MEDITERRANEAN MILL OR FLOUR MOTH. 105 
During the past year information was sent, as before, with regard 
to the great trouble caused by this infestation as a mill pest, and 
more observation than I had previously received of it occurring (and 
not thought of at all in the light of getting rid of it) in neglected 
corners of bakers’ flour stores. 
No further information, however, was contributed as to remedial 
measures beyond those already known, of turning on hot steam, and 
also fumigating with sulphur, &c., which, though beneficial in clearing 
the pests, may in some cases do so much harm to the outside of the 
flour within sacks left exposed to the fumigation, that this treatment 
requires great care. The attack and remedies have been gone into at 
great length in my Twelfth, Thirteenth, Fourteenth, and Fifteenth 
Annual Reports. 
But in the past year, whilst collecting illustrations of economic 
entomology for exhibition at the show of the Bath and West of 
England Society at St. Albans, a piece of felted-up flour was sent me 
which gave an interesting example of the length of time in which 
successive generations would appear out of one small mass of flour, 
and the amount of multiplication. 
The specimen of flour was received by me in the autumn of 1895, 
on or about October 7th, and I placed it in a box twelve inches by 
eight, and two and a half inches deep, with a glass top, so as to allow 
of observation, and so specially made that the caterpillars could not 
escape. Only a very little infestation was noticeable on receipt, and 
the first caterpillar spun up on October 13th. The box stood on a 
side table in my study, where the temperature was of the ordinary 
warmth of sitting-rooms, and where it could always be under observa- 
tion during the winter; the moths continuing to make their appearance 
until, on April 6th, there were, on careful counting, approximately, 
four hundred in the box. Of these many had died, but some were 
living, apparently in excellent health, and the plumage of their wings 
in such good unrubbed condition that it showed they had very lately 
come out of their chrysalis-cases, and this, together with the presence 
of the live caterpillars and chrysalids, showing that multiplication 
was still going on. 
The flour was now felted together by the caterpillars’ threads into 
a mass ten inches long by six inches wide, forming a layer of variable 
thickness up to about an inch in the thickest part. The whole mass 
webbed firmly together throughout, and also webbed to the paper on 
which it was placed at the bottom of the box. 
On April 14th the box was accidentally let fall on a wooden floor 
with such a sharp jar that the mass of felted-together flour was 
loosened from its webbings at the bottom of the box, and in a very 
short time I saw two nearly full-grown caterpillars and one about a 
