A bioassay was conducted to determine the impact of methoprene, an insect growth regulator (IGR), on fecundity, larval survival, and size of progeny for Onthophagus taurus Schreber. Adult O. taurus dung beetles were offered methoprene-treated manure in three to five replications each at concentrations of 0.08, 0.45, and 4.5 ppm, respectively. An additional group of adult beetles was immersed in a methoprene-water solution and allowed to reproduce in containers with untreated manure. Data from all treatment groups were compared with untreated control groups. Methoprene did not seem to hinder brood production at 0.45 ppm. Survival of O. taurus was not affected by methoprene-treated manure at 0.08 ppm or when parent beetles were immersed in methoprene-water solution. However, progeny survival was significantly reduced on manure treated with methoprene at 4.5 ppm. Mean pronotal width of O. taurus progeny was significantly smaller in beetles fed methoprene-treated manure (4.5 ppm). The low dose of 0.08 ppm did not affect pronotal widths nor did topical application of methoprene to adults affect pronotal widths in resulting offspring. Although some adverse effects of methoprene were observed at higher concentrations, use of methoprene at concentrations of 0.08 ppm as part of a horn fly control program likely would not greatly affect populations of O. taurus, the most common paracoprid dung beetle in North Carolina.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.