44 INSECT ARTIZANS AND THEIR WORK 



provisioning its cell with a cicada, an insect twice 

 its own weight. In the vicinity of moisture the 

 cicada rapidly becomes mouldy, so the wasp has to 

 make her burrow in dry earth. Her method of 

 getting her prey from the place of its capture is 

 ingenious : she hauls it up a tree until she has 

 reached a height sufficient to allow of her flight 

 with it on a descending plane, flying up from the 

 ground with such a load being a very difficult 

 matter. The feeding period of the grub only 

 extends to about a week, then it forms a cocoon in 

 which much earth is held together by its silky 

 secretion. 



One of the commonest of the British burrowing 

 wasps is Mellinus arvensis, a pretty black-and- 

 yellow-banded creature only half an inch in the 

 length of its body. It provides for its offspring 

 by supplying its burrows with two-winged flies. 

 To catch these it resorts to strategy. Certain 

 species of flies abound upon cow-droppings, upon 

 which they feed, and the congregation of yellow- 

 brown flies offers a fine opportunity for those 

 insects that prey upon them. But the flies are 

 very alert, and fly off with rapidity. Mellinus, 

 instead of at once opening attack, joins the throng 

 as though actuated, by similar tastes, and appears 

 to have no other design than to share their repast. 

 No resentment of her intrusion is shown, for there 

 is enough for all. But no sooner does she get close 

 enough to a fly to make her purpose sure, than she 

 pounces upon it, and carries it off to her burrow. 



