An entirely non-toxic
method for insect control in buildings involves the use of heat as a control
agent. It has been known for some time that insects are intolerant of
temperature changes which extend beyond a relatively narrow range.
Work carried out in the 1930s by the British ecologist Kenneth Mellanby showed that 100% mortality of human body lice occurred at 46.6oC for one hour. Green bottle flies were similarly killed at 43.3oC for one hour. The length of exposure, temperature and humidity are all factors which interact to determine whether and when an insect will die. Now some pest control companies in the US have developed commercially applicable systems for ridding domestic and other buildings of insect infestations. Any insects can be destroyed by heat treatment, but the system has been most frequently and effectively used against termite infestation of structural timbers, cockroaches, fleas, ants and other insects which tend to live or nest in inaccessible places. The heat treatment system works by covering the building to be treated with a tarpaulin and pumping in heated air from gas fuelled heaters. The aim is to raise all parts of the building to a temperature of 48.9oC and hold the temperature for at least 30 minutes. Heat treatment has many advantages over the use of chemicals in similar situations. It is entirely non-toxic to people and the environment, and the building can be re-inhabited immediately following treatment which is not always the case with chemical treatments. Heat treatment has also successfully cleared buildings of unpleasant odours and even sick building syndrome
The IPM Practitioner, XV(2), February
1994, Contact: Bio-Integral Resource Center, (BIRC), PO Box 7414, Berkeley, CA
94707, US, Tel: +1 510 524 2567.
[This article first appeared in Pesticides News No. 23, March 1994, page 19]