Reactions of the Corn Borer Ch. Agamemnonbles, Towards Some Physical Factors

[1. The third instar larvae of the corn borer Chilo agamemnon Bles. were sensitive to small temperature differences of 1-2°C above 35°C in an alternative chamber, where a strong avoiding reaction to the warmer side was observed. The prefered zone of temperature was between 25-25°C and the linear velocity of the larvae increased proportionally with the temperature increase between 15 and 35°C. 2. The larvae always prefered high humidities and the average reaction intensity progressively increased with increase in the difference between the two alternative humidities in the arena. 3. The larvae were photonegative. The lateral ocelli served as photoreceptors by means of which the larvae sum up the light from various directions and moved in a path influenced by the more intense light and deviating towards the low intensity beam (tropotaxis). The larval reactions towards dark objects was skototactic. 4. Orthokinesis, klinokinesis and klinotaxis were the main mechanisms regulating the larval behaviour towards temperature, humidity and light. 5. The reactions towards two or three combined variable factors at the same time show that both temperature and relative humidity probably affect the behaviour of the larvae more than light. 6. 'The larval behaviour and its correlation to the normal environment was also discussed., 1. The third instar larvae of the corn borer Chilo agamemnon Bles. were sensitive to small temperature differences of 1-2°C above 35°C in an alternative chamber, where a strong avoiding reaction to the warmer side was observed. The prefered zone of temperature was between 25-25°C and the linear velocity of the larvae increased proportionally with the temperature increase between 15 and 35°C. 2. The larvae always prefered high humidities and the average reaction intensity progressively increased with increase in the difference between the two alternative humidities in the arena. 3. The larvae were photonegative. The lateral ocelli served as photoreceptors by means of which the larvae sum up the light from various directions and moved in a path influenced by the more intense light and deviating towards the low intensity beam (tropotaxis). The larval reactions towards dark objects was skototactic. 4. Orthokinesis, klinokinesis and klinotaxis were the main mechanisms regulating the larval behaviour towards temperature, humidity and light. 5. The reactions towards two or three combined variable factors at the same time show that both temperature and relative humidity probably affect the behaviour of the larvae more than light. 6. 'The larval behaviour and its correlation to the normal environment was also discussed.]