86 
Indian Forest Records. 
[VoL. IX 
piirposes of feeding and pupation. In the majority of cases the depth 
to which the hun’ows are carried- does not exceed inch and in the 
rest the inside limit is usually the heartwood, e.g. : — 
Anogeissus laiifolia hy Olenecamptus curvipes {Lamiidae) ; Greivia 
tiliaefolia hy Ceresium leucosticum (Cerambycidae). 
The damage caused by this group is confined to the outer layers 
of sapwood, although the appearance of a log seen before cutting up, 
covered with wood-dust and its surface riddled -with holes, may be 
deceptive. The powder-post beetles (Bostrychidae) in particular 
reduce the sapwood to dust, but whatever its breadth their tunnels 
do not extend into the heartwood, e.g. : — 
Dalbergia Sissoo by Sinoxylon crassuni. 
In those trees without differentiated heai-twood the depth to which 
the galleries of sapwood borers may penetrate rarely exceeds 
inches, but occasionally the whole log is affected. Thus in Butea 
frondosa or Schrebera swietenioides the tunnels of Xylotrechus smei 
run deep into the core, whereas in other timbers the same borer is 
confined to the surface layers. 
7. Dey wood Borers (Bostrychidae, Ceramhycidae). 
The borers of seasoned or utilized timber are restricted to a few 
small groups of insects, but the species comprising them are 
omnivorus. Soft-woods and sapwood are more liable to damage than 
the lieartwood of hard woods. The tunnels are of two principal 
types: — 
(1) Running irregularly through the wood, closely packed with 
wood-dust, eventually reducing all but a thin outer shell 
to dust, e.g. : — 
Stromatium barbatuvi (Cerambycidae) and Heterobostrychus 
■aequalis (Bostrychidae). 
(2) Confined to a nan-ow (-| to 1 inch) zone on the surface of the 
timber, which is reduced to powder before the inner layers 
are attacked (Lyctidae and Anobiidae). 
The dry -wood borers are more properly speaking borers of utilized 
wood-products than of wood in process of seasoning. The majority 
of timbers is unlikely to be attacked after seasoning and methods of 
prevention need scarcely be considered. Remedial measures include 
simple treatment with linseed oil, kerosene and creosote, napthalene 
in petrol, etc., and antiseptics generally. 
Finally under special circumstances old or decayed timber may be 
used by carpenter bees (Xylocopa spp.) as nests. 
Damage by white ants is a subject to be considered entirely apart 
from boring insects. 
[ 232 ,] 
