Aedes aegypti dispersion is the major reason for the increase in dengue transmission in South America. In Brazil, control of this mosquito strongly relies on the use of pyrethroids and organophosphates against adults and larvae, respectively. In consequence, many Ae. aegypti field populations are resistant to these compounds. Resistance has a significant adaptive value in the presence of insecticide treatment.

This note has reference to the correspondence: ‘Bt cotton: refuge in mixed bag’ by Muralimohan and Srinivasa. In fact, their article itself was in response to an earlier correspondence entitled ‘Bt resistance in Helicoverpa species: Indian policy needs urgent revision’ by Hanur, in which the author has advocated ‘refuge in mixed bag’. Since Muralimohan and Srinivasa have raised certain concerns and opined against the use of ‘mixed bag’, I have made an attempt to address their concerns, clarify certain doubts and
also explain the need for this approach.(Correspondence)

Differences between individual human houses can confound results of studies aimed at evaluating indoor vector control interventions such as insecticide treated nets (ITNs) and indoor residual insecticide spraying (IRS). Specially designed and standardised experimental huts have historically provided a solution to this challenge, with an added advantage that they can be fitted with special interception traps to sample entering or exiting mosquitoes.

Insects are the pre-eminent form of metazoan life on land, with as many as 1018 individuals alive at any one instant and over three-quarters of a million species described. Although it is estimated that there are as many as 14,000 species that are blood feeders, only three to 400 species regularly attract our attention. Some of these are of immense importance to us, as vector-borne diseases still form a huge burden on both the human population and our domesticated animals.

Populations of honey bees and other pollinators have declined worldwide in recent years. A variety of stressors have been implicated as potential causes, including agricultural pesticides. Neonicotinoid insecticides, which are widely used and highly toxic to honey bees, have been found in previous analyses of honey bee pollen and comb material. However, the routes of exposure have remained largely undefined. We used LC/MS-MS to analyze samples of honey bees, pollen stored in the hive and several potential exposure routes associated with plantings of neonicotinoid treated maize.

To disseminate Insecticide Resistance Management (IRM) strategies, 10 villages were adopted in Muktsar district of Punjab during 2008 and 2009. Two villages were kept as check (Non-IRM) for comparing the impact of IRM strategies on the major insect pests and natural enemies in Bt cotton arthropod fauna.