^ Indian Forest Records. [Yol. VI 
Mr. Stebbing in bis recent book on Indian Forest Coleoptera (Steb- 
bing, 1914, pp. 630—633, figs. 398, 399), refers to the insect under 
both specific names, and gives a short account of the method of ovi- 
position. The correct synonymy of the species is given below, on 
page 5 of this Record. Further rejports of damage assigned to this 
species were received from the Divisional Forest Officer, Jalpaiguri, 
Bengal, in August 1913 and from the Divisional Forest Officer, Buxa 
Bengal, in October 1913. 
Investigations in Bengal in 1913. 
At the request of the Conservator of Forests, Bengal, the writer 
visited Buxa and Jalpaiguri Divisions in November-December 1913, 
and commenced investigations into the life-history of the borer and 
its connection with the dying-off of Sal in the Duars Sal forests. The 
chief result of the enquiry showed that the borer, while apparently 
causing the death of Sal trees of 3 feet girth and upwards in a very 
striking manner, was nevertheless not the true cause of death, but a 
secondary factor only. It was determined that the beetle is unable 
to establish itself in perfectly healthy trees, but requires trees weak¬ 
ened by disease and practically on the point of death to complete an 
attack successfully. If an attack is made on a healthy Sal, the tree 
at once reacts by a flow of resin and drowns the beetle before it reaches 
the sap-wood. Even in trees considerably reduced in vigour by defolia¬ 
tion, creeper-stifling, etc., the beetle fails to establish itself. More¬ 
over, certain aspects of its breeding habits, the development of the 
ambrosia fungus on which it feeds, the absence of attack in the lower 
part of the bole in the early stages, etc., indicate that a definite state 
of unhealthiness is required. 
A note on the enquiry was submitted to the Conservator of Forests 
Bengal, (Forest Zoologist’s No. 263-51 of the 9th April 1914) but it was 
considered that the case for the non-culpability of Diapus furtivus 
was not established with sufficient certainty for general acceptance, 
and the Local Government of Bengal desired that the enquiry should 
be carried further. 
Investigations in Bengal in 1914-15. 
The writer accordingly visited the Sal areas of Jalpaiguri and Buxa 
Divisions again in December 1914 and January 1915. The enquiry 
was carried out on somewhat different lines, with the intention of deter¬ 
mining in what proportion the various species of Sal insects occurred 
[ 2 ] ' 
