Dengue fever (DF) and dengue haemorrhagic fever are vector-borne diseases of public health importance in tropical, subtropical and temperate regions of the world

Dengue fever (DF) and dengue haemorrhagic fever are vector-borne diseases of public health importance in tropical, subtropical and temperate regions of the world (Gubler 1998). It is a popular belief that Aedes aegypti (Linnaeus) is the sole vector of the four distinct serotypes of dengue virus that causes the spectrum of disease symptoms collectively known as “dengue” (including DF, dengue haemorrhagic fever and dengue shock syndrome). However, other Aedes species, such as Aedes albopictus (Skuse), have been incriminated as DF vectors in epidemics in Southeast Asia and other parts of the world (Knudsen 1995) and could be responsible for the occurrence of these viruses in places where Ae. aegypti is absent (Shroyer 1986). Ae. albopictus is also a potential vector of several additional arboviruses, some of which have considerable medical importance, such as Chikungunya virus (Mangiafico 1971). Ae. aegypti and Ae. albopictus are able to coexist in man-made containers in urban, suburban and rural areas (Vezzani & Carbajo 2008). Additionally, Ae. albopictus larvae inhabit natural containers such as bromeliads, bamboo stumps and tree-holes close to human habitats and can survive throughout a broad range of temperatures and relative humidity (RH) levels (Hawley 1988). In North America, Ae. albopictus was first discovered in Texas (USA) in 1985 (Francy et al. 1990). In South America, it was discovered for the first time in Brazil during 1986 (Rai 1991). In Argentina, it was initially detected in Misiones near the Brazilian border, in early 1998 (Rossi et al. 1999, Schweigmann et al. 2004). The continuous expansion of the geographic range of Ae. albopictus in Latin America, including Argentina, the recent findings regarding its vector potential (Mitchell et al. 1987) and the observations made indicating a competitive advantage for Ae. albopictus over Ae. aegypti (Braks et al. 2004), have increased the public awareness of this mosquito and the attempts to control it. In the absence of a dengue vaccine, controlling dengue vectors is regarded as essential in preventing epidemics. The application of larvicides to containers that cannot be eliminated is still considered a priority by control programmes. However, this activity is both labour intensive and time consuming and not all containers can be treated because there are certain locations in and around urban areas that offer permanent breeding sites. In addition, the continuous application of insecticides in vector control strategies can result in the development of insecticide resistance. To contribute to the knowledge on the susceptibility of dengue vectors to insecticides, we determined a baseline susceptibility of laboratory strains of Ae. aegypti and Ae. albopictus larvae to the insecticides commonly used in Argentina for vector control. This information will be valuable in the implementation of further resistance monitoring programmes. According to our past Financial support: Agencia Nacional de Promoción Científica y Tecnológica (MINCyT Argentina) The research was conducted under a cooperative agreement with Chemotecnica SA (Argentina). + Corresponding author: [email protected] Received 31 March 2011 Accepted 31 August 2011 Comparison of the insecticide susceptibilities of laboratory strains of Aedes aegypti and Aedes albopictus