Establishment and control of Tribolium castaneum (Herbst, 1797) (Coleoptera: Tenebrionidae) with inert dusts in stored canola

Abstract

Tribolium castaneum (Herbst, 1797) is know as one of main pests of stored canola seeds worldwide, however, the cases of infestation in Brazil are still not reported. Due to its potential pest status allied to the increasing production of canola in Brazil, this work aims to evaluate the establishment of T. castaneum in canola stored seeds, as well as the effects of diferent inert dusts to its control. For stablishment determination, three substrates were tested: wheat bran (control); whole wheat seeds; and whole canola seeds. The insects remained in the substrates for 14 days, when mortality was counted, and then for aditional seven days before get removed, for progeny assessment at 66 days after initial exposure. For the insecticide potential of inert dusts, four treatments were tested in canola seeds as substrate: diatomaceous earth; basaltic rock powder; vegetable charcoal powder; and untreated canola seeds as control treatment. The beetles were exposed to the treated substrate and cumulated mortality was counted each two days for 15 days. Lower adult mortality and higher progeny in canola seeds indicates that these substrate is a potential host for T. castaneum. Diatomaceous earth and vegetable charcoal powder reduced the survival of adult beetles in canola in more than 60% at the end of the evaluation period. The T. castaneum adults and its offspring develops well in stored canola seeds. Additionally, the use of inert dusts, mainly diatomaceous earth and vegetable charcoal powder presents promising results of control of the beetle in stored canola seeds.