Effects of sodium tetraborate and imidacloprid on the reproductive physiology of Anastrepha suspensa (Loew) (Diptera: Tephritidae).

摘要

Since bait spray with malathion to control Anastrepha suspensa , an economically important insect pest in Florida, has resulted in environmental and public protests due to environmental and human health concerns, interest has been shifted to compounds with environmental and toxicological safety, including boron compounds. The effects of sodium tetraborate and imidacloprid on survival and reproduction of A. suspensa were evaluated in the laboratory; the possible action mechanism of sodium tetraborate on egg development of A. suspensa was investigated.; The fecundity and fertility of A. suspensa were significantly reduced when flies were treated with 0.5% sodium tetraborate by feeding for 24 hr or 48 hr regardless of fly age. If treatment was continued over 168 hr, the effective concentration was reduced to 0.1%; higher concentrations killed most flies and terminated oviposition of survivors for 20 d after treatment. Sodium tetraborate (≤1.0%) was not repellent to A. suspensa.; Proteinase activities in the midgut of female A. suspensa were reduced for 4–5 d after treatment with 0.5% sodium tetraborate by feeding for 24 hr. Proteinase activities in the ovary of 7-d-old A. suspensa treated as a newly emerged adult were significantly reduced by 0.5% sodium tetraborate. General esterase activity levels were also affected in the abdomen of A. suspensa after treatment with 0.5% sodium tetraborate; esterase activities were increased in the female abdomen and decreased in the male abdomen.; Morphological examination showed that ovarian development of A. suspensa was inhibited when flies were treated with 0.5% sodium tetraborate for 24 hr and the inhibition resulted from reduction of yolk protein accumulation in oocytes. Vitellogenin gene transcription in the ovary of treated flies was delayed, and vitellogenin synthesis was subsequently reduced.