Dec, 1904] Powell: Wings of Certain Beetles. 239 



during the winter months development is much slower. There are 

 but two moults during larval life, T. plastographus being rather 

 unusual in this respect, though Needham (1900) states that the larva 

 of the flag- weevil, Mononyclius viilpeculus has but two moults. The 

 larva (Fig. 32) is a white footless grub. The eyes are lacking and 

 the antenn?e are reduced to a minute knob. The spiracles have no 

 chitinous surrounding ring and are very hard to discern. 



It may be well to mention here some observations I have made on 

 the habits of this beetle of which I have seen no record. The male is 

 apparently polygamous in its habits. As is usual in this family the 

 work of making the burrow is shared by both sexes. In opening the 

 galleries I found that there were generally three adults in each gallery, 

 one at the end of each long arm and one at the center. Dissection 

 proved that in each case two of these are females and one a male 

 (when it was possible to determine the sex, it being very hard to 

 separate the sexes after oviposition had taken place). I believe that 

 the long arms of the gallery are made by the females, while the male 

 makes the short arm and keeps a position near the entrance to the 

 gallery, but I was not able to get positive proof of this. In some 

 galleries however, there were but two beetles, a male and a female ; 

 occasionally there were four adults to a gallery. 



The number of eggs laid in each pocket is variable ; in the ma- 

 jority of galleries but one egg is laid in each pocket, but in a number 

 of galleries examined several eggs had been deposited in each pocket, 

 the number varying from two to seven — in no case was a pocket 

 found with only one egg in it, while in those galleries with one egg to 

 a pocket, in no case was more than one found in each pocket. The 

 number of beetles in the gallery had no connection with the number 

 of eggs in the pockets. 



There is considerable variation in the size and number of the pro- 

 jections on the tip of the elytra, but this does not seem to be a sexual 

 variation. 



DendroctoJius valens forms a large irregular gallery under the bark 

 and the eggs are laid loosely among small chips or shavings along one 

 side of the burrow. This species works only at the base of the trees 

 whereas T. plastog-taphns works throughout the length of the tree. 



After hatching, the larvae feed on the sides of the gallery, en- 

 larging it in all directions. The larva moults, I think, three times, 

 but I am not absolutely sure of this point and it is possible there are 



