Factors on Intra-Host Preference of the Larvae of the Onion Fly, Hylemya antiqua MEIGEN (Diptera : Anthomyiidae)

The larvae of the onion fly is known to prefer to feed on the roots and stem of the onion bulb, but the factors affecting this behavior are not known. In this study, the preference of the larvae for the stem and the base of the leaf was reconfirmed. The larval feeding preference on tissue was found to be correlative with the larval olfactory attractivity of the tissue. On the other hand, larval feeding response was not significantly different between the methanolic extract of the upper half of the outer leaf and the innermost embryonic leaves and stem. These suggest that the larvae of the onion fly select the stem and embryonic leaves mainly by olfactory cues.