NOTES ON COLLECTING, ETC. 
91 
probably Sesia bembeciformis may sometimes remain two years in either 
the larval or pupal condition. — F. J. Buckell, Canonbury Square, N. 
March, 1891. 
Referring to Dr. Buckell’s statement as to the duration of the larval 
state of Cossus ligniperda, etc., I think there can be but little doubt 
that woodboring larvae live two, if nor three, years in that state. I 
believe there is little question that this is the case with C. ligniperda 
and Sesia sphegiformis and possibly also with Zeuzera cesculi, S. cynipi- 
formis, S. apiformis, etc., although I am rather inclined to the idea 
that the three last mentioned pass two years as larvae. I never heard 
of any one breeding any of these species from the egg, so one can 
only argue from finding larvae of two or three very distinct sizes in the 
burrows at the same time of year. — C. Fenn, Lee. April, 1891. 
Cossus LIGNIPERDA. — In August, 1890, I found, crawling on a road, 
a nearly full-fed larva of this moth, which I captured and fed on elm 
wood. On the loth of May last, I was pleased to see it had gone 
into pupa. It could only just have turned, as it was quite soft and of 
a light brown colour. It soon got harder and darker, and to-day, to 
my surprise, I found a lovely male specimen emerged. Is not this an 
exceptionally short time for it to remain in the pupa state ? I thought 
it always remained for a year or two. I might mention that I kept the 
larva in an ordinary wooden breeding cage, with glass front, and gauze 
at the top and sides, and it never attempted to gnaw its way out. 
Is not this also exceptional? — W. P. Blackburne-Maze, Boundes 
Park, near Tunbridge Wells. May 2^th, 1891. [When the larva of 
C. ligniperda is full-fed it makes an autumn cocoon to hybernate in. 
In the spring it generally leaves this cocoon, and without feeding, spins 
another in which it pupates, the moth emerging the following June 
or July. I have known a larva to pupate in the cocoon it hybernated 
in, but I do not think that it often does so. I have never before 
heard of the species not remaining in the pupal stage at least five or 
six weeks, nor have I heard of the pupal stage extending to more than 
eight or ten weeks, although the larva is two or three years coming 
to maturity. — Ed.] 
Times of Emergence. — I can only speak from memory on this 
point. I have found Nyssia zonaria drying their wings at 10 a.m. and 
at 4 p.m., and more than one at each time. They may possibly 
emerge at all times between, but I have not noticed. Zygcena 
filipendiilcE seems to emerge from 10.30 to 12 a.m. Sesia bembeci- 
formis emerges here from 7 to 8 a.m., Smerinthus populi, 6 p.m. I 
bred a lot of Vanessa cardui some years ago, in a room facing the 
west, and hot in the afternoon ; these emerged from 2 to 4 p.m. 
The effect of an east wind is very noticeable, even on pupae forcing 
on my kitchen chimney-piece. As soon as the wind changes to the 
east they stop, and wait till it goes round again. — Geo. A. Harker. 
April, 1891. 
On the broad lines I have stated (vol. ii., p. 70) insects emerge from 
the pupa with a certain regard to their times of flight, — a provision 
of nature, and one that will account for the fact that so very few 
captured females are infertile. By this explanation the emergence 
of butterflies, day-flying Sphmges like the Sesiidce, etc., would naturally 
take place in the morning ; and the rest some time either in the 
