Criterion | Example |
---|---|
Timeline: resistance in mosquitoes to a particular insecticide pre-dates public health or personal use of that insecticide at that site | Mosquito populations from Khartoum express 60–80 % mortality when exposed to the carbamate beniocarb, but carbamates are not approved for public health use in Khartoum, and are the most commonly used class of pesticides for agriculture [28] |
Correlation in time: vector resistance levels rise and fall with the agricultural spraying schedule at a sampling site over time | Mosquitoes collected from cotton farms in Cameroon during the cotton spraying season showed a 1.6-fold increase in median knockdown time relative to mosquitoes collected from the same sites just prior to the spraying [18] |
Correlation in space: vector populations from agricultural sites are more resistant to insecticides than their counterparts at non-agricultural sites in the same region | In Mali, the frequency of the kdr resistance gene was highest in mosquitoes sampled from a cotton-growing site, compared to sites with just personal or public health insecticide use history [30] |
Correlation in quantity: vector resistance levels in a population increase with increasing quantity of agricultural insecticides in that region | Mosquito populations collected from two vegetable farms in Benin showed mortality to insecticides that varied inversely with concentrations of insecticides in the soil and water from these sites [25] |
Chemical correlation: the insecticides to which a mosquito population is resistant correspond to the insecticides used for agricultural purposes in that area | At a site in Cameroon where pyrethroids make up a higher proportion of pesticides used in agriculture, mosquitoes showed higher pyrethroid resistance compared to mosquitoes from another agricultural site with less reliance on pyrethroids [26] |