FOOD OF INSECTS. 43S 



chrysalis a few weeks; and then breaks forth a four- 

 winged insect resembling, as before observed, the dragon- 

 fly both in appearance and manners, and preying in 

 like manner on moths, butterflies, and other insects a . 



The larva of Mynneleon formicarius is not the only 

 insect which avails itself of a trap for obtaining its prey. 

 A plan in most respects similar is adopted by that of a 

 fly (Mhagia Vermilio, F.) in form somewhat resembling 

 the common flesh maggot. This also digs a funnel- 

 shaped cavity in loose earth or sand, but deeper in pro- 

 portion to its width than that of M. formicarius, and ex- 

 cavated not by regular circles, but by throwing out the 

 earth obliquely on all sides. When its trap is finished, 

 it stretches itself near the bottom, remaining stiff and 

 without motion like a piece of wood, and the last seg- 

 ment bent at an angle with the rest, so as to form a strong 

 point of support in the struggles which it often neces- 

 sarily has with vigorous prey. The moment an insect 

 falls into the pitfall, the larva writhes itself round it like 

 a serpent, transfixes it with its mandibles, and sucks its. 

 juices at its ease. If the insect escapes, the larva casts 

 above it jets of sand with surprising rapidity 5 . 



I am, &o> 



a Reaum. vi. 333-78. Bonnet, ii. 380. 



b Bonnet, ix. 414. De Greer, vi. 168. L 10. 



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