Effect of temperature and humidity onTrogoderma anthrenoides(Sharp)(Coleoptera, Dermestidae) and comparisons with related species

Abstract

The egg production and development ofTrogoderma anthrenoides(Sharp) has been studied over a range of temperatures from 17·5 to 37·5°C. and in relative humidities of 70 per cent, and near 0 per cent.At 70 per cent. R.H., the minimal temperature for development was between 17·5 and 20°C. and the maximum between 35 and 37·5°C. Adult females, which apparently required no food, lived on average 18 days at 37·5°C., this period increasing with falling temperature to 146 days at 17·5°C. The greatest number of eggs, a mean of 54 per female present, were laid at 27·5°C. The quickest development occurred at 35°C., females taking a mean of 44.7 days (egg 6; larva 34·3; pupa 4·4). Male larvae developed slightly faster and male adults died a little earlier than females.Near-zero humidity shortened adult life, reduced egg production and prevented the development of larvae.Some larvae entered a condition that is probably a facultative diapause resembling that ofT. parabileBeal. The diapause was terminated by an increase in volume of food combined with a change of temperature.The biology ofT. anthrcnoidesresembles that of two minor pests,T. parabileandT. inclusumLee., more than that of the important pestT. granariumEverts. The first two species show no signs of becoming serious pests. It is concluded thatT. anthrcnoidesprobably has the potential only of a minor pest.