Location: Biological Control of Pests Research2013 Annual Report
1a. Objectives (from AD-416):
The long-term objective of this project is to develop an improved understanding of the biology, nutrition, and behavior of natural enemies of pest arthropods. Our primary target pest will be the two-spotted spider mite, Tetranychus urticae. Some of the most important natural enemies of this mite are phytoseiid predatory mites and coccinellids. We aim to implement, improve and increase the mass rearing capabilities of these organisms by developing artificial diets and novel rearing technology to enable economical biological control of this pest by augmentation of its natural enemies and to develop novel techniques of quality control and quality assurance. Our work will focus on the following: (1) Determine nutritional, behavioral, and physical conditions necessary for in vivo and in vitro insect rearing and use the results to implement mass production systems of biological control agents. (2) Determine the impact of mass rearing procedures on survival, reproduction, and gene expression. (3) Assess optimal conditioning of insects for release.
1b. Approach (from AD-416):
Research activities will focus on a specific predator, Stethorus punctillum and a generalistic predator, Coleomegilla (C.) maculata. Studying the nutritional requirements of a generalist versus a specific predator will provide insights on diet development of these 2 organisms. The generalist predator is expected to be an easier target for artificial diet development and success will have greater impact since C. maculate is an important predator of several economically damaging pest species.
3. Progress Report:
Research on development of artificial diets for the pink spotted lady beetle, Coleomegila (C.) maculata, yielded three new formulations using new ingredients recently coming into the market. These new diet formulations have shown promise by reducing development time and increasing adult size and evaluation of the new formulations is under way. Efforts to identify factitious food for the pink spotted lady beetle have yielded promising results using a mixture of eggs of the brine shrimp (Artemia franciscana) and of a powdered freshwater algae (Chlorella vulgaris). While the use of factitious food is more complicated and expensive than an artificial diet, it provides significant economic advantages over the state of the art rearing based on eggs from the Mediterranean flour moth. New laboratory strains of the pink spotted lady beetle have been bred. These strains include visible marker strains with variable coloration and spot patterning. These strains will be useful for de novo sequencing, for dissecting biochemical pathways and for testing gene expression in stress conditions. Modifications of existing artificial diet formulations for C. maculata have been successfully tested on other predatory species including the insidious flower bug, Orius insidiosus, and the predatory mite, Amblyoseiulus swirskii. Both of these species are produced commercially in Europe and the U.S. and there is a current cooperative agreement on this research. On the production of the predatory mite, Phytoseiulus persimilis, a new diet encapsulation method and improved diet formulation have been developed as part of a Cooperative Research and Development Agreement. On the study of semiochemicals associated with lady beetles, work is in progress on the isolation and identification of compounds present in cedar trees (e.g., Juniperus virginiana L.) that might stimulate oviposition in the pink spotted lady beetle. A toxic alkaloids (myrrhine) previously reported as a defensive chemical present in the egg shells of several species of lady beetles, have been found present in the egg shells of the pink spotted lady beetle. On the in vivo production of insect killing (entomopathogenic) nematodes, a new diet has been developed to improve the production of the nematode host, the yellow mealworm (Tenebrio molitor). This diet was developed using insect self-selection by multiple-choice of predetermined diet formulations. This novel method has promise for refining existing predator diets without the need of long and costly trial and error tests. On the classic biological control efforts against invasive stink bugs, continuous cultures of 4 imported and 7 native wasp egg parasitoid species have been established in quarantine. These egg parasitoids are currently being tested for their effectiveness against the brown marmorated stink bug (Halyomorpha halys), the kudzu bug (Megacopta cribraria) and the bagrada bug (Bagrada hilaris). Production of these invasive stink bug species has been accomplished by the continuous availability of eggs from the spined soldier bug (Podisus maculiventris), which has been maintained successfully in culture using yellow mealworm pupae.
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. 21:83-92. doi:10.1111/1744-7917.12033.