Effect of temperature on an enzyme assay to detect fenitrothion resistance in Anopheles albimanus mosquitos.

A laboratory strain of Anopheles albimanus Wiedemann of known fenitrothion resistance was used in the field to compare the results of the WHO test for determining fenitrothion resistance in mosquitos with those of an enzyme microplate assay. The level of resistance obtained with the enzyme assay increased with the ambient temperature, and in order to compensate for this temperature effect, the incubation time was reduced. With the adjusted incubation times, the results for the microassay from 23 degrees C to 32 degrees C were the same as those found with the WHO test. The fenitrothion resistance of a field population of A. albimanus mosquitos determined between 27 degrees C and 31 degrees C using the adjusted enzyme microassay or the WHO test did not differ in a statistically significant way.