Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/3/2007
Publication Date: 1/31/2007
Citation: Streett, D. A., Ni, Xinzhi, and Lawrence, A. M. 2008. Effect of DNA Gyrase Inhibitors in the NI diet on Biological Fitness of the Western Tarnished Plant Bug (Heteroptera: Miridae). J. Entomol. Sci. 43: 86-94.
Interpretive Summary: The western tarnished plant bug is an important economic pest that has an economic impact on US cotton of over $100 million in control costs and yield loss. This pest can be reared on an artificial diet in the laboratory for the purpose of developing and evaluating novel control technologies. Several inhibitors were found to reduce diet spoilage and improve insect egg production. These findings will reduce spoilage of insect diet and improve egg production in the laboratory.
Technical Abstract: Addition of three DNA-gyrase inhibitors (i.e., novobiocin, nalidixic acid and oxolinic acid) individually to the NI diet was investigated to assess their effect on the biological fitness of Lygus hesperus Knight (Heteroptera: Miridae). Biological fitness of the insects was measured by the number, biomass, sex ratio, daily egg count per female, and the egg hatch rate. All measures of biological fitness were not significantly different among the controls and the three inhibitors, which demonstrated that the inhibitors can effectively replace present antibiotics for a less expensive diet. Among the three inhibitors, the females reared on the NI diet with novobiocin and oxolinic acid showed an increase in fecundity in comparison to the diet with nalidixic acid, but the types of inhibitors had no effect on egg hatch rate. Furthermore, the egg hatch rate during the first 12 days after oviposition produced the most viable eggs with the highest egg hatch rate observed between the 2nd and 9th days after oviposition commenced, which is comparable to the current egg collection period used for the L. hesperus colony. These inhibitors could be used to replace the antibiotics currently present in the NI diet and reduce the cost for diet preservation without sacrificing the quality of the insects in the mass rearing facility.