36 PRINCIPAL HOUSEHOLD INSECTS. 



wood {Populns monilifera), especially along the Big- and Little Horn 

 rivers in Montana. 



The origin of this misconception — for such it is— so far as the out-of- 

 door occurrence is concerned, is probably, as pointed out by Professor 

 Eiley, from a confusion of the bedbug with the immature stages of an 

 entirely distinct insect {Aradus si).) which somewhat resembles the 

 former and often occurs under cottonwood bark. In houses, green or 

 moist cottonwood logs or lumber may actually furnish sustenance in 

 the absence of human food. The bedbug is, however, known to be 

 able to survive for long periods without food, specimens having been 

 kept for a year in a sealed vial, with absolutely no means of sustenance 

 whatever, and in unoccupied houses it can undoubtedly undergo fasts 

 of extreme length. Individuals obtained from eggs have been kept 

 in small sealed vials in this office for several months, remaining active 

 and sprightly in spite of the fact that they had never taken any nour- 

 ishment whatever. 



Extraordinary stories are current of the remarkable intelligence of 

 this insect in circumventing various eftbrts to prevent its gaining access 

 to beds. Most of these are undoubtedly exaggerations, but the inher- 

 ited experience of many centuries of comj^anionship Avith man, during 

 which the bedbug has always found its host an active enemy, has 

 resulted in a knowledge of the habits of the human animal and a facil- 

 ity of concealment, particularly as evidenced by its abandoning beds 

 and going often to distant quarters for protection and hiding during 

 daylight, which indicate considerable ai)parent intelligence. 



The bite of the bedbug is decidedly poisonous to some individuals, 

 resulting in a slight swelling and disagreeable inflammation. To such 

 persons the presence of bedbugs is sufficient to cause the greatest 

 uneasiness, if not to put sleep and rest entirely out of the question. 

 With others, however, who are less sensitive, the x)resence of the bugs 

 may not be recognized at all, and, except for the occasional staining of 

 the linen by a crushed individual, their presence might be entirely 

 overlooked. The inflammation experienced by sensitive persons seems 

 to result merely from the jmncture of the skin by the sharp piercing 

 setie which constitute the puncturing element of the mouth parts, as 

 there seems to be no secretion of poison other than the natural fluids 

 of the mouth. 



The biting organ of the bedbug is exactly like that of other hemip- 

 terous insects. It consists of a rather heavy, fleshy under lip (the only 

 part ordinarily seen in examining the insect), within which lie four 

 thread-like hard filaments or setie which glide over each other with 

 an alternating motion and pierce the flesh. The blood is drawn up 

 through the beak, which is closely applied to the i^oint of puncture, 

 and the alternating motion of these setie in the flesh causes the blood 

 to flow more freely. The details of the structure of the beak are shown 

 in the accompanying sketch (fig. 7, d). In common with other insects 



