Part I.] Steering : Insect Pests of the Himalayan Oaks. 
15 
Olstrlbutloa. 
At present I have only records of this insect from the Naini Tal and 
Kumaun oak forests in the North-Western Himalaya. 
General Appearance. 
Larva or Grub . — A small white elongate worm with a 3'ellowish 
head. The grub instead of being curved as is usual with bark boring 
Scolytid grubs is more or less straight and tapers slightly posteriorly, 
riate V, fig. 1, shows the larva. 
Pupa . — Whitish yellow with ordinary beetle shape. 
Beetle . — A small oblong black insect with a reddish chestnut tinge. 
Head with front slightly convex, shining, punctate, very finely trans- 
versely striate at sides with long scattered hairs on front and a fringe of 
hairs on mouth. Prothorax slightly broader than long, base truncate, 
humeral angles rounded, sides and apex forming a blunt ellipse ; surface 
convex, raised into a point medlanly and depressed posteriorly ; granulose, 
the granulations coarse on anterior half especially on disk and much finer 
posteriorly. Scutellum rather large, shining, convex, rounded. El^'tra 
slightly broader aplcally than prothorax and a fourth as long again ; 
truncate at base, apex strongly rounded ; surface shining, flat medianly 
and strongly declivous apically, the declivity shining and edged with long 
spiny hairs ; rest of surface with rows of punctures which are fine basally 
and medianly and confluent and rugose medianly. Under surface lighter 
reddish brown medianly with longish hairs dense laterally. Length 2‘5 
— 3 millim. 
Plate V, figs. 2, 2a show the dorsal and side views of the female 
beetle ; 2^, 2c the same of the male beetle ; shows the antenme 
enlarged ; and 2c a leg. 
Life History. 
The following notes on the life history are compiled from observa- 
tions made in the field during the latter half of May and the first half 
of June. The life history of the insect for the remainder of the year is 
at present unknown. 
The male insect flies to and settles on the outer bark of the tree and 
then bores into the bark eating out a straight tunnel, of the same 
diameter as itself, down to the bast laj^er and sap wood of the tree. On 
reaching the latter it gnaws out a small chamber which grooves both the 
bast and sap wood and is squarish in appearance (Plate V, figs. 3/), 4jo). 
