%0 Journal Article
%T Composition, Repellent, and Insecticidal Activities of Two South American Plants against the Stored Grain Pests Tribolium castaneum and Tribolium confusum (Coleoptera: Tenebrionidae)
%A Ver¨®nica Benzi
%A Natalia Stefanazzi
%A Ana Paula Murray
%A Jorge O. Werdin Gonz¨¢lez
%A Adriana Ferrero
%J ISRN Entomology
%D 2014
%R 10.1155/2014/175827
%X As part of a screening program to evaluate the biological activity of indigenous plants, we report the composition and the bioactivity of essential oils (EOs) extracted from T¨¦ de Burro Aloysia polystachya [(Griseb.) Moldenke] and Lemon Verbena Aloysia citriodora [Palau] against two of the most widespread secondary pests of stored products, the red flour beetle Tribolium castaneum [Herbst] and the confused flour beetle Tribolium confusum [Jacqueline du Val]. Analysis by gas chromatography-mass spectrometry of the EOs led the identification of their major constituents and their relative proportions. EO of A. citriodora showed the highest repellent activity against both beetles (>70%). On the other hand, both plants showed fumigant toxicity only against T. confusum, without significant differences between them (LC50 values of 5.92 and 5.53£¿mg/L air for A. polystachya and A. citriodora, resp.). For contact toxicity (topical applications) the EO of A. polystachya was more effective (LD50 = 7.35£¿¦Ìg/insect) than the EO of A. citriodora (LD50 = 13.8£¿¦Ìg/insect) only against T. castaneum. On the other hand, T. confusum was not susceptible by contact to any of these EOs. These results provide important tools for the development of an Integrated Pest Management (IPM) program. 1. Introduction The red flour beetle Tribolium castaneum (Herbst) and the confused flour beetle Tribolium confusum (Duval) (Coleoptera: Tenebrionidae) are the most widespread and destructive secondary pests of stored grains and grain-derived products. They have been reported as serious pests in Argentina. Particularly, T. castaneum has been found as one of the most prevalent secondary pests in port areas of Buenos Aires province [1]. Control of these insects is primarily dependent upon continuous application of synthetic insecticides, which produce disturbance in the environment, increasing costs of application, pest resurgence, pest resistance, and lethal effects on nontarget organisms, in addition to direct toxicity to users. Thus, the risks associated to the use of these products have led to the growth of environmentally sustainable alternatives. In the last couple of decades, agrochemical companies have promoted the study of natural products for the development of new insecticides. An evidence of that is the number of organic agriculture products that reached the market [2, 3]. Thus, insecticides of natural origin are proposed as rational alternatives to synthetic ones and, among the biopesticides, essential oils (EOs) are growing rapidly on the botanical pesticide markets [4]. The
%U http://www.hindawi.com/journals/isrn.entomology/2014/175827/