Part I.] Stebbing ; Insect Pests of the Himalayan Oaks. 
19 
Further, both as a means of discovering the number of insects in a 
forest and as a means of protecting that forest as well, ' trap trees ’ should 
be arranged for. Trees which are either sickly, already attacked, or are 
chosen for other reasons, should be selected and girdled or felled a week 
or so before the flight time of the beetles. The insects will resort to 
these to oviposit, and when egg laying has been completed and the trees 
are full of nearly full-grown larvse, the bark should be stripped off and 
burnt. 
Points in the Life History requiring further observations. 
1. Where and in what stages of its metamorphosis the insect hiber- 
nates through the winter. 
2. The times of appearance throughout the year of the insect as — 
(а) full-grown larvae. 
(б) mature beetles on wing. 
3. The number of generations passed through during the year. 
SPHAEROTRYPES QUERCl, Steb. 
Reference — Stebbing, On “Some undescribed Scolytidae of Economic Importance from (be 
Indian Region,” Indian Forest Memoirs, For. Zool. I, Ft. I, (p. 5). 
Nature of Attack. 
The female beetle eats out an egg gallery in the bast and sap wood of 
the tree, laying eggs in indentations on either side The larvse on 
hatching out mine out galleries in the bast in directions at right angles 
(about middle of egg gallery) or which trend upwards or downwards 
in the upper and lower parts of the egg gallery {cf. PI. VI, fig. 3). 
When numerous, the bast layer is entirely destroyed and the tree 
attacked dies. 
Previous Record of Insect. 
I have no previous record of this insect having been taken or 
described. I only took specimens of the beetle in two Moru oak trees in 
the grounds of Government House, Xaini Tal, and then only sparingly. 
Larvse were taken in one of the trees. 
The genus contains two species which commit serious damage to sal 
trees in the United Provinces and in Assam and a third, which may be 
identical with one or other of these in the Central Provinces sal forests. 
