STREPS1PTERA 01' STYLOPIDJE. 



217 



ABNORMAL COLEOPTERA. 



STEEPS1PTEKA or STYLOPID^E. 



Minute species, parasitic in the interior of Hymenopterous or 

 Hemipterous insects ; prothorax reduced to a narrow hand ; elytra 

 aborted, reduced to small, more or less twisted, slips; metaihoraos 

 very large ; wings of male very large, longitudinally folded when at 

 rest; tarsi two- three- or four-jointed, without claivs ; male free, 

 metagnathous (i. e. with the mouth adapted for sucking in the imago 

 and for biting in the larva ) ; female blind, larviform, and never 

 quitting its host. 



Probably many more genera and species of these remarkable 

 insects exist than have been yet discovered. They have been 

 fouud in Europe, North America, Brazil, Africa and Mauritius, 

 and stylopized bees have been observed in Tasmania and other 

 countries ; most probably they are represented in the Indian 

 region. 



They are parasitic on various Hymenoptera and Hemiptera, and 

 their life-history, so far as at present known, is very strange. 

 The female is a wingless grub which never quits its host. 

 According to the generally received accounts given by authorities 

 who have studied the insects, the female possesses a dorsal canal 

 by which the male effects impregnation ; the larva?, which are 

 active and campodeiform triungulins (as in Melo'6), escape by this, 

 the ova being developed and hatched in the coelom or body-cavity. 

 The Strepsiptera or Stylopid.e are therefore remarkable as 

 being viviparous ; this character, however, is found in many other 

 insects, e. g. the Axthomyidjg, various Muscid-E and Pcpipara 

 among the Diptera, certain Tineid moths, the Aphidje, some 

 Blattid.e, and a few Staphylixid-E among the Coleoptera. 

 There appears, however, to be some doubt with regard to the 

 accuracy of the above observations, more especially as regards the 

 dorsal canal of the female, and they must not be accepted without 

 considerable reservation. 



Very little, if anything, is known about the way in which the 

 young triungulins reach the larvae of the insects on w 7 hich they are 

 parasitic ; but when this is accomplished they bore into their host 

 and are transformed into legless and sluggish vermiform larvae, 

 subsequently pupating in the same situation. The male, when it 

 emerges, is free and very active, but the female remains within 

 the host, only the head protruding. According to Meinert (Ent. 

 Meddel. v, 1896, p. 148, and Overs. Danske Selsk. 189b', p. 67, 

 quoted by Sharp, I. c. ii, p. 302) the so-called head or cephalo- 

 thorax of the adult is the anal extremity, and he contends that 

 fertilization and the escape of the young are effected by the 

 natural passages, the anterior parts of the body being affected by 

 a complete degeneration. Sharp is inolined to agree with Meinert 



