350 



FAMILY CERAMBYCIDAE 



and more especially so in its young state. The larval gallery is always tightly 



packed with the wood refuse and excreta ejected by the larva, and is 



about 5 in. to 8 in. in length, with an average breadth of j in. On 



becoming full - grown, the 



grub bores down into the 



sapwood at an angle for 



about half an inch to one 



inch, and then eats out a 



pupal chamber parallel to 



the long axis of the tree (fig. 



237 (3)). Both chamber and 



entrance-gallery in the wood 



are kept quite free of wood- 



dust and excreta. When 



mature, the beetle crawls up 



the entrance-tunnel in the 



wood, bores through the 



bark which overlies it, and 



leaves the tree. 



Larvae in various stages 

 up to nearly full-grown and 

 full-grown were taken from 

 trees in Naini Tal towards 

 the end of May. Several 

 of these grubs had already 

 bored down into sapwood 

 and constructed the pupal 

 chambers and commenced 



to pupate. 

 "' 



237. Section of stem (with bark removed) of 



. . 



"', ,1 QuercHs dilatata showing the galleries of the larvae of 



Xylotrechus Stebbingi, Gahan, in the bast and sap- 



the wing towards the end of wood (2) ; I, la, larvae; 3, pupal chamber in sapwood 

 July and in August, the (all reduced ^). 



pupal stage lasting from six weeks to two months. As the beetle issues 

 so late in the season, I think it is improbable that there is more than 

 one generation of the insect in the year. It is possible that the beetles 

 issue at intervals (as the larvae mature) through a part of July, August, and 

 into September. The larval stage is thus about nine months. 



I first obtained larvae of this insect from oak-trees near Kilba in the 

 Bashahr State in 1901. I had asked the Range Officer to watch some trees for 

 me, and he forwarded me some beetles from the trees the following August. 

 This little beetle does not commit the serious damage to the timber 

 occasioned by Lophosternus hiigelii, since the pupal 

 chamber is onl Y constructed in the inner layers of the 

 sapwood. When in numbers, however, it is capable 

 of entirely destroying the bast layer of young trees, and in this way, when 



