Bioassay approaches to observing behavioural responses of adult female Cydia molesta to host plant odour

Abstract:  Three different olfactometers were evaluated in order to develop a bioassay procedure testing for the olfactory responses of Cydia molesta . Females were tested individually using a linear and a Y-tube olfactometer, and in groups using a dual-choice arena. Room temperature, relative humidity, light intensity, airflow, age of the moths and odour source were kept constant during experiments. The odour source tested was a green shoot of peach excised 10 min before experiments started. Cydia molesta females showed a significant response to this plant odour in all olfactometers. A number of qualitative aspects were found to be in favour of the dual choice arena as a tool for screening potentially attractive odour sources. It allowed for a differentiation of the response of mated and virgin females. Experimental conditions allowed the circadian rhythm of insects to be mimicked. Manipulation of individuals is reduced and flight is not precluded.