Flower attractiveness and fitness effects on a dipteran pest and its parasitoids for conservation biological control
Description
Flower addition is commonly used worldwide to benefit parasitoids and improve conservation biological control of pests. However, biological control enhancement via flower addition depends on the responses of both parasitoid and pest species to flower resources and on flower attractiveness. Here, we experimentally evaluated the effects of two Apiaceae flowering species (Conium maculatum and Coriandrum sativum) with respect to those of water, honey and no resource treatments on longevity and survival of the leafminer Liriomyza huidobrensis adults and two himenopteran parasitoids (Chrysocharis flacilla and Phaedrotoma scabriventris. We also examined the attractiveness of both flower species to the leafminer and one of the parasitoid species. Consumption of flower resources increased longevity and survival of the three insect species with respect to water and no resource treatments. Honey effects on longevity were similar to or even higher than those of flowers, depending on the insect species, whereas water only increased the longevity of P. scabriventris in relation to no resource treatments. In attractiveness trials, parasitoids, but not leafminers, preferred C. maculatum flowers. Our findings indicate both plant species have potential as floral resources in biological control since two parasitoids species benefited from flowers. However, these flowering species must be cautiously considered because L. huidobrensis also improved its fitness when provided with both floral resources. The present work highlights the need to simultaneously study parasitoid and herbivore food needs and flower attractiveness, especially in dipteran pests, in order to achieve a successful biological control.