206 



GENUINE SNOUT-BEETLES. 



The larvae of the "lace-wing flies" are also fond of such fat 

 morsels as the larvae of the plum curculios, and are not slow to 

 utilize such food whenever they can obtain it. 



Ants of many kinds destroy the helpless larvae as these leave 

 the fruit to enter the ground, and if the latter is kept free of 

 weeds and dusty, many perish before they succeed in entering - it. 

 This again shows that clean culture is of benefit in many ways ! 



It is stated that large numbers of eggs of the curculio are 

 eaten by a minute yellow Thrips, scarcely one-twentieth of an 

 inch long. 



Fig. 219. — Sigalphus curculionis, Fitch; a, larva; b, cocoon; 

 Division of Entomology, U. S. Department of Agriculture. 



c, pupa. After 



Besides such cannibal insects we possess other friends, 

 which are true parasites. At least two species are described, 

 both illustrated in Figs. 218, 219, and 220. In some years such 

 parasites are fairly common, and do good work, but as a general 

 rule they do not appear in sufficient numbers to act as an effi- 

 cient check, and there is but little doubt that if we wish to eat 

 fine plums we will have to work for them, otherwise the curculio 

 will certainly take more than the lion's share. 



Fig. 220.— Porizon conotracheli, Riley; a, female; b. male. After Division of 

 Bntomology, U. S. Department of Agriculture. 



