iio First Report on Economic Zoology. 
Various methods have been unsuccessfully tried, particularly the 
following : — 
Fumigation, either with tobacco or a compound known as “X.L. All” 
(this is supposed to contain nicotine, camphor, methylated spirits, etc.), 
but neither has any material effect. Quassia affects them only for a short 
time, as they leave the pots and return in a few days. The pots have been 
placed under water for hours, but upon being taken out the flies are equally 
as lively as before. Fly-paper and strings similarly covered are of no avail. 
(N.B. — The houses are regularly fumigated for pests, in general about 
every ten days.) 
I should be very glad to know if there is any method of ridding 
ourselves of the pest by destruction or of making it harmless to the 
germinating seed and bulblet by driving it from the pot or otherwise. 
Any information as to its known habits might help us to work out its 
destruction if no remedy is known. It is of course important that any 
remedy shall be harmless to the orchid seedlings themselves. They are 
extremely delicate and porous and have to be kept in a constant state of 
moisture. 
I must apologise for having troubled you with so long a letter, but the 
ravages of this insect are most annoying and often rob us of results which 
have promised to be of great interest in the horticultural world, and I 
should feel much indebted if you could let me know of a remedy or of any 
one who would be likely to advise me should you personally be not 
acquainted with one. 
I beg to remain, etc., 
(Signed) Jeremiah Colman. 
Report on Insects in Orchid Houses. 
The insects sent by Mr. Colman, of Gatton Park, Surrey, causing 
harm to orchids, are in too broken a condition to identify accurately. The 
small flies are Sciarince and belong to the genus Zygonema , of which only 
one species occurs in Britain — Z. sciarina (Meigen), found in summer and 
autumn in underwoods and moss — but without seeing fresh and perfect 
specimens it is not possible to be certain of the species. The life-history 
is not known, but probably they breed in the damp moss. The larvae do 
not seem to have been observed ; they would possibly be in the form of 
small white footless grubs. 
The flies can do no harm — it would be the larvae — but there is no 
doubt that the damage is done to the orchids by the wingless creatures 
sent at the same time. There is no connection between the wingless 
insects and the Sciarinae. The wingless forms are Cotlembola , or Spring- 
tails. Some of these are certainly very injurious, but little is known of 
them, however. The young of these Spring-tails resemble very closely the 
adult, and live and grow in similar situations and under similar conditions 
and are injurious during the whole of their existence. Preparations have 
been made of this Collembola, and attempts will be made at its 
identification. 
The majority of species live under damp moss and stones and are no 
doubt encouraged by the methods necessary in orchid cultivation. All 
that can be suggested is that Mr. Colman experiments on a small scale 
