38 THE EEPOET OF THE No. 36 



them on pieces of ripe apples and peaches, both of which they relished greatly. I 

 do not know the length of life of these autnmn adults, but five specimens caught 

 in September were still alive almost a month later when I removed them from 

 the cages. The last adults were seen in the open on October 11th. One found 

 then was ovipositing. 



Eggs. — Oviposition probably begins early in August, but with the very limited 

 time at my disposal the first adult I could find doing this was on September 29th. 

 After that date I saw several both in the cages and outside. It is very probable 

 the beetles found in May oviposit in spring, as in Europe, eggs are laid both 

 in autumn and in spring. The eggs are laid, as one would expect, at such 

 places on the tree as we find the injuries later. Sometimes this may be at the 

 base of a bud or small branch, but on the Balm of Gilead trees under observation 

 and also in the cages it was just as commonly on the internodes, sometimes where 

 there was a small rupture in the bark, sometimes where there was no rupture. 

 About one hundred egg punctures in all were observed and several ovipositions. 

 Before laying the Qgg the female eats a small hole, usually easily visible to the 

 eye, through the bark to the full depth of her proboscis; at the bottom of this she 

 makes one, two or three cavities. Where there are more than one they are a 

 little distance apart from each other. Then she turns around, inserts her pro- 

 truded ovipositor into the hole and lays an egg in each cavity. The making of 

 the hole and laying of the Qgg is a slow process. I observed one which had 

 already been at work some time when noticed and from the time she was first 

 seen until the eggs were laid was a little over thirty minutes. One female was 

 observed after laying the egg to turn around and insert her beak into the hole 

 many times as if putting in small particles of bark. The eggs are pale trans- 

 lucent whitish, oval, about 1.5 mm. long and a little more than half as wide as 

 long. Each female probably lays many eggs. One about to oviposit was dis-' 

 sected and only three mature eggs were found in the ovaries, all the others being 

 much smaller. 



It is hard to say how long it takes the eggs to hatch. As stated the first 

 oviposition was observed on September S9th, but an examination from time to 

 time of egg punctures at Guelph revealed no larva until October 7th. On October 

 25th, fourteen egg punctures on a Balm of Gilead were examined and in five 

 of these sound unhatched eggs were seen, in five others tiny living larvae, and 

 in the remaining four hatched eggs but no larvse. All previous examinations 

 showed more unhatched eggs than larvae on all trees. 



Larvce. — The freshly hatched larva is white, curved, and has a brown head. 

 Full-grown larvae are, as shown in the photograph, stout, about half an incli 

 long, white, curved and have a brown head and no legs. 



The young larvae found were in every case very near where the eggs had 

 been deposited, and had not eaten their way through the bark. They appeared 

 to be settled down comfortably for the winter. Only in one case was there any 

 evidence of a larva having reached the cambium, and that one was doubtful. 



The discovery of so large a percentage of healthy eggs along with these tiny 

 larvte would suggest that the winter is probably passed in the egg stage as well 

 as the larval. We saw above that it is apparently passed also either in the adult 

 or pupal stage or both, with a slight possibility of there being some full-grown 

 larvse too remaining over in the burrows. 



A study of the burrows shows that in spring the larva?' work obliouely 

 into the sapwood, throwing out many castings at first as they do so. When thev 

 have gone in some depth the entrance appears to become closed, at least in poplars, 



