Effects of diet-age and streptomycin on virulence of Autographa californica M nucleopolyhedrovirus against the tobacco budworm

Kelli Hoover, Christine M. Schultz, Stephen S. Lane, Bryony C. Bonning, Bruce D. Hammock, Sean S. Duffey

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

Addition of the antibiotic streptomycin to two artificial diets routinely used in bioassays of neonate larvae of Heliothis virescens (tobacco budworm) infected with Autographa californica M nucleopolyhedrovirus (AcMNPV) increased lethal times of the virus. After storage of diets for 3 weeks at 4°C, lethal times of infected larvae were significantly slower compared to those for larvae bioassayed using diets stored for 2 weeks or less. The effect of diet-age on rate of mortality was not the result of a change in total protein content or pH of the diet, but was apparently the result of some other alteration in the quality of the diet (e.g. microbial spoilage, palatibility, and/or nutritional value unrelated to total protein). Although we did not determine why lethal times were slower in response to streptomycin concentration or diet-age, we did find that slower lethal times were correlated with slower relative growth rates (RGR) of infected larvae. In addition, RGR of infected larvae decreased as a function of increasing streptomycin concentration, diet-age, and the interaction of the two factors. These results demonstrate that it is difficult to obtain consistent and comparable bioassay results if antibiotic composition and diet-age are not controlled. We suggest a standardized diet or highly standardized procedures for a given diet be developed that permits comparison of bioassays among and within laboratories.

Original languageEnglish (US)
Pages (from-to)46-50
Number of pages5
JournalJournal of invertebrate pathology
Volume69
Issue number1
DOIs
StatePublished - Jan 1997

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All Science Journal Classification (ASJC) codes

  • Ecology, Evolution, Behavior and Systematics

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