288 Journal of Agricultural Research voi. 111.N0.4 



rushed from one crack to another until the proper place was found. 

 During the first week of July one female took 21 minutes from the time 

 she lighted on a tree to find a place to lay her eggs. Not a minute of 

 this time was wasted, and many cracks were rejected before the favorable 

 one was located. 



The cracks chosen for o\iposition were usually ones that were quite 

 deep. In one case a female used a crack which had evidently been made 

 by lightning, but in all other cases a crevice at the bottom of a deep crack 

 between ridges of the bark was chosen (PI. XXXVIII, fig. i). Since the 

 bark is usually rougher on the trunk and larger limbs, especially near 

 the ground, more favorable places to oviposit are found on these parts of 

 the tree. Observations were made 25 feet from the ground, but few 

 beetles were seen and none were looking for places to oviposit. In ex- 

 amining trees which had been killed, it was found in one case that an 

 egg had been laid in a crevice at the axis of a small branch 41 feet 6 inches 

 from the ground. On one tree which was very badly infested practically 

 every branch more than i]4 inches in diameter had burrows on it. 

 Many attempts were made to find whether the sunny side of trees was 

 preferred to the shady side, but, so far as could be determined, the beetles 

 showed no preference. From this evidence it seems that the eggs may 

 be laid on any part of the tree which afiFords suitable cracks and that 

 since such cracks are most numerous on the trunk, this is the usual place 

 for ovipositing. 



The females settled down when a favorable crack was found and were 

 apparently motionless during oviposition. The beetles stood in any con- 

 venient position during the process, and there was no relation between 

 the number of eggs laid and the length of time apparently spent in de- 

 positing them. Oviposition lasted from i to 5 minutes, and from i to 10 

 eggs were laid. It is probable that the number of eggs in a cluster de- 

 pends upon the favorableness of the crevices in which they are deposited, 

 because the females usually hasten to find another place as soon as one 

 cluster has been laid. Just how many eggs are laid in all by one indi- 

 vidual is not known. 



THE EGG 



Plate XXXVIII, figure 2, shows a very typical cluster of four eggs, the 

 average number, on a bit of bark taken from the bottom of a crack, just 

 as they appeared within an hour after they were deposited. One of the 

 eggs lies entirely exposed, showing the typical form of an undisturbed 

 egg, while the others illustrate how nicely they mass together and fit the 

 irregularities of the crevices. It will be noticed that the eggs are not 

 plump but have an unfilled, wrinkled appearance, which makes it possible 

 for them to fit into crevices of all shapes. A typical egg, such as the 

 exposed one in the illustration, is somewhat oval and measures about 

 940/t in length, ^iofi in width, and about 30o/( in thickness. The newly 

 laid eggs were covered with a glistening substance which stuck them 

 firmly in place when dry. 



