Knockdown Effects of Pyrethroid and Neonicotinoid-Treated Nets on Rhodnius prolixus

Area of Science:

• Vector-borne disease control
• Entomology
• Toxicology

Background:

• Kissing bugs (Rhodnius prolixus) transmit Trypanosoma cruzi, a parasite causing Chagas disease.
• Military personnel and working dogs in endemic regions are at risk of infection.
• Insecticide-treated netting is a key tool for vector control.

Purpose of the Study:

• To compare the time-dependent knockdown efficacy of dinotefuran (neonicotinoid) and esfenvalerate (pyrethroid) on commercial netting against Rhodnius prolixus.
• To evaluate the speed of action for rapid-response vector control strategies.

Main Methods:

• Adult Rhodnius prolixus were exposed to treated net clippings in modified WHO cone bioassays.
• Exposure durations ranged from 3 to 15 minutes, with knockdown assessed at 1-hour post-exposure.
• Statistical analyses included ANOVA, log-logistic, and probit regression to determine time-to-knockdown metrics.

Main Results:

• Dinotefuran achieved ≥85% knockdown by 6 minutes, while esfenvalerate required approximately 12 minutes.
• Both insecticides reached 100% knockdown by 15 minutes.
• Dinotefuran demonstrated significantly faster knockdown (KT₅₀ ≈ 0.18 min) compared to esfenvalerate (KT₅₀ ≈ 1.9 min).

Conclusions:

• Dinotefuran-treated netting provides substantially faster knockdown of Rhodnius prolixus than esfenvalerate-treated netting.
• Neonicotinoid-treated netting is a viable rapid-acting barrier for military operations where brief insect contact is likely.
• Findings support dinotefuran netting for vector control in high-risk environments, especially if pyrethroid resistance is a concern.