipennis, an American species allied to Sitaris, was found by Dr. C. 

 V. Kiley to be parasitic upon Anthophora sponsa, but its life history is still incom- 

 plete. The imago is about 0.5 of an inch long, with no wings, 

 and the elytra are so extremely rudimentary as to be scarcely 

 noticeable. 



Among other genera of Meloidae of which more or less is 

 known concerning their life history is Zonitis mutica, a French 

 species, whose hypermetamorphosis takes place in cells of Osmia 

 tridentata. 



Meloe includes wingless beetles, which have very short, im- 

 bricated elytra that do not nearly cover the abdomen. M. 

 angusticollis is a steel-blue species common in the eastern 

 United States. Its length is from 0.40 to 0.75 of an inch. 

 The females of Meloe are very prolific, and sometimes lay as many as from three to 

 four thousand eggs. The life history of Meloe has not been as well studied as has that 

 of Sitaris, but there is no doubt that its earlier stages are passed, in analogous mode 

 to those of Sitaris, in the nests of bees. 



The STYLOPID^E are insects of very abnormal structure and habits, and are regarded 

 by some naturalists to be a separate order, Strepsiptera, and by others are assigned to 

 this position next the Meloidae. The males have rather peculiar form, small, partially 

 rolled up elytra, and very large wings which fold like a fan. Their eyes are large, 



coarsely facetted, and, in Stylops and Xenos, are 

 mounted upon pedicels. In the adults of both sexes 

 the mouth-parts are rudimentary. Prothorax and 

 mesothorax are short; the metathorax is, on the 

 contrary, greatly developed. Sexual dimorphism is 

 carried to its extreme degree among the Stylopidae, 

 and although the males are capable of locomotion 

 and possess good eyes, the adult females are wing- 

 less, eyeless, and legless parasites, remaining buried 

 between the abdominal segments of wasps, bees, and 

 ants, there enclosed in their pupal-skin which they 

 never shed, and pushing out into open air only their anterior end between the seg- 

 ments of their host. Their eggs, which drop directly from the ovaries into the body- 

 cavity, develop in the latter place, possibly parthenogenetically at times, although 



FIG. 391. Meloe angusti- 

 collis. 



FIG. 392. Xenos pecki ; a, Elytra. 



