300 



STREPSIPTERA 



CHAP. 



male emerging very soon after the host has become an active 

 winged Insect, while the female undergoes no further change of 

 position, but becomes a sac, in the interior of which young 

 develop in enormous numbers, finally emerging from the mother- 

 sac in the form of the little triungulins we have already 

 mentioned. This is all that can be given at present as a general 

 account ; many points of the natural history are still obscure, 

 others have been merely guessed ; while some appear to differ 



greatly in the different forms. A few brief 

 remarks as to these points must suffice. 



Bees carrying, or that have carried, Strep- 

 siptera, are said to be stylopised (it being a 

 species of the genus Stylops that chiefly infests 

 bees); the term is also used with a wider 

 application, all Insects that carry a Strepsip- 

 terous parasite being termed stylopised, though 

 it may be a Strepsipteron of a genus very 

 different from Stylops that attacks them. The 

 development of one or more Strepsiptera in 

 an Insect usually causes some deformity in 

 the abdomen of its host, and effects consider- 

 able changes in the condition of its internal 

 organs, and also in some of the external char- 

 acters. Great difference of opinion prevails 

 as to what these changes are ; it is clear, how- 

 FIG. 154. Young larva ever, that they vary much according to the 



of Stulops on a bee's- -, -, -i ,1 f 



hair. Greatly mao-ni- species, and also according to the extent of 



tied. (After Newport.) the stylopisatioii. Usually only one Stylops 



is developed in a bee ; but two, three, and 



even four have been observed: 1 and in the case of the wasp, 



Polistcs, Hubbard has observed that a single individual may 



hear eight or ten individuals of its Strepsipteron (Xenos, 



n. sp. ?). 



There is no exact information as to how the young triungulins 

 find their way to the bee -larvae they live in. Here again the 

 discrepancy of opinion that prevails is probably due to great 



1 Although not an invariable, it seems that it is a general rule that the Stijlni>s 

 produced from the body of one individual are all of one sex ; it has even been 

 stated that female bees produce more especially female Stylops, and male bees 

 male Stylops. If any correlation as to this latter point exist, it is far from general. 



