Risk Assessment of Two Insecticides on

Area of Science:

• Agricultural Entomology
• Ecotoxicology
• Integrated Pest Management (IPM)

Background:

• Effective insecticide selection is vital for integrated pest management (IPM) success.
• Assessing acute toxicity to natural enemies like Encarsia formosa is crucial for sustainable pest control.
• Bemisia tabaci is a significant agricultural pest, and E. formosa is a key natural enemy.

Purpose of the Study:

• To evaluate the acute toxicity of abamectin and imidacloprid against the parasitoid Encarsia formosa.
• To investigate the sublethal effects of these insecticides on the searching behavior of E. formosa.

Main Methods:

• Laboratory assessment of acute toxicity of abamectin and imidacloprid on E. formosa.
• Quantification of dwelling time and entering frequency of E. formosa in infested and non-infested plant areas under varying insecticide concentrations (LC1, LC10, LC30).

Main Results:

• Abamectin exhibited high acute toxicity to E. formosa, while imidacloprid showed medium toxicity.
• Both insecticides significantly reduced E. formosa's dwelling time and entering frequency within infested plant areas.
• Sublethal concentrations (LC10, LC30) of abamectin and imidacloprid negatively affected E. formosa's host-searching behavior.

Conclusions:

• Abamectin and imidacloprid present considerable risks to E. formosa, impacting its efficacy as a biological control agent.
• The sublethal effects on searching behavior are critical considerations for insecticide use in IPM programs.
• Careful selection of insecticides is necessary to conserve natural enemies and maintain effective pest control.