ENTOMOLOGY

Pyrethrwm PowderCOCKROACHES 381A safer, and sometimeo as e1l'ective, fumigant is pyrethrum powderburned in infested quarters. The only precautions here needed is to seethat the places under fumigation are tightly closed.SulphurFumigation for a period of six hours with fumes created by burningsulphur, four pounds per 1,000 cubic feet of space, is also recommendedfor the extermination of roaches. There are other substances possessingsome value as fumigants but the above-mentioned materials comprise themost promising of them.PoisonsIn cases of moderate infestation, or occurrence in situations inconvenientfor fumigation, some one of several substances poisonous toroaches can be employed. Our household species, however, especiallythe alert Croton bug, are not always easily persuaded to partake ofpoisoned food, as they appear to possess an uncanny knowledge of whatmaterials are unhealthy for them 'to eat. In their ability to look out forthemselves, and foil the attempts of man to destroy them, they have beencompared to that wily bird, the crow. But in spite of their intelligencein avoiding pitfalls set in their way, they are more or less subject tocontrol by various poisons and repellents.Sodium FloorideThis material has but recently come into prominence as a roachexterminator, but it is very surely the best remedy in the way of poisonsnow known. This powder probably kills both by contact and certainlyas an internal poison, and by its use an infested apartment may be sooncomphitely cleared of roaches. It is used either pure or diluted with onehalfpart flour or some other such substance. It is not injurious to manunless taken in considerable quantities and thus its use is not attended withdanger. The powder is scattered about the haunts of. roaches and blowninto cracks and crannies occupied by them with a dust gun, or blower.Boratl!Powdered borax, used pure a's a repellent, or mixed with some substanceattractive to roaches as a poison, is an e1l'ective remedy in manycases. One part of borax to three parts of pulverized chocolate is saidto be a good mixture.