8 FARMERS BULLETIN 754. 



series of experiments was later conducted by Girault/ bearing on the 

 longevity of the insect under different conditions. A large number 

 of adults of both sexes were kept in confinement, but with normal 

 feeding and mating, and these survived for periods ranging from 54 

 to 316 days. Similarly, the life of 71 newly hatched larvae, without 

 food, ranged from 17 to 42 days, averaging about 28 days. Partly 

 grown captured insects hved without further feeding from 17 to 60 

 days. Longevity is naturally affected more or less by temperatures. 

 In other words, temperatures sufTicient to check the activity of the 

 insect and produce hibernation or semihibernation are apt to increase 

 longevity. 



The fact that the bedbug is able to survive for such long periods 

 without human blood has led to the theory that it could subsist in 

 some fashion on the moisture from wood or from accumulations of 

 dust in crevices in flooring, etc. There seems to be no basis of 

 observed fact for this idea. 



Another very prevalent belief among the old settlers in the West, 

 that this insect normally lives on dead or diseased cottonwood logs, 

 and is almost certain to abound in log houses of this wood, seems to 

 be equally devoid of basis. As illustrating this belief, the depart- 

 ment has on file a very definite report from an Army officer that the 

 bedbug often occurs in numbers under the bark of dead cottonwood 

 trees,^ especially along the Big Horn and Little Horn Rivers in 

 Montana. The basis of this report and the origin of this very general 

 misconception is probably, as pointed out by the late Prof. Riley, 

 due to a confusion of the bedbug with the immature stages of an 

 entirely distinct insect,^ which somewhat resembles the bedbug and 

 often occurs under cottonwood bark. 



INFLUENCE OF TEMPERATURE. 



As a messmate of human beings in dwelling houses, the bedbug is 

 normally protected from extreme cold, and is known to be an 

 abundant and serious pest far north. In fact, it is often more 

 troublesome in north temperate latitudes than farther south. This 

 may be accounted for partly by the fact that the bedbug is very 

 sensitive to high temperatures, and a temperature of 96° to 100° F. 

 or more, accompanied with a fairly high degree of humidity, results 

 in the death of large numbers of the bugs. The mature or partly 

 mature bedbugs can stand comparatively low temperatures, even 

 below freezing, for a considerable period. The eggs and newly 

 hatched larvjie, however, succumb to a temperature below freezing, 

 if this condition is prolonged for from 15 days to a month. The 

 feeding and developing activity of the insect practically ceases at 

 60° F., the insect remaining quiescent and in semiliibernation at 



1 T.oc. cit. 2 Populus monilif(ra. ^ A mdux sp. 



