The Bed-bugs 89 



69.9 days; average number of meals 8.75 and the molts 5. Under 

 conditions allowing about half the normal food supply the average 

 nymphal life was from 116.9 to 139 days. Nymphs starved from 

 birth lived up to 42 days. We have kept unfed nymphs, of the first 

 stage, alive in a bottle for 75 days. The interesting fact was brought 

 out that under these conditions of minimum food supply there were 

 sometimes six molts instead of the normal number. 



The adults are remarkable for their longevity, a factor which is 

 of importance in considering the spread of the insect and methods of 

 control. Dufour (1833) (not De Geer, as often stated) kept speci- 

 mens for a year, in a closed vial, without food. This ability, coupled 

 with their willingness to feed upon mice, bats, and other small mam- 

 mals, and even upon birds, accounts for the long periods that deserted 

 houses and camps may remain infested. There is no evidence that 

 under such conditions they are able to subsist on the starch of the 

 wall paper, juices of moistened wood, or the moisture in the accumu- 

 lations of dust, as is often stated. 



There are three or four generations a year, as Girault's breeding 

 experiments have conclusively shown. He found that the bed-bug 

 does not hibernate where the conditions are such as to allow it to 

 breed and that breeding is continuous unless interrupted by the lack 

 of food or, during the winter, by low temperature. 



Bed-bugs ordinarily crawl from their hiding places and attack 

 the face and neck or uncovered parts of the legs and arms of their 

 victims. If undisturbed, they will feed to repletion. We have 

 found that the young nymph would glut itself in about six minutes, 

 though some individuals fed continuously for nine minutes, while 

 the adult required ten to fifteen minutes for a full meal. When 

 gorged, it quickly retreats to a crack or crevice to digest its meal, 

 a process which requires two or three days. The effect of the bite 

 depends very greatly on the susceptibility of the individual attacked. 

 Some persons are so little affected that they may be wholly ignorant 

 of the presence of a large number of bugs. Usually the bite produces 

 a small hard swelling, or wheal, whitish in color. It may even be 

 accompanied by an edema and a disagreeable inflammation, and in 

 such susceptible individuals the restlessness and loss of sleep due to 

 the presence of the insects may be a matter of considerable im- 

 portance. Stiles (1907) records the case of a young man who under- 

 went treatment for neurasthenia, the diagnosis being agreed upon by 

 several prominent physicians; all symptoms promptly disappeared, 



