Suppression of mosquito (Diptera: Culicidae) and black fly (Diptera: Simuliidae) blood feeding from Hereford cattle and ponies treated with permethrin.

The research article explores the impact of permethrin treatment on the blood feeding tendencies of mosquitoes and black flies from Hereford cattle and ponies. It suggests that permethrin significantly reduces the blood feeding activity of these insects, therefore potentially lessening the exposure of the livestock to insect-transmitted diseases.

Experiment Methodology and Results

• The researchers used an animal enclosure trap sample system to evaluate the effect of permethrin on the blood feeding behavior of Aedes dorsalis Meigen, A. melanimon Dyar, Simulium bivittatum Malloch, and S. griseum Coquillett.
• Hereford cattle were treated with commercial formulations of permethrin through pour-on concentrate and whole body spray treatments. In contrast, the ponies were treated with a permethrin fly wipe.
• Four days after treatment, a significant reduction of 79 to 88% was observed in the blood feeding of Aedes mosquitoes from the treated heifers. Similarly, blood feeding was reduced by 96 to 99% for the Simulium black flies. At 11 days post-treatment, the reductions in blood feeding were lower and not significant, ranging from 30 to 87%.
• For the ponies, significant reductions of 98% and 87% were observed in the blood feeding of S. bivittatum at 1 and 7 days post-treatment respectively.

Potential Benefits of Permethrin Treatment

• The study didn’t observe any treatment-induced mortality in the recently blood-fed female mosquitoes or black flies captured from the treated animals after being held for 24 hours.
• The researchers built a model to analyze the potential of using permethrin to save livestock from insect-transmitted diseases. They predicted that a 90% reduction in blood feeding could prevent the host’s exposure to the pathogen for up to 10 or 100 days, with varying rates of insect feeding and infection.

Conclusions

• The study suggests that using permethrin to treat livestock could substantially reduce insect blood feeding thereby lowering the exposure to insect-transmitted diseases.
• Whilst the permethrin showed a significant initial effect on the exposure rates, the reduction in blood feeding decreased over time.
• Further research could shed more light on the long-term effectiveness of permethrin treatments, as well as potential side effects on both the animals and insects.