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BULLETIN 1357, U. S. DEPARTMENT OF AGRICULTURE 



inches long closed with a cork. A piece of cloth placed under the 

 cork before the latter was pushed down into the vial was found 

 advantageous in preventing the beetles from laying eggs in the crev- 

 ices of the cork and also in absorbing any moisture of condensation 

 which might otherwise drip down the sides of the vial. 



LONGEVITY 



It was not possible to reduce to an arithmetical basis the longevity 

 of the adults in the greenhouses, because the time from emergence to 

 date of collection could not be determined. Beetles under observa- 

 tion lived as long as 234 days after date of collection. 



It seems probable that under favorable greenhouse conditions the 

 adults which emerge during the spring and summer months may live 

 from 75 to 100 days, whereas those which emerge later in the season 

 and pass the winter in the semidormant condition may remain alive 

 for a longer period. Tablei 2 indicates an average longevity of 52 

 days for reared specimens in confinement, although one individual 

 lived 364 days. 



Table 2. — Longevity of 45 strawberry rootworm beetles reared fram pup(B in 



1921 and 1922 



observations at WASHINGTON, D. C. 





Date of— 



Length 

 of life 





Number of beetles 



Emer- 

 gence 



Death 



Remarks 



3- 



1921 

 June 27 

 27 

 27 

 27 

 27 

 27 

 27 

 27 

 27 



27 



1921 



June 29 



July 1 



2 



9 



21 



27 



Aug. 17 



Oct. 19 



Dec. 4 



1922 

 June 26 



Days 



2 



4 



5 



12 



24 



30 



51 



114 



' 160 



364 



No feeding. 



6- 



Do. 



2. . 



Do. 



3 





1 _ 





1. 





1. 





6. . 



4 eggs from 1 beetle. 



1 



58 eggs. 



1- 



51 eggs. 







OBSERVATIONS AT DOYLESTOWN, PA. 



1. 



1921 



June 1' 



1' 



4T 



July 2 



Aug. 3 



3 



4 



1922 



June 27 



27 



30 



July 7 



17 



27 



27 



29 



29 



Aug. 1 



7 



16 



1921 

 June 16 

 Sept. 6 

 July 7 

 Oct. 3 

 Sept. 22 

 Aug. 30 

 Oct. 17 



1922 

 June 28 

 July 25 

 Aug. 14 

 14 

 Nov. 1 

 Aug. 21 

 Sept. 21 

 Aug. 3 

 Oct. 26 

 Aug. 22 

 Nov. 1 

 Sept. 21 



15 

 97 

 33 

 93 

 50 

 27 

 74 



1 



28 

 45 

 38 

 107 

 25 

 56 



5 

 89 

 21 

 86 

 36 





1. 



40 eggs. 



1 



No data on egg deposition. 



I. 



Do. 



1 



Do. 



1 



Do. 



1. 



Do. 



1 





2. 





1. 





1. 





1. 





1 





1 





1. 





1. 





1. 





1. 





1 









Total, 45 



2,343 













Days 



Average length of life 52 



Maximum length of life 364 



Minimum length of life . ,--. 1 



