Author
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Alverson, Janet |
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Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/12/2002 Publication Date: N/A Citation: N/A Interpretive Summary: Problems associated with conventional pesticides have prompted efforts to use biologically based techniques. Such technologies, which include biological control by augmentation and sterile insect technology, require mass rearing of insects. However, microbial contamination is a serious problem affecting the rearing of insects. Aspergillus niger, a mold common in the environment, is especially persistent and can be difficult to manage once established in the insectary. Scrupulous sanitation methods must be employed in the rearing facility, especially during artificial diet production and handling, to prevent the mold from contaminating the insect colony. The effects of this mold contamination on the Western tarnished plant bug, Lygus hesperus, were tested by experimentally inoculating an artificial diet used to rear the insects. The inoculum used mimicked the scenario of an accidental lapse in sterile technique in diet preparation. The insects showed a dramatic decrease in quality, especially in egg production and death of young insects. This research is of benefit to the growing insect rearing community (commercial and government-based) in emphasizing the need for proper sanitation as Standard Operating Procedure in the insectary. Technical Abstract: The effect of Aspergillus niger contaminated artificial diet on Lygus hesperus Knight (Heteroptera: Miridae) is described. A standard number of A. niger spores was inoculated into an artificial diet used to rear L. hesperus, and the effect on biological fitness of the insect was measured. Biological fitness was defined as total number of surviving adults, mean biomass (dry weight) accumulated per cage over the total test period, egg production, time to adult emergence, and time to the beginning of egg laying. These measurements were all significantly different for insects reared on the inoculated diet from those reared on the control diet. The insects reared on the diet inoculated with A. niger showed a high mortality of nymphs, a decrease in mean biomass, delayed development time, and a decrease in egg production. This study demonstrates the devastating effect A. niger diet contamination can have on a laboratory colony of L. hesperus, and emphasizes the need for constant vigilance and adherence to strict sanitation methods in an insect rearing facility. |
