Contact and fumigant activity of 1,8-cineole, eugenol and camphor against <i>Tribolium castaneum</i> (Herbst)

Abstract

The red flour beetle, Tribolium castaneum (Herbst), holds a significant place in Croatia by causing considerably damages on stored products. This study was initiated in order to test contact and fumigant activity of three essential oil compounds (1,8-cineole, camphor and eugenol) for the control of adults of this stored-pest species. Contact toxicity of compounds was tested at four doses (0.2, 1.0, 5.0 and 10.0 μL/adult) and mortality was recorded every 2, 4 and 24 h after the application. The most effective compound was 1,8-cineole by its fastest action (2 h after application), with maximum mortality at the lowest dose (0.2 μL/adult). With its prolonged effect of 4 h, eugenol resulted in mortality of 87.5% at the dose of 0.2 μL/adult, while camphor obtained the highest mortality (78.5%) just after 24 h, and at the highest tested dose (10.0 μL/adult). Fumigant toxicity of compounds was tested at three doses (30, 60 and 120 μL/350 mL vol.) and after 48-h of exposure time; mortality was recorded every 24 h until the “end point mortality” (when no time-dependent changes in mortality occurred). The highest mortality (98.5%) had 1,8-cineole at the lowest dose (30 μL/350 mL vol.), followed by camphor (93.5%) at the highest dose (120 μL/350 mL vol.), while eugenol had no statistical significance in the control of T. castaneum adult by application of this fumigation method. Such investigations make positive contribution to new possible alternatives to conventional insecticides and fumigants used in protection of stored cereals.

Keywords: Tribolium castaneum, 1,8-cineole, Camphor, Eugenol, Contact and fumigant activity