Acta Tropica 127 (2013) 181–186 Contents lists available at SciVerse ScienceDirect Acta Tropica journal h om epa ge: www.elsevier.com/locate/actatropica Insecticidal and repellence activity of the essential oil of Pogostemon cablin against urban ants species Elânia L.D. Albuquerque, Janaína K.A. Lima, Felipe H.O. Souza, Indira M.A. Silva, Abraão A. Santos, Ana Paula A. Araújo, Arie F. Blank, Rafaely N. Lima, Péricles B. Alves, Leandro Bacci ∗ Universidade Federal de Sergipe, Cidade Universitária Professor José Aloísio de Campos, Avenida Marechal Rondon s/n, Rosa Elze, 49100-000, São Cristóvão, Sergipe, Brazil a r t i c l e i n f o Article history: Received 16 November 2012 Received in revised form 9 April 2013 Accepted 17 April 2013 Available online 30 April 2013 Keywords: Pest Patchouli Dorymyrmex thoracicus Camponotus melanoticus Camponotus novogranadensis a b s t r a c t Ants are highly abundant in neotropical regions, with certain species adapted to the urban environment, where they can cause damage to human health. The main method for controlling ants consists of using organosynthetic insecticides, which are potentially toxic to the environment. Essential plant oils are considered a viable alternative to the use of conventional insecticides. In this study, we analyze the bioinsecticidal activity and repellence of patchouli essential oil (Pogostemon cablin) against three species of urban ants: Camponotus melanoticus, Camponotus novograndensis, and Dorymyrmex thoracicus. The chemical composition of the essential oil was analyzed by GC–MS and GC-FID. The major compounds were patchoulol (36.6%) followed by -bulnesene (13.95%), and -guaiene (11.96%). Toxicity and repellency bioassays were performed using the essential oil over the ants, and mortality evaluations were performed at 4, 24, and 48 h after performing the bioassays. Mortality percentage of the ants on 7 g/mg was on average 84%. The essential oil of P. cablin displayed toxicity against all three species of urban ants, with the lowest LD 50 being observed for D. thoracicus (2.02 g oil/mg insect) after 48 h of exposure compared to C. melanoticus (2.34 g oil/mg insect) and C. novogranadensis (2.95 g oil/mg insect). The essential oil of P. cablin was strongly repellent to the three species of ants in all concentrations tested (0.01% and 1% v/v). Considering the potential toxicity and repellency of the P. cablin essential oil to the urban ants, future studies could investigate the practical application of this oil to control of this insects. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Ants (Hymenoptera: Formicidae) display a high degree of dom- inance and diversity in tropical environments (Hölldobler and Wilson, 1990), with certain species being considered agricultural and urban pests (Bueno et al., 2008; Jaffe, 2004). Numerous ants’ species colonize and exploit environments altered by human activity, most notably the genera Camponotus and Dorymyrmex (Campos-Farinha et al., 2002). Camponotus ants normally nest in diverse environments (Campos-Farinha et al., 2002), and possess broad ecological adaptations with opportunis- tic habits and an elevated capacity for invasion (Fonseca et al., 2010). Dorymyrmex is highly diversified genus with distribution restricted to the neotropical regions of the Americas. Several species demonstrate a large degree of endemism with preferential nesting in dry or disturbed habitats (Cuezzo and Guerrero, 2012). ∗ Corresponding author. Tel.: +55 79 21056981; fax: +55 79 21056494. E-mail address: bacci.ufs@gmail.com (L. Bacci). These organisms reside in houses, commercial establishments, and hospitals with the ability to cause discomfort and structural dam- age and to be vectors for pathogenic organisms (Campos-Farinha et al., 2002; Fonseca et al., 2010). Among the pathogens carried by ants, the bacteria Escherichia coli and Enterobacter spp. are causative agents of severe intestinal disorders and are responsible for hospital infections (Pesquero et al., 2008). Although several forms of control have been employed against urban ants, they are often inefficient. The use of conventional methods, in addition to resulting in the contamination of the envi- ronment, may lead to fragmentation of the colonies, increasing the number of nests and consequently the population of these insects (Fonseca et al., 2010). Other factors that impede the control of urban ants are inappropriate management practices, such as the use of agricultural insecticides that are not specific to the pests in question (Oliveira and Campos-Farinha, 2005). In recent years, a series of studies have shown that plants are potential sources of insecticides (Dugassa et al., 2009; Nerio et al., 2010; Odalo et al., 2005), thereby representing future alternatives for new methods for control of insect pests. Of the products with 0001-706X/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.actatropica.2013.04.011