The fumigant toxicity of various essential oils and selected monoterpenoid components were tested against the adult German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae). Responses varied according to plant material, concentration, and exposure time. | Turk J Agric For 33 (2009) 211-217 © TÜBİTAK doi: Fumigant Toxicity of Plant Essential Oils and Selected Monoterpenoid Components against the Adult German Cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae) Hasan TUNAZ, Mehmet Kubilay ER, Ali Arda IŞIKBER Department of Plant Protection, Faculty of Agriculture, Kahramanmaraş Sütçü İmam University, Kahramanmaraş - TURKEY Received: Abstract: The fumigant toxicity of various essential oils and selected monoterpenoid components were tested against the adult German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae). Responses varied according to plant material, concentration, and exposure time. High insecticidal activity against adult B. germanica specimens was achieved with allyl isothiocyanate (component −1 of horseradish) and the essential oil of Allium sativum (L.) (Liliales: Liliaceae) at the concentration of and 5 μl l of air, respectively, while the essential oils of Thymus vulgaris (L.) (Lamiales: Lamiaceae), Oregano dubium (L.) (Lamiales: Lamiaceae), Allium cepa (L.) (Liliales: Liliaceae), and Rosemarinus officinalis (L.) (Lamiales: Lamiaceae), and the monoterpenoid components eugenol, carvacrol, and citronella at the concentration of 5 μl l−1 of air did not show any insecticidal activity. Allyl isothiocyanate at μl l−1 of air caused 100% mortality within 18 h, whereas over 95% mortality within 48 h was achieved with the essential oil of A. sativum at 5 μl l−1 of air. Allyl isothiocyanate was the most toxic compound, followed by A. sativum oil. Concentration- and time-mortality tests were conducted for these 2 chemicals. Estimated LC50 and LT50 values for allyl isothiocyanate were μl l−1 of air and h, respectively. The findings show that allyl isothiocyanate and A. sativum had high insecticidal activity, and that they have potential as fumigants for use against the German cockroach. The essential oils and monoterpenoid components .
