286 MAINE AGRICULTURAL EXPERIMENT STATION. I906. 



The White Grub. From the eggs develop the white grubs 

 which spent about 3 years feeding upon the roots of grass 

 and otlier plants before they attain their full size. When 

 grown they experience a period of rest in the pupal stage while 

 the transformation to the adult beetle takes place. 



Although grass roots are the native food of white grubs, a 

 great variety of plants of agricultural value are liable to attack 

 by them, — small grains, Indian corn, potatoes, and beets, to 

 mention a few. Strawberries are especially susceptible and 

 whole beds of these are sometimes destroyed if the plants are 

 set in newly broken or poorly cultivated soil. Young corn 

 meets the same fate if the grubs are thick in the soil. In 

 meadow lands the grubs are often numerous enough to kill 

 the grass over large spaces so that the loose sod can be rolled 

 back like a carpet. It is in places like this that skunks wax 

 fat and sleek, for they tear back the dead sod and eat great 

 numbers of grubs with evident delight. 



Natural Enemies. The white grubs are native insects and 

 are not without natural enemies. Besides skunks which have 

 just been mentioned, moles and ground squirrels eat them. 

 Toads and frogs are fond of the beetles and probably insec- 

 tivorous snakes deserve to be listed here. Great numbers of 

 birds feed upon either the grubs or the beetles, — among them 

 might be mentioned the robin, catbird, meadow lark, wood- 

 pecker, blackbird, crow, owds and hawks. 



Fungus parasitism is not uncommon with these beetles and 

 a few insect parasites, dipterous and hymenopterous, have been 

 bred from the white grubs. One of these, the curious Pelecinus 

 polyturator, recorded as parasitic upon the white grub by Dr. 

 S. A. Forbes, State Entomologist of Illinois, is given in the 

 accompanying illustration. This queer shaped parasite (Fig. 

 26) with slender crooked abdomen is common in Maine. 



Remedies. As these insects pass most of their lives under 

 ground, it is difficult to reach them with insecticides. Bisul- 

 phide of carbon, kerosene emulsion and poisoned baits have 

 sometimes been used successfully over small plots but both 

 the cost and the labor involved prohibit the use of the emulsion 

 and bisulphide of carbon over large areas. 



Fall plowing, thorough cultivation, and rotation of crops 

 are practical measures. In general any management which 



