The Life-History and Habits of Diaxenes den- 
drobii, Gahan, with Notes on Prevention and 
Remedy. 
BY 
R, STEWART MACDOUGALL, M.A., D.Sc. 
With Plates I. and II. 
It is safe to say that scarcely a year passes in which our 
country does not receive from other countries accidental 
additions to its insect fauna, these additions being either indi- 
viduals of an already native species whose numbers are thus 
swelled, or perhaps quite new species. Such insects as aphides 
or scale-insects, which feed externally, may be introduced on 
nursery-stock or fruits, to which they are securely anchored by 
a proboscis. Apart from these, many insects pass a part or 
much of their life in the various stages of egg, larva, pupa, or 
adult, under the bark of trees, or in the wood itself, or sunk in 
the tissue of smaller plants; hence driftwood and imported 
timber and plants are fertile sources of the new insect additions 
above mentioned. 
In my notes of the last two years, I have mention, as taken 
from driftwood, of living adults of such destructive forms as 
FTylesinus piniperda, Prssodes notatus, and Bostrichus steno- 
graphus ; also of the living pupz (the beetle being afterwards 
bred out) of Lamza edzlis, the Timberman, a coleopterous insect 
not common in our country. Again, a few months ago, in a 
piece of timber imported from America, I found on examination 
a living specimen of Goes figrina, a North American longicorn 
beetle. 
Notes, R.B.G., Edin., No. 1, 1900.] 
