144 BLOOD-SUCKING INSECTS 



as long or longer than her own body with an 

 armature effective for the penetration of the skin of 

 the victim. 



Thus far, there is no mystery in the habits of these 

 remarkable flies, though much remains to be elucidated 

 concerning the action and habits of many of the 6000 

 known species. They are not blood-suckers: the 

 mystery consists in the behaviour of Ophion luteus in 

 my own house. Several members of my family having 

 complained of being either stung or bitten by these 

 unwelcome visitors, always at night, usually after they 

 had gone to bed, I consulted all available authorities 

 on the nature of Ophion. Little was to be found about 

 the species in such books as were at hand, so I sub- 

 mitted the problem to Dr. C. J. Gahan of the British 

 Museum, who replied as follows : 



' It is one of the few Ichneumonidce which are known to 

 sting. It is doubtful whether it possesses anything in the 

 nature of a poison gland. The sharp process at the end of 

 the body is part of the ovipositor, and the pain experienced 

 when this sharp instrument is driven into one's flesh may be 

 merely due to the mechanical irritation, or possibly there 

 may be some small amount of poison secreted. The pre- 

 sence of a small, narrow poison sac has been recorded in one 

 or two Ichneumonidce, but so far as I know, not in Ophion 

 luteus.' 



Now the sting is followed in every case by considerable 

 swelling, accompanied by pain, which would not be the 

 effect of the stab of a needle. It seems almost certain 

 that some irritant must be injected into the wound, 

 possibly for the purpose of paralysing Ophioris 

 legimate insect victim, as in the case of the hunting 



