:9o8] 



Biological Notes on Potato Beetle 



177 



the remaining beetles entered, (between the two dates, their food 

 had of necessity been neglected and had wilted) ; on October 17th 

 the seven were exhumed alive and placed on the surface of the soil 

 into which they had disappeared within an hour. They were 

 exhumed alive and liberated with the others on November i st . The 

 adults of lot No. 2 of this generation entered the soil together on 

 September 12th, and were undisturbed until liberated on Novem- 

 ber ist, all in good health and hibernating. 



Even when entering the conditions of hibernation in the warm 

 summer months, it seems almost impossible to break into the 

 habit and induce the beetles to feed or mate. Their physiological 

 condition must be profoundly modified in this state, as has been 

 found to be the case by Towner (1906, p. 2 45ff.) 



General Field Conditions, Supplementing the 

 foregoing. 

 I was unable to watch the beetles in the field at all closely, 

 so that but a few fragmentary observations were made; these 

 will serve, however, to give some idea of the general conditions 

 prevailing with the species in the late summer of 1907. It should 

 first be stated that the season of 1907 was very abnormal, in that 

 the spring was at first far advanced in March, it then being very 

 warm, and later in April retarded by a cold wave which killed 

 young plants and newly set fruit or the far advanced fruit buds; 

 planting was therefore much delayed in many cases, but data 

 kindly gathered for me by the Reverend Mr. C. L. Chapman of 

 New Richmond, showed that the potato crop was at least an 

 exception. The following table compiled by Mr. Chapman shows 

 the relative times of planting and harvesting of the potato crop 

 in the vicinity of New Richmond, Ohio, for the three seasons 

 past. 



TABLE XL Relative Times of Planting and Harvesting Potato. 1905-1907. 



From the table, it appears that the crop remained in the field 

 somewhat later than usual in 1907, and this would apparently 

 have some bearing on the breeding of the beetles. 



