1908] 



Biologic gI Notes on Potato Beetle 



161 



THE LARVA. 



I. Length of Instars. Observations on this point were not 

 extended owing to the fact that it was impossible to make them 

 continuous in time. Larvae hatching from 49 eggs (deposited 

 at 2 p. M., May 31st, by pair No. 2 of the hibernated individuals) 

 at 6 A. M., June loth, molted for the first time at 9 p. m., June 15th;, 

 the time of other ecdyses not recorded. Forty-four larvae hatch- 

 ing at 5 A. M., June 25th, molted for the first time at 6 a. m., 

 June 28th, and for the second time at 7 a. m., July i, but the 

 time of the third ecdysis was not recorded. The following table 

 shows the only complete observation made on the duration of 

 the larval instars. 



table IIL Duration of Larval Instars for a Single Cycle. 1907. 



2 . Number of Ecdyses. The number of ecdyses recorded for 

 fifty larvae during the season of 1907 was three (3), excluding 

 pupation, and there were thus four distinct larval instars {Vide 

 Girault, 1907). 



3. Length of Stage. The duration of the larval stage was 

 correctly determined for a few lots only; the observations on 

 several others being interrupted at critical periods, thus des- 

 troying accurac}'. The accompanying table summarizes. 



table IV. Duration of the Larval Stage for Three Cycles, 1907. 



