﻿STEAWBERRY EOOTWOEM ON" GREENHOUSE ROSES 



17 



was thicker and contained small lumps, and which evidently served 

 as a means of keeping the two surfaces between which the eggs were 

 laid from pressing together and crushing them. 



The material forming this wall was translucent when secreted, 

 but turned dark and finally black about three hours later. While 

 the fluid was being spread the beetle rubbed its hind and middle 

 tarsi together, apparently for the purpose of removing the sticky 

 fluid which adhered to them. Although the legs were usually kept 

 well braced, the beetle occasionally supported the turgid ovipositor 

 with one of its hind legs. At times the ovipositor would be retracted, 

 only to be immediately extended again. The beetle turned slightly 

 several times to allow the ovipositor to reach a different spot, but 

 all reaching was done by the ovipositor alone and there was no 

 motion of the body which assisted in placing it between the leaf 

 surfaces. In another instance an adult was observed to begin ovi- 

 position at 7.15 p. m. and finish at 8.05 p. m., a period of 50 min- 

 utes, during which four eggs were deposited. 



A few records of duration of the preoviposition and postoviposi- 

 tion periods of strawberry rootworm beetles and of the number of 

 eggs deposited are contained in Table 7. 



Table 7. — Duration of preoviposition and postoviposition periods of the 

 strawberry rootworm beetle, 1921 



Date of- 



Emergence 



First egg 



June 1 





June 20-- 



97 





July 27.. 



27 





27. 



27 





Aug. 8.- 









Date of— 



Last egg 



Postovi- 

 i position- 



Death 5^"°*^ 



July 31-..- Sept. 6-. 37 



Aug. 12.. Dec.4... 114 



12 June26i| 318 



8 Oct. 19.. i 72 



11922. 



The maximum number of eggs laid was 216, and these eggs were 

 deposited by a beetle in 22 different egg masses in a period of three 

 months after it was collected in the greenhouse. Several instances 

 have been noted in which collected individuals have laid more than 

 100 eggs. Observations on caged beetles under greenhouse conditions 

 indicate an average of 135 eggs as the probable normal capacity of a 

 female. 



EGG STAGE 



Tlic e.2;g ffig. 7.) of the strawberry rootworm beetle is pale lemon yellow 

 when deposited and becomes slightly orange as it develops. It is elongate oval 

 and very slightly arched. The cephalic end is somewhat blunter than the 

 caudal end. The length is from 0.93 to 0.98 millimeters and the width from 

 0.25 to 0.27 millimeters. 



In grcenhoii.ses the eggs arc usually deposited on old dead leaves 



(fig. 4) more or less folded or curled. Although eggs have been 



found in such leaves on the soil, it is more than probable that they 



are laid before the leaf falls to the ground, since, where an infestation 



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