Preference induction and the benefits of floral resources for a facultative florivore
- The causes and consequences of flower feeding for facultative florivores are poorly understood. Several factors can influence host selection and may, by extension, influence host part selection. Two such factors cited for the facultative florivore, Liriomyza trifolii (Burgess), are the optimisation of adult performance and natal habitat preference induction (NHPI) – a change in preference for a habitat in response to cues associated with the natal habitat.
- In this study we compared the nutritive and physical qualities of leaves and petals of Gerbera jamesonii, measured the survival and fitness of adults flies reared on leaves, flowers or a mixed diet, and investigated the influence of NHPI on adult host part choice.
- Liriomyza trifolii exhibited more than 50% higher lifetime fecundity on a mixed diet than on strict diets of leaves or flowers. Newly emerged adult flies exposed to leaves for 24 h showed a significant preference towards leaves, while flower-exposed flies showed no significant preference; flower-exposed flies were thus more than twice as likely as leaf-exposed flies to feed and oviposit on flowers.
- These results suggest that the optimisation of adult performance may be driving facultative florivory for L. trifolii in general, but the degree of florivory expressed is influenced by early adult experience, as NHPI explained 33% and 39% of feeding and oviposition host part choice, respectively. The potential for NHPI to influence the spatiotemporal occurrence of florivory is discussed.