Effects of antibacterial materials on Bemisia argentifolii (Homoptera: Aleyrodidae) oviposition, growth, survival, and sex ratio

Whiteflies and other homopterous insects contain endosymbiotic organisms that are essential for their development and reproduction. Reduction or elimination of the endosymbiotic organisms in insects by antibiotic therapy results in reduced insect growth, death, or lack of reproduction. Thus, endosymbionts provide a potential target for insect control with systemic antibacterial materials, or transgenic plants that produce antibacterial proteins. We investigated the effects of various antibiotics, with different ranges of activity and modes of action, on the whitefly Bemisia argentifolii Bellows & Perring (also known as Bemisia tabaci B biotype) oviposition rate, growth, survival, emergence as adults, and sex ratio. The materials tested were oxytetracycline hydrochloride, rifampicin, penicillin, ampicillin, lysozyme, and chloramphenicol. Method of application (feeding on diet or excised leaves) showed similar effects on adults or nymphs. Of the materials tested, those that had significant negative effects on growth and development of whiteflies (tetracycline and rifampicin) interfere with bacterial protein synthesis. Those materials that primarily attack the bacterial cell walls or cell membranes (penicillin, ampicillin, and lysozyme) did not have any significant effect on growth and development. Treatments with antibacterial materials had no significant effect on oviposition rates of adults or the sex ratio of their offspring. Delays in development, and reduction in the percentage of offspring emerging as adults provide ample evidence that antibacterial materials have potential role in management strategies against both adult and immature stages of whiteflies.