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THE Reaction of the kola weevil, sophrorhinus gbanjaensis to moisture
- DARAMOLA, AJIBOLA M.
- Entomologia experimentalis et applicata 1976 pp. 248-260
- Curculionidae, air, females, insects, males, mortality, relative humidity
- The reaction of the kola weevil, Sophrorhinus gbanjaensis to moisture in a simple and a two-way gradient (centre low, high at ends) and a humidity choice chamber and its survival at the different relative humidities of 10, 30, 60, 80 and 95% R.H. were investigated. Both the male and female insects showed preference for the dry air (10 & 30% RH) in the humidity gradient irrespective of its position along the gradient. The insects also detected and reacted to humidity differences of 20 & 30% RH when offered a choice of 40-60%; 0-30%; 60-100%; 10-60% and 50-100% relative humidities. The indices of reaction (IR) increased with increase in the differences between the pairs of humidities offered with a peak at 60-100% and 50-100% RH for males and females respectively. The insects survived for an average of 21.1 ± 1.3 days and 5.4 ± 0.2 days at 95% and 10% RH respectively. A highly significant negative correlation (r= −0.926) was obtained between the mortality rates of the insects and the various relative humidities.