Feb. 14,1916 
Colorado Potato Beetle 
9 2 3 
NUMBER OF MOLTS AND DURATION OF INSTARS 
Eggs of the Colorado potato beetle were segregated and watched 
carefully to determine the number of molt 9 of the larvae and the time 
spent in each instar. It was found that every larva has three molts, 
with an average of about three days for each instar. Tables X and XI 
show the dates and number of days required for the molts. 
Table X .—Number of molts and dates of molting of Colorado potato-beetle larvce in IQ14 
Experiment No. 
Egg 
hatched. 
First molt. 
Second 
molt. 
Third 
molt. 
I. 
July 26 
July 29 
Aug. 2 
Aug. 1 
. 4 
Aug. s 
Aug. 3 
Aug. 8 
Do. 
Aug. 6 
Aug. 8 
Aug. 19 
Do. 
2 . 
2. 
July 3° 
...do. 
Aug. 2 
...do. 
0 
A . 
c . ... . , 
...do. 
...do. 
...do. 
J 
6. . 
...do. 
...do. 
...do. 
Aug. 7 
...do. 
Aug. 9 
Aug. 10 
Aug. 15 
...do. 
8. 
Table XI .—Duration {in days) of instars of Colorado potato-beetle larvce 
Experiment No. 
First 
instar. 
Second 
instar. 
Third 
instar. 
I. 
3 
4 
3 
2 . 
3 
3 
2 
2 
2. 
2 
4 
d 
A ... 
0 
2 
2 
4 
ET . . ...... 
0 
2 
2 
2 
6. 
0 
3 
2 
4 
2 
6 
4 
8. . 
3 
5 
4 
Maximum duration. 
2 
Minimum duration. 
6 
FALL MATING FOR SPRING EGG LAYING 
The fact that the Colorado potato beetle may be observed mating in 
September in the latitude of the District of Columbia has probably given 
rise to the opinion that a third generation might be produced elsewhere— 
e. g., in Minnesota. This last generation, whether second or third, has been 
proved in one instance to be fertilized in the fall, the females on issuing 
being capable of depositing eggs in the spring without a second copulation. 
This was found to be the case with the generation which held over from 
1914 and was observed in the spring of 1915, for a female came to the 
surface on March 8 and, without mating, deposited eggs on March 11 
and 12, which hatched on March 20 and 21. These larvae fed until 
March 30 and 31, when they pupated, the adults emerging on April 19, 
