404 RHYNCHOPHORA. [Scolytus. 
SCOLYTUS, Miiller (Zccoptogaster, Herbst.). 
This genus contains about thirty species, of which about half are 
found in Europe, and the remainder have been described from North, 
Central and South America, and from Java ; several of the Huropean 
species also occur in Northern and Central Asia; the characters given 
for the tribe will be sufficient to distinguish this the single genus 
belonging to it; the life history of the species is of great economical 
interest, as the ravages that the beetles commit upon forest and fruit 
trees are often most serious ; the commonest British species is S. des- 
tructor, which destroys vast numbers of elm trees throughout the country, 
whole avenues of fine trees being sometimes ruined by its devastations : 
the larva of this species is figured by Westwood (Classification I. p. 350, 
fig. 42, 4); it is a thick fleshy grub, of a whitish colour, broader in front 
than towards apex where it is somewhat narrowed ; the head is corneous 
and provided with powerful jaws; the back is much wrinkled, and 
there are no traces of legs; a very interesting paper on ‘‘ Observations 
of the economy of the British species of Scolytus,” was published in the 
Entomologist’s Monthly Magazine (vol. vi. 1869-70, p. 126), by Dr. 
Algernon Chapman ; this gentleman still continues his valuable observa- 
tions on the group, and two years ago (November, 1888) I received 
letters from him regarding certain species ; as the subject is one of such 
general interest, it may be of service to quote a portion of his remarks 
at length, more especially those referring to S. destructor, concerning 
which he says:—‘‘ This, the commonest of our species, may be found 
early in June making its galleries of oviposition in any elm trees felled 
during the previous winter, and usually in such numbers as to ensure 
the destruction of the bark; I do not remember to have seen it in 
timber smaller than 8 in. diameter. The female makes her way along 
the bottom of some crack in the bark, often by widening it for some 
distance, before commencing to burrow, so that the real opening of the 
gallery is some distance from where the little heap of outturned frass 
lies which marks its orifice. 
“The male is present for only a brief interval, viz. after the burrow is 
well commenced, but before any eggs are laid. The burrow is usually 
about three inches long (very rarely five inches), almost always close to 
the wood and slightly encroaching on it. Its construction occupies 
about three weeks. The eggs are laid along either side close to the bark, 
the cavities in which they lie being somewhat irregular, not nicely fitting 
the egg as with Hylesinus. The eggs in a burrow number about 100, 
but I have met with more than 160 in one. They are covered by a 
rather thick continuous layer of frass, which also lines the floor of the 
burrow, and extends partially into the roof. 
“The young larve, starting at right angles to the parent gallery, 
which is parallel with the axis of the tree, form a very regular ‘ typo- 
graph,’ at least in those somewhat rare instances in which contiguous 
