6 



FARMERS BULLETIN 



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 



Fig. 3.— Bedbug: Egg and newly hatched larva: a, Lar\a from below; b, larva from above; c, claw; 

 d, egg; c, hair or spine of larva. Greatlj- enlarged, natural size of larva and egg indicated by hair lines. 

 (Author's illustration.) 



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 temper- 

 ature and food it was found that there was an average period of about 

 eight days between meltings and between the laying of eggs and 

 their hatcliing, givmg about seven weeks as the period under these 



Fig. 4.— Bedbug: a, Larval skin .shed at first molt; 6, second larval stage immediately after emerging from 

 a; c. same after first meal, distended with blood. Greatly enlarged. (Author's illustration.) 



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, lender con- 

 ditions of famine, or without food, as already shown, the bedbug may 

 remain unchanged in anv of the immature stages for an indefinite 



