Influence of natural leaf shapes on oviposition in three phytophagous flies: a comparative study

Abstract

Host finding and acceptance in herbivorous insects involves multimodal perception of chemical and physical properties characteristic of the host plants. Simplified artificial leaves have been used to demonstrate the influence of leaf shape on oviposition of phytophagous flies (e.g. Harris & Miller, 1984; Roessingh & Städler, 1990). However, to our knowledge only one attempt has been made to expose the flies to precise copies of host and non-host leaves. Prokopy et al. (1983) recorded landings of cabbage root flies on imitations of real plants and concluded that leaf shape is insignificant compared to leaf area and colour. Yet, these authors did not assess oviposition, thereby excluding possible post-alighting effects. We investigated whether the previously detected preferences for particular simple geometrical shapes (e.g. for narrow vertical cylinders in the case of the onion fly) are analogously manifested in a more complex context that comes closer to a natural situation.