466 



BULLETIN 388 



cases she does not dig out extra cavities, but uses the hole made for the 

 deposition of but a single egg. When the cavity appears satisfactory, the 

 beetle inserts her ovipositor and deposits from one to three or four eggs, 

 depending on the kind of cavity dug. Then, reversing her position, she 

 closely packs the eggs, both with beak and with antennae, and covers 

 them with fine pieces of the wood. 



Egg laying continues from early August until October, but the number 

 of eggs laid by a single female has not been ascertained. Whether or not, 

 under New York conditions, all the females deposit all their eggs during 

 this period, has not been finally determined. All American workers 

 report that egg laying is finished in the autumn, and that the beetles do 

 not hibernate but evidently die after the process is completed. In the 



writer's work no hibernating adults were 

 found in the spring in the nurseries, 

 though it should be understood that no 

 extended search was made for them. In 

 the writer's experimental plot, adults 

 which evidently had hibernated were 

 taken on April 21, May i, and June 6, 

 1916. One was fresh and clean, appar- 

 ently having but recently emerged from 

 its pupal chamber. Though these were 

 observed, they may be only rare occur- 

 rences rather than represent a normal 

 mode of hibernation. Furthermore, egg 

 laying was not observed in the spring, 

 and in the treated plots there was no 

 evidence that any eggs were laid after 

 application of the various treatments. 

 Had egg laying in the spring been normal, certainly the treated plots 

 would not have shown such a high percentage of control. 



The egg 



The egg when laid is pure white in color but it becomes pale cream 

 when a few days old. The shell is very thin and fragile, somewhat viscous, 

 and without any distinctive markings. The egg is oval in outline, meas- 

 uring i.i by 0.8 millimeters. The shape varies considerably, since owing 

 to the softness of the shell it is easily modified by the shape of the cavity 

 in which the egg is laid. 



The egg stage lasts from eighteen to about twenty-five days, depending 

 largely on weather conditions. The first observation of eggs hatching 

 out of doors was on October 2, 1916. Undoubtedly many had hatched 



FlG. 115. EGG IN SITU, WITH OUTER 

 PART OF LENTICEL CUT AWAY 



