Tritrophic interactions between the leaf miner, liriomyza bryoniae (kaltenbach) (diptera: agromyzidae) and the parasitoid, diglyphus isaea (walker) (hymenoptera: eulophidae)

摘要

Liriomyza bryoniae is an economically important pest of vegetable and ornamental crops in European glasshouse agriculture. Diglyphus isaea is a parasitoid of Liriomyza leaf miners and is commercially available as a biological control agent. Anecdotal reports made to commercial producers of the parasitoid suggest that the efficacy of D. isaea varies between crops. This study examines the tritrophic interactions between crop plant, L. bryoniae and D. isaea.ududHost plant was found to influence the abundance of L. bryoniae and D. isaea with larger populations establishing in the culturing host than in the novel host, tomato. Individual size of L. bryoniae also varies with host plant. These patterns are consistent in L. bryoniae across three generations of rearing on tomato. Habituation of L. bryoniae to tomato does not affect D. isaea efficacy nor does the natal plant host of D. isaea. Both L. bryoniae and D. isaea are affected by plant host ontogenetic stage, becoming most numerous on juvenile plants. The D. isaea natal insect-plant complex showed no effect on D. isaea olfactory preferences. Diglyphus isaea demonstrated greater thermal tolerance than its host. These results are discussed in relation to biological control and also in terms of their wider ecological implications.ud