Beykk: Trogoderma inclisa. 383 



the insects, I raised the temperature to 120 degrees, and then the 

 insects were removed and pUiced in an incubator and given a chance 

 to recover, but the test showed finally that they were all dead. I 

 repeated the experiment a number of times, and found that as soon 

 as a temperature of from 119 to 120 degrees was recorded it proved 

 fatal to all stages of the insect. It required about thirty minutes 

 to reach this temperature. 



In a second series of experiments I continued to use the dry-heat 

 oven, again raising the temperature to 86 degrees. I then took one 

 of the infested horse collars and made a hole in the leather, through 

 whicli I inserted the bulb of a thermometer into the interior of the 

 stuffing. The collar was then placed in the oven on an asbestos floor 

 to allow equal heating. The temperature was gradually raised to 

 120 degrees, which took about ten hours. After leaving the collar 

 in the oven for a period of ten hours it was removed and placed in 

 the incubator to allow a chance for the insects to develop again. A 

 day or two following I removed the collar and proceeded to make 

 a thorough dissection of it. I found that the larvae and adults were 

 all dead. Upon further incubation of the straw stuffing it was found 

 that the eggs had also been destroyed by the maximum temperature, 

 as no more of the insects were hatched. 



After demonstrating in the laboratory by experiments that this 

 species of insect could be destroyed at a temperature below that 

 which would be injurious to the leather of the horse collars, steps 

 were taken to test out its results as to the practibility in a seriously 

 infested collar factory overrun with Trogaderma inclusa, of the 

 results which were demonstrated in the laboratory. 



The means of extermination was left in the hands of the experi- 

 menter. The collar warehouse w^as the only infested floor, and it 

 was located on the sixth floor of the factory. The heating facilities 

 were too inadequate to produce the temperature required to ex- 

 terminate the infestation; hence, according to instruction, a small 

 room, twelve feet long, eight wade and twelve high, was constructed, 

 and lined on the interior with asbestos. Two large steam-heat radi- 

 ators were installed, and the collars hung on brackets about the 

 room. One large thermometer was placed in the room and several 

 smaller ones inserted in the collars. The results of this work proved 

 successful. 



In this experiment also two thermometers were employed. One 

 was placed in a collar and the other in the chamber. By recording 

 the temperatures at short intervals and plotting them on a chart, 



