Potential for host range expansion in Ceratitis capitata flies: impact of proximity of adult food to egg‐laying sites

Abstract

Abstract. In field cage and field tests, female Mediterranean fruit flies, Ceratitis capitata (Wiedemann), in trees alighted in significantly greater numbers upon sticky‐coated (non‐odour‐emitting) kumquats, Fortunella japonica, that were in the vicinity of odorous natural proteinaceous food (bird faeces) or synthetic food odour than on similar kumquats distant from bird faeces or synthetic food odour. In field cage tests, oviposition in non‐sticky kumquats nearby bird faeces was significantly greater than in non‐sticky kumquats distant from bird faeces. In field tests, medflies laid significantly more eggs in host kumquat and non‐host hawthorn, Crataegus mollis, fruit adjacent to bird faeces and synthetic food odour than in fruit of these types distant from food‐type stimuli. These findings suggest that odour of natural food of medflies could lure flies to plants whose fruit emit little or no attractive odour and are not permanent hosts but which are nonetheless susceptible to egg‐laying and larval development, resulting in temporary expansion of host range.