THE BEDBUG. 15 



ing for a considerable period, all eggs and the young, and possibly most 

 if not all of the adults, would be exterminated. This method of 

 control might perhaps be practicable at least ui the case of summer 

 houses in the north which are left untenanted in the winter. 



The maintaining of high temperatures may be an even more effi- 

 cient method of control. The activity of the bedbug is at its greatest 

 between 60° and 70° to 75°. As indicated elsewhere, in a tempera- 

 ture of 96° to 100° F., accompanied with a high degree of humidity, 

 newly hatched bedbugs perish within a few days, and, if this tem- 

 perature is raised to 113° F., in a few minutes. A temperature of 

 113° will also destroy the eggs, and with these higher temperatures 

 the item of humidity is not apparently important. 



A very practical test of this method of control was made in 

 Ontario, Canada, by the Dominion Entomological Department,* 

 adapting the method of control of insects infesting granaries and 

 flour mills by superheating. In this instance an eight-room, tv/o- 

 story frame house, badly mfested with bedbugs, was during the month 

 of Jul}^ brought to a very high degree of heat by making up good 

 fires in the heating furnace and other stoves in the house and closing 

 up the house to retain the heat. Recording thermometers placed in 

 different rooms indicated a gradual rise of temperature from 77° to 

 160° during the period from 9.30 in the morning to 7.30 in the even- 

 mg, the outside temperatures during the same period ranging from 

 64° to 73° F. At 1.30, when the temperature in the different rooms 

 ranged from 109° to 130°, many adults and immature forms had 

 already succumbed. By 4.30 the temperature was ranging from 127° 

 to 148° in different rooms, and all the insects were dead. The con- 

 tinuation of the experiment was on the supposition that it would 

 probably require a higher degree of temperature to destroy the eggs. 

 The eradication of the bedbug from this house was complete, and no 

 damage was done to the house or its contents. That the tempera- 

 tures ranged much higher than was necessary is indicated by the 

 temperature experiments referred to elsewhere, which indicated that 

 the eggs as well as larvae are destroyed within a few minutes at a 

 temperature of 113° F. The latter temperature was also sufficient 

 to destroy quickly the adults of fleas, cockroaches, and other insects. 

 It would seem, therefore, that superheating of houses in midsummer 

 to a temperature of 120° to 130° F. may prove to be one of the 

 simplest and most effective means of eradication of this and perhaps 

 other household pests. 



» Ross, W. A. Eradication of the Bedbug by Superheating. In Canadian Entomologist, vol. 48, No. 3, 

 pp. 74-'(6. 1916. 



