14 



The Bulletin. 



"We have indicated that there are several different species of the White 

 Grubs. As with the wire-worms and cut-worms, many of the species 

 seem to do but little injury, while the greater part of Grub injury is 

 probably due to only six to a dozen species. Of the groups of beetles to 

 which they belong, however, we have evidence of not less than thirty-five 

 to forty kinds in the State, with no doubt many more awaiting discov- 

 ery. 



Fig. 2. — White Grubs. Showing adult beetles at 3 

 and i. Larva eating roots of plants at 2, and 

 pupa at 1. 



(After Riley, Div. Ent, U. S. Dept. Agr.) 



Life-history and Habits. — The most comprehensive work in this coun- 

 try on the life-histories and habits of "White Grubs and their adult beetles 

 has been done at the Illinois Experiment Station under Dr. S. A. 

 Forbes.* But in the space of this Bulletin we can only give a general 

 condensed account of the life-history. 



The adult beetles appear in spring and early summer; they are the 

 common brown "May-beetles" which often enter our houses at night, or 

 the green "June-bugs," so familiar to children. The beetles mate and 

 the females deposit their eggs preferably in grassy or weedy fields. The 

 eggs hatch into the "White Grubs," small at first, but growing with age 

 to from 1 to IV2 inches in length, feeding upon roots of many plants. 

 The exact length of time required for the Grub to attain full growth is 

 uncertain, but seems to be from two to three years. It then changes to 

 a pupa, in a cell in the soil, and the pupa changes to a mature beetle, 

 which, however, may not emerge to live an active beetle life until the 

 following spring. In the writer's personal experience it is a common 

 thing to unearth the adult beetles in gardens in fall, winter, or spring. 



*Among the several publications on this subiect by Dr. Foi-bes I have been especially 

 interested in Bui. 116, 111. Exp. Station. "Life-history, Habits, etc., of White Grubs." 



