126 
INoTeml 
OBSERVATIONS ON THE CEOONOMT OF THE BRITISH SPECIES 
OF SCOLYTUS. 
BY T. ALGEEFOlir CHAPMAN, M.D. 
1. ScoLTTTJs Eatzebtjegii, Janson. It is somewhat tmfortum 
that I should at the commencement of my observations be compel], 
(after the manner of a certain chapter «' On the Snakes of Iceland' 
to omit any remarks upon the very first species: Coleopterists, hoi 
ever, are well away that S. Satzeburpi has hitherto occurred with 
only at Eannoch, in birch trees; and further particulars of it will, 
course, be found in the "Entomologists' Annual" for 1856, p 86 ' 
which Mr. E. W. Janson introduced the species. All our remainii 
Scoli/h I have found in this district. 
2. ScoLTTus DESTEUCTOE, 01 This, the next largest in size 
S. Batzelurgii, and the commonest of our species, may be found ear 
m June making its galleries of oviposition in any elm trees fellf 
during the previous winter, and usually in such numbers as to ensii 
the destruction of the bark. I do not recollect to have seen it i 
timber smaller than 8-in. in diameter. The female makes her m 
along the bottom of some crack in the bark, often by widening it f( 
some distance, before commencing to burrow, so that the real openir 
of the gallery is some distance from where the little heap of out-turne 
frass lies which marks its orifice. 
The male is present for only a brief interval, viz., after the burra 
is well commenced, but before any eggs are laid, and I once found a pai 
tn cop. at this period. The burrow is usually about three inches Ion 
(very rarely five inches), almost always close to the wood and slightl 
encroaching on it. Its construction occupies about three weeks. *Th 
eggs are laid along either side close to the bark, the cavities in whic 
they lie being somewhat irregular, not nicely fitting the egg as wit 
Hylesinus. The eggs in a burrow number about 100, but I have me 
with more than 160 in one. They are covered by a rather thick col 
tinuous layer of frass, which also lines the floor of the burrow, an 
extends partially into the roof 
The young larvae, starting at right angles to the parent gallerj 
which is parallel with the axis of the tree, form a very regular " typo 
graph," at least in those somewhat rare instances, in which contiguoui 
broods do not interfere with each other. Most of the larv® are ful 
fed towards the latter part of July, and I daresay that, in favourabh 
seasons, there are sometimes two broods in a year. A certain proper- 
