The role of plant odours in the leafminer Liriomyza sativae (Diptera: Agromyzidae) and its parasitoid Diglyphus isaea (Hymenoptera: Eulophidae):: Orientation towards the host habitat

Electroantermogram responses of the polyphagous leafminer Liriomyza sativae and its generalist parasitoid Diglyphus isaea to host and non-host plant odours of L. sativae were investigated. The odours of healthy leaves can elicit distinct EAG responses in L. sativae. The EAG responses to the odours of the host plants, bean and tomato, were stronger than to non-host plants, Chinese rose and morning glory. Neither healthy host nor non-host plants of the leafminer elicited distinctive EAG responses in the parasitoid, D. isaea. Odours of physically damaged leaves, no matter whether of host or non-host plants, increased strongly the EAG responses of the leafminer and its parasitoid. We compared the EAG responses of D. isaea to bean leaves of different status. The odour of mined leaves elicited distinct EAG responses, which were weaker than those of physically damaged ones. No differences were detected in the EAG response to leaves with empty mines, healthy leaves or an air control. The role of plant odours in host location of the leafminer and its parasitoid is discussed.