420 



RAVAGES OF INSECTS. 



and being blind, gropes about on every side, as the Cyclops 

 did for Ulysses and his companions, till he touches one, 

 which he immediately transfixes with his trident, elevates 

 into the air, that he may not be disturbed with its struggles, 

 and soon devours. The havoc which these grubs make 

 amongst the aphides is astonishing. It was but last week 

 that I observed the top of every 3'oung shoot of the currant 

 trees in my garden curled up by myriads of these insects. 



a, Laco-wir.L-ed fiy; h, the grub of tlie same, magiiitied; c, syrphus; d, larva of the 

 same devouring the aphides uf the elder ; t, the head magnified, to show the mouth. 



On examining them this day, not an individual remained ; 

 but beneath each leaf are three or four full-fed larvae of 

 aphidivorous flies surrounded with heaps of the skins of 

 the slain, the trophies of their successful warfare."* 



The larvae of the lace-winged flies {HemeroUdce, Leach) 

 are even more destructive to the aphides than either of the 

 preceding ; insomuch that Keaumur was induced to call 

 them the lions of the aphides. The mandibles ot the larva 

 of Hemerobius are somewhat crescent-shaped, and, like 

 those of the ant-lion, are hollow, by means of which they 

 suck the juices of their victims. These are rarely so 

 numerous as the two preceding families, but ihey make up 

 for their fewness in the voracity with which they devour 

 the little destroyers of our vegetables. 



* Intr. vol. i p. 264. 



