|Steinkraus, Donald - UNIVERSITY OF ARKANSAS|
Submitted to: Ecological Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 1, 2003
Publication Date: November 1, 2003
Citation: GEDEN, C.J., STEINKRAUS, D.C. EVALUATION OF THREE FORMULATIONS OF BEAUVERIA BASSIANA FOR CONTROL OF LESSER MEALWORM AND HIDE BEETLE IN GEORGIA POULTRY HOUSES. ECOLOGICAL ENTOMOLOGY. 2003. v.96(5).p. 1602-1607. Interpretive Summary: Lesser mealworm and hide beetles are the most important arthropod pests of the poultry industry throughout the world. Their pest status is three- fold. First, the beetles are reservoirs of human and avian diseases. Second, they are highly destructive structural pests that attack building construction materials. Third, they become public nuisance pests when they emigrate from poultry farms and invade the homes, schools, and businesses of nearby residents. Insecticides are not effective for controlling the beetles. In this study, scientists at USDA's Center for Medical, Agricultural and Veterinary Entomology and the University of Arkansas tested a fungal biocontrol agent (Beauveria bassiana) for beetle control in commercial poultry houses in Georgia. After screening 12 candidate strains of the fungus, two strains were grown in bulk and prepared in three different formulations. The products were applied to the esurface of the manure and beetle populations were monitored. None of the fungal treatments provided long-term beetle control, but the project's results demonstrated that dry bait formulations of the fungus were much more effective than a liquid spray.
Technical Abstract: Initial screening of 12 Beauveria bassiana isolates against larvae of the lesser mealworm (Alphitobius diaperinus[Panzer]) resulted in the selection of two isolates, GHA and 707, for further testing under field conditions. Three formulations of each strain prepared: an EC, a ground corn granular formulation, and waste product of fungal propagation containing spent media, myecelia, and unharvested conidia ("residue" formulation). Two field trials were conducted in commercial caged layer houses in Georgia with established populations of A. diaperinus and hide beetles (Dermestes maculatus DeGeer). In the first trial field, B. bassiana was applied a single time to the manure surface at rates of 10 to the 9th power (EC and granular cornmeal bait formulations) or 10 to the 8th power (residue formulation) fungal spores per square meter. In the second trial, two successive weekly treatments were applied, using a total of 6X the rate of application used in the first trial. The manure in the houses had accumulated for 5-6 months at the time of testing. Significant treatment effects were short-lived and only detected 2 weeks after treatment in both trials. The granular formulations of both strains and the residue formulation of the GHA strain provided the greatest degree of suppression (60-90 percent) of beetle larvae. A laboratory bioassay confirmed that the granular bait was the most effective formulation. More frequent applications made earlier in the manure accumulation cycle may be necessary to achieve satisfactory control of these beetles.