[5] Girault, A. A. Preliminary studies on the biology of the bedbug, _Cimex lectularius_, Linn. III. Facts obtained concerning the habits of the adult. _In_ Jour. Econ. Biol., v. 9, no. 1, p. 25-45. 1914. The eggs hatch in a week or 10 days in the hot weather of midsummer, but cold may lengthen or even double this egg period or check development altogether. The young escape by pushing up the lid-like top with its projecting rim. When first emerged (fig. 3, _a, b_) they are yellowish white and nearly transparent, the brown color of the more mature insect increasing with the later molts (fig. 4). [Illustration: Fig. 3.--Bedbug: Egg and newly hatched larva: _a_, Larva from below; _b_, larva from above; _c_, claw; _d_, egg; _c_, hair or spine of larva. Greatly enlarged, natural size of larva and egg indicated by hair lines. (Author's illustration.)] [Illustration: Fig. 4.--Bedbug: _a_, Larval skin shed at first molt; _b_, second larval stage immediately after emerging from _a_; _c_, same after first meal, distended with blood. Greatly enlarged. (Author's illustration.)] During the course of its development the bedbug molts or sheds its skin normally five times, and with the last molt the minute wing pads, characteristic of the adult insect, make their appearance. A period of about 11 weeks was formerly supposed to be necessary for the complete maturity of the insect, but breeding experiments with this insect, conducted in this department in. 1896, indicated that the life cycle is subject to great variation, being entirely dependent on warmth and food supply. Under favorable conditions of temperature and food it was found that there was an average period of about eight days between moltings and between the laying of eggs and their hatching, giving about seven weeks as the period under these conditions from egg to adult insect. The molting periods are shorter in the earlier stages and lengthen in the later stages. There are many exceptions, however, and some individuals even under the same conditions remain two or three weeks without molting. Under conditions of famine, or without food, as already shown, the bedbug may remain unchanged in any of the immature stages for an indefinite time, and the checking of development by such starvation may result in additional molting periods.