Title: Is Tetranychus urticae suitable prey for development and reproduction of the naive Coleomegilla maculata? Authors
Submitted to: Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 8, 2013
Publication Date: June 22, 2013
Citation: Riddick, E.W., Wu, Z., Rojas, M.G. 2013. Is Tetranychus urticae suitable prey for development and reproduction of the naive Coleomegilla maculata?. Insect Science. doi:10.1111/1744-7917.12033. Interpretive Summary: In our vision of reducing pesticide usage on crops and promoting augmentative biological control of crop pests, we are exploring the potential of using native predators to suppress spider mite populations. The two-spotted spider mite Tetranychus urticae is a serious pest of plants in greenhouses, plantscapes, and in crop fields. We are currently studying lady beetles as predators of spider mites and developing techniques to rear lady beetles more cost effectively. We designed experiments to determine if lady beetles could develop and reproduce normally when feeding on spider mites in laboratory arenas. We discovered that the lady beetle Coleomegilla maculata readily attacked and consumed the two-spotted spider mite. However, spider mite does not support its optimal growth, development or reproduction. Interestingly, adding a powdered mixture of synthetic pollen and an alga in arenas enabled predators to develop and reproduce successfully on nutrient-poor spider mite. This new knowledge informs us that some lady beetles can compensate for nutrient poor prey by consuming plant products. Using pollen and algae as supplemental food for predators in the field (greenhouse, plantscape) might increase the time that immature and adult stages remain active on crop plants. Greater suppression of spider mites could result without an increase in pesticide usage. ----
Technical Abstract: The lady beetle Coleomegilla maculata De Geer is an omnivorous predator of arthropod pests in agricultural landscapes. We envision the mass production of C. maculata by the biocontrol industry to suppress aphid and spider mite populations on plants in greenhouses, plantscapes or interiorscapes. Our research is assessing the nutritional requirements and feeding behavior/ecology of this predator on target prey, factitious food, and insect-free artificial diets. In this study, we tested the hypothesis that two-spotted spider mite Tetranychus urticae Koch is satisfactory prey for development and reproduction of C. maculata. We reared predator larvae and adults in groups (rather than singly) in Petri dish arenas. Although predators readily accept and consume two-spotted spider mite, this prey negatively affects development and reproduction. In comparison to common house fly Musca domestica L. or Mediterranean flour moth Ephestia kuehniella Zeller, two-spotted spider mite is unsatisfactory prey for C. maculata larvae and adults. However, applying a synthetic pollen-Chlorella alga powder (SPCA) in arenas containing spider mite enabled predators to develop and reproduce successfully. This study reports the novel use of a synthetic pollen-alga powder to supplement the nutritional content of unsatisfactory prey for a predatory lady beetle.