22 BULLETIN 891, U. S. DEPARTMENT OF AGRICULTURE. 



come full grown, prepare their pupal cells a few inches to 8 inches 

 below the surface, and pupate within these. Pupation takes place 

 the latter part of May or first of June. 10 



During cold spells in late fall and during winter, the larvae pene- 

 trate deeper into the soil. In tidewater Virginia certain crops are 

 grown during winter under frames, and in such cases, when weather 

 conditions are mild, the larvae may continue active during the entire 

 winter. In the field, the larva? are active during warm spells in 

 winter, otherwise they remain inactive in the ground at a depth of 

 from 7 to 10 inches. Early in spring activity is much increased, and 

 as the larvae are approaching full growth at this time they often 

 prove injurious to plants sown at this time, and to others that are 

 set out. The larvae continue active until the beginning of June, their 

 activity ceasing gradually as the time for transforming to pupae 

 approaches. By the middle of June the majority have transformed. 



The newly-hatched larvae can live several days without feeding, as 

 long as the soil is moist. 11 



Observations on the feeding habits of the larva of the green June 

 beetle in the field in tidewater Virginia were made frequently from 

 the time the larvae were first hatched until they were ready to pupate, 

 and these, together with the experience of experts and farmers who 

 have had practical experience with this white grub, will serve as a 

 criterion in judging the injurious status of the larva to crops. 



From the time the larvae hatch until some time after the first molt, 

 they invariably work in the vicinity of where the eggs were de- 

 posited. Later they come nearer the surface of the ground. In the 

 trapping experiments conducted for control, only larvae that had 

 molted at least once were captured, indicating that before that stage 

 is reached they do not usually come to the surface. After the first 

 molt, the larvae are about three-fourths of an inch in length when ex- 

 tended. They become exceedingly active and their abundant numbers 

 in the soil are plainly visible by the numerous perforations and ridges 

 produced around the plants. 



Probably the most important factor in judging the injuriousness 

 of the larvae is their extreme activity in the soil. This activity is in 

 large measure responsible for the damage they do to crops. "Where 

 larvae are abundant seedling plants are thrown up from the soil or 

 buried beneath. In several instances two to three replantings have 

 been found necessary before a fair stand of plants could be obtained 



10 The notes in some of the foregoing- paragraphs are also recorded by Davis and Login- 

 bill (45). 



11 In vials of moist sand containing no food whatever larvae were kept alive for three or 

 four days after hatching without any apparent effect on their health. The data in regard 

 to the molts of the larva were determined by confining larvae in vials and supplying them 

 with fresh food daily by changing the soil. The soil was prepared by mixing sand and 

 compost in equal proportions. Under these circumstances the larva was reared from the 

 time it was hatched until it changed to pupa. The number of molts was thus determined. 



