RESUMEN
Mosquito surveillance is critical for actively tracking the location and monitoring population levels and the threat of mosquito-borne disease. Although light-emitting diodes (LEDs) light traps have grown in popularity, there is still a limited understanding of the application of light wavelengths for trapping nocturnally active wild mosquitoes in forest ecotypes. This study evaluated the performance of different UV wavelengths in trapping mosquito populations in a forested mountainous area in Nakhon Ratchasima province, Thailand. Traps with different UV wavelengths were deployed in 6 locations, following a 6â ×â 6 Latin square replicated 6 times over a total of 36 nights. Light traps were operated between 18:00 and 06:00 h from October 2022 to August 2023. Mosquitoes were separately collected from individual traps every 4 h at 22.00, 2.00, and 6.00 h. Mosquitoes were killed by placing in a freezer (-â 20 °C) for at least 30 min and then were morphologically identified using illustrated keys for adult females. Traps fitted with the LED 365 wavelength light source were the most effective in capturing 790 (23.66%) of the total mosquitoes collected, followed by the UV fluorescent 632 (18.93%), with the other 4 LED wavelengths collecting between 16.89% (LED 385) and 12.64% (LED 375) of the mosquitoes. Culex was the most common genus, representing 56.00% of total mosquito abundance. LED 365 and LED 385 were comparable to the UV fluorescent traps (the standard reference). Optimal trapping times were during 18:00-22:00 h. Compared to the other wavelengths, LED 365 was significantly more effective at capturing Coquillettidia and Culex mosquitoes than the UV-based traps.
RESUMEN
Excito-repellency responses of Aedes aegypti (L.) exposed to deltamethrin and cypermethrin were assessed using an excito-repellency test system. Contact irritancy and non-contact repellency assays compared non-bloodfed (unfed) parous (post-gravid), nulliparous, early blood-fed, late blood-fed, sugar-fed, and unmated female mosquitoes for behavioral responses based on nutritional and physiological conditions at the time of testing. Rates of escape during contact exposure with either compound were most pronounced in parous mosquitoes, followed by unmated mosquitoes, when compared to other conditional states. Significantly higher numbers of parous females also escaped from control chambers compared to other cohorts (P <0.05). Irritability of blood- and sugar-fed mosquitoes was noticeably suppressed. We conclude that nutritional and physiological conditions (including age) of mosquitoes at the time of testing can significantly influence behavioral responses (excito-repellency) to insecticides. The findings indicate that whether due to chronological age, nutrition, physiological state, or innate (circadian) activity patterns, careful consideration must be given to the selection of appropriate conditioned mosquitoes for testing.