PROCTOTRYPIDAE 



535 



the position in which they have fed up, enclosed each one in a 



more or less dis- 



tinct cocoon. In 



Fig. 352 we re- 



present a very 



remarkable case 



of Proctotrypid 



FlG ' 



' pu P ation of Proctolrypes sp. in body of a beetle 

 larva. 



DUDation' a 



larva of some 



beetle has nourished many specimens of a species of the genus 



Proctotrypes, and the pupae thereof project from the body of the 



host, a pair of the parasites issuing from each segmental division 



in a remarkably symmetrical manner. 



Comparatively little is known as to the habits of the members 

 of this family, but such information as has been obtained leads 

 to the conclusion that great variety will be found to exist in 

 this respect. We have already mentioned that numerous species 

 have been ascertained to feed inside the eggs of Insects or of 

 Spiders ; others have been reared from larvae or from galls of 

 the minute Dipterous midges of the family Cecidomyiidae ; 

 others have been obtained from Cynipid galls, a few from ants' 

 nests and from green-fly ; some species are known to attack 

 Coleoptera. The distinguished Irish entomologist, Haliday, has 

 written an account of the proceedings of a species of Betliylus} 

 from which it has been supposed that this Insect carries off living 

 caterpillars, and stores them in a suitable receptacle as food for 

 its progeny, thus anticipating, as it were, the habits of the 

 fossorial division of the Aculeata, in which group this instinct 

 has, as we shall subsequently relate, attained an astonishing 

 degree of perfection. Haliday's observation was unfortunately 

 incomplete and has not been subsequently confirmed. The 

 Bethylides are remarkable for their great approach in structure 

 to the Aculeates, so much so that entomologists are not agreed 

 as to whether certain Insects are Proctotrypids or Aculeates. 

 Pristocera, with a very wide distribution, may be mentioned as 

 illustrative of these doubtful forms ; but other genera of the 

 Bethylides are in many respects very similar to the Aculeates, 

 and it is not matter for surprise that Haliday should have con- 

 sidered the Bethylides to be a tribe of the stinging Hymenoptera. 



1 Entom. Mag. ii. 1835, p. 219. 



