‘Tue Conrusep Fiour BEETLE 75 
‘hey were placed in flour and kept at a temperature of 26°C. and in an 
atmosphere of about 70 per cent of relative humidity. The number of 
larvae found after various periods of time were recorded and used as an 
index of fecundity. The eggs are so difficult to distinguish when 
coated with flour that it has been found that a count of the larvae is 
more accurate than one of the eggs. There may be an error due to 
eggs which do not hatch and larvae which may die while very small and 
are overlooked in the count. After 42 days the ten pairs of adults 
had produced the following numbers of larvae: Ist, 41; 2nd, 23; 3rd, 
20% 4th, 32> 5th, 50; 6th, 45; 7th, 12; Sth, 7; 9th, 7; 10th, male died, no 
larvae. 
Some of the eggs are deposited on the sides or bottom of the con- 
tainer but the majority are deposited in the flour or cereal itself. Ina 
small quantity of flour which had been exposed to beetles, 263 eggs were 
found, 8 of which were adhering to the sides of the container, 15 to the 
bottom, and the remainder were found by sifting the flour. In this 
case the error from overlooking eggs in the sifted flour would be much 
greater than that from overlooking eggs on the sides or bottom of the 
container, which was of glass. 
Upon hatching, the young larvae moult, for the first time, in about 
24 hours. The posterior end of the larva adheres to the eggshell for 
some time after hatching and the shell may be dragged about by the 
larva, if it is at the surface of the flour. In this case the larva may free 
itself only when it moults, leaving the skin attached to the eggshell. 
During the first instar the larva is whitish, but a short time after the 
first moult it assumes a yellowish color. Perhaps the lack of color in 
the first instar is due to the short duration of this instar which does 
not permit the formation of a sufficient amount of chitin to give color 
to the larva. 
Fora short time before each moulting, the larva is inactive and the 
body is large in proportion to the head. The skin splits dorsally over 
the head and the thorax, and the larva emerges. It is at first white, 
like the larva of the first instar, but after twenty-four hours it takes 
on a yellowish color. Immediately after moulting, when the larva 
has expanded as a result of being freed from the old skin, it has often 
been observed to remain quiet for a time. When examined in favorable 
light during this time of quiet, one may see small bubbles of air passing 
in through the oesophagus and back into the proventriculus. The ap- 
parent passiveness of the larva makes it appear as if the air were drawn 
in by suction as the body expands. The bubbles of air are retained and 
may be observed in larvae of almost any age. 
