Primary screen for potential sheep scab control agents

Area of Science:

• Veterinary Entomology
• Parasitology
• Chemical Ecology

Background:

• Sheep scab, caused by the mite Psoroptes ovis, is a significant economic concern in sheep farming.
• Effective and safe control strategies for Psoroptes ovis infestations are crucial for animal welfare and productivity.

Purpose of the Study:

• To evaluate the in vitro efficacy of various chemical agents against the sheep scab mite, Psoroptes ovis.
• To identify potential new acaricidal agents for controlling sheep ectoparasites.

Main Methods:

• In vitro assays were conducted using modified test arenas to simulate off-host conditions for Psoroptes ovis.
• Forty-five different agents, including essential oils, desiccants, growth regulators, and neurotoxins, were tested.
• Mortality rates of adult and nymphal Psoroptes ovis were assessed for each agent.

Main Results:

• Desiccants (diatomaceous earth, nanoclay, sorex) demonstrated high efficacy.
• Growth regulators (buprofezin, hexythiazox, teflubenzuron) were effective against the mites.
• Lipid synthesis inhibitors (spirodiclofen, spirotetramat, spiromesifen) showed significant acaricidal activity.
• Nerve action and energy metabolism inhibitors (fenpyroximate, spinosad, tolfenpyrad, chlorantraniliprole) were also highly effective.

Conclusions:

• Several classes of chemical agents, including desiccants, growth regulators, lipid synthesis inhibitors, and nerve agents, show significant potential for controlling Psoroptes ovis.
• These findings provide a basis for further development of novel acaricides against sheep scab mites.