REPORT OF THE SOCIETY 



111 



The beetles appear in May and June and lay their eggs below the sur- 

 face of the ground, usually near the roots of grasses. The grubs live for 

 over two years in the soil. Grubs hatched in June, 1910, change to pupae 

 in July, 1912, and emerge as beetles in May and June, 1913. 



Biological facts of importance have been obtained in recent years (see 

 Bulletins 116, 186 and 187, Illinois Agricultural Experiment Station, and 



Lachnosterna arcuata — a, adult beetle; b, pupa; c, egg; d. newly hatched larva; e, mature larva; 

 /, last segment of larva. 



Farmers' Bulletin 543, U. S. Department of Agriculture) regarding the 

 habits of white grubs, which may be summarized as follows: — 



(a) Some species have a life-cycle of two years, but most have a cycle of 

 three or four years. 



(b) The life-cycle tends to lengthen northward. 



(c) The adult beetles feed on the leaves of oak, ash, elm, poplar, willow, 

 maple, hackberry, plum and apple, during the night and migrate to the 

 soil in early morning. Mating occurs at night. They have been ob- 

 served feeding on corn and grass. 



(d) The eggs are generally deposited in the high grounds covered by vegeta- 

 tion near wood lands. 



(e) Clover, alfalfa and buckwheat are not injured, and small grains are not 

 so much injured as are corn, timothy, strawberries and potatoes. 



(f) As the grubs change to pupae about the end of July, disking infested 

 land as soon after that date as practicable destroys large numbers of the 

 tender pupae and adults in the ground. 



(g) Where grubs are small (first year) or large (second year) plowing up to 

 1st October destroys large numbers. 



(h) White grubs are most abundant in the neighborhood of trees. 



