196 Maine Agricultural Experiment Station. 1918. 



Biological History. 

 summary of rearings. 



Length of the egg stage. The eggs are deposited in the 

 summer, but do not hatch until the following spring. 



Length of the first larval instar. A record which was kept 

 of 9 larvae which hatched between June i and June 4 inclusive, 

 may be tabulated as follows : 



6 ^molted to the second instar in 4 days after hatching from the egg, 



2 in 5 days, and 1 in 6 days ; average 4.5 days. 



Length of the second larval instar. A record which was 

 kept of 31 larvae which molted to the second instar between 

 June 1 and June 5 inclusive, may be tabulated as follows : 



1 molted to the third instar in 2 days after the first molt, 15 in 



3 days, 14 in 4 days, and 1 in 5 days ; average 4 days. 



Length of the third larval instar. A record which was kept 

 of 36 larvae which molted to the third instar between June 4 

 and June 1 1 inclusive, may be tabulated as follows : 



13 entered soil in 3 days after the second molt, 5 in 4 days, 9 in 



5 days, 8 in 7 days, and 1 in 8 days ; average 5 days. 



Length of the prepupal period. A record which was kept 

 of 79 prepupae which entered the soil between June 9 and June 

 28 inclusive, may be tabulated as follows : 



10 transformed to pupae in 5 days after entering soil, 8 in 6 days, 

 35 in 7 days, 10 in 8 days, 15 in 9 days and 1 in 12 days ; average 7 days 

 Length of the pupal period. A record which was kept of 

 61 pupae which transformed between June 15 and July 2 in 

 elusive, may be tabulated as follows : 



30 emerged as adults in 10 days after the pupal molt, 20 in 11 days, 



6 in 12 days, 3 in 13 days, 1 in 14 days and 1 in 16 days; average 11 

 days. 



Typical life history. The following is cited as a typical life his 

 tory: 4 eggs deposited in July (1916) hatched June 1 (1917) ; 1 molted 

 to the se:ond instar on June 5, 2 on June 6, and 1 on June 7; 1 molted 

 to the third instar on June 8, 1 on June 9 and 2 on June 10; 1 died 

 during third instar, 1 entered the soil as a prepupa on June 12, and 

 2 on June 15; 1 transformed to a pupa on June 18, emerging as an 

 adult on June 29; 1 transformed on June 21, emerging on July 2, and 

 1 transformed on June 21, emerging on July 3. 



Seasonal History in Maine. 



Unlike the other flea-beetles of our fauna, which hibernate 

 as adults, the blueberry flea-beetle passes the winter in the egg 



