3o6 FAMILY CERAMBYCIDAE 



Beetle. This beetle greatly resembles holosericea, described above, in size, form, and 

 coloration. It can be easily distinguished from the latter by the fact that the furrow crossing 



the under-side of the head between the cheeks is very clearly and 



Description. strongly marked, and strongly arched backwards in the middle ; 



whereas in holosericea the furrow is either straight, slightly arched 



forwards, or feebly bisinuate and not quite so deep and well denned (Gahan). Length, 

 23 mm. to 28 mm. ; breadth, 6| mm. to 1 1 \ mm. 



The observations on the life history of this insect were made by 

 Mr. H. P. C. Armitage, Assistant Conservator of Forests, and recorded 

 in the Indian Forester in 1901. I give them here in cxtenso as they appeared : 



"Flight. At end of February and March. The eggs are laid in the 

 bark of newly felled or injured trees; so far as is yet 



Life History. known they do not attack healthy trees. A large 

 number of eggs must be laid in each tree, as I have 



found as many as thirty larvae in one small sapling, and never less than a 

 dozen or so in one tree. The young larvae when hatched commence 

 boring a tunnel in between the bark and the sapwood. The tunnels are 

 exceedingly tortuous, and completely ring the tree. The sapwood of the 

 tree has precisely similar markings on it. The larva, when full-grown, bores 

 a hole into the sapwood, but sometimes penetrates as far as the heart-wood 

 (my specimens went in about September, but I have known cases of their 

 going into the wood earlier). Here he pupates, shutting off his house from 

 the outside world by a neat door made of some calcareous substance. 

 I annex a sketch* showing the chamber made, which is always of much the 

 same shape and size. Here he remains until the end of the following 

 February or March, when he undergoes his last change and emerges as a 

 beetle. I am so far of opinion that there is only one brood a year, but this 

 requires further investigation. Imago emerges March ; larvae from April- 

 May to October; pupal chamber excavated, September to November. 



' Any one walking through our low-country forests in Ceylon, through- 

 out which satin-wood is to be found, cannot help 

 noti cing scattered through the forest either dead 

 branches of living trees or young dead trees of satin- 

 wood, completely barked and studded with fairly large holes. This is the 

 work of the sEolesthes. The effect of these tunnels is to cause the bark to 

 drop off in large pieces. 



" Natives frequently wound the bark of the satin to obtain the gum, 

 which flows fairly freely, and here the beetle generally finds an opening to 

 attack. 



' Viscum orientale, a mistletoe, also grows on satin branches, frequently 

 strangling and killing off the branch it is on ; this is another chance for the 

 borer, while trees growing on ridges are particularly liable to attack, as 

 they so often have branches broken off by the wind. So far as I know, 

 satin-wood (Swietenia chloroxylon) is the only tree attacked by this beetle. 



c 1 have not been able to reproduce the sketch. PI. iv and hg. 210 show the method of 

 pupation of this grub. 



