Low-Cost-High-Efficacy Control of Faba Bean Aphids by Fungal and Chemical Insecticides Co-Applied at Low and...

Area of Science:

• Agricultural Entomology
• Biological Control
• Sustainable Pest Management

Background:

• High costs of mycoinsecticides limit their use in green agriculture.
• Faba bean aphids (Aphis fabae) pose a significant threat to crop yields.
• Exploring synergistic interactions between fungal and chemical insecticides is crucial for cost-effective pest control.

Purpose of the Study:

• To evaluate the synergistic effects of Beauveria bassiana (Bb) and imidacloprid (ImD) against Aphis fabae.
• To determine if reduced rates of co-applied insecticides can maintain high efficacy while lowering costs.
• To assess the economic viability of fungal-chemical insecticide combinations for sustainable aphid management.

Main Methods:

• Two six-week field trials were conducted using 50-m² plots.
• Treatments included Beauveria bassiana (Bb) and imidacloprid (ImD) at recommended and reduced co-applied rates (2/3Bb, 1/2Bb, 1/3Bb + 1/5ImD).
• Aphid populations were monitored, and efficacy was calculated based on population suppression.

Main Results:

• Imidacloprid (ImD) initially showed higher aphid suppression than Bb or combined treatments at cooler temperatures.
• At warmer temperatures, Bb and combined Bb + ImD treatments demonstrated superior or comparable efficacy to ImD alone.
• Reduced co-application rates (e.g., 2/3Bb + 1/5ImD) achieved significant aphid control (66% efficacy), reducing mycoinsecticide costs by 32-65%.

Conclusions:

• Low-rate co-applications of fungal (Beauveria bassiana) and chemical (imidacloprid) insecticides present a cost-effective strategy for sustainable aphid control.
• This approach enhances the accessibility of mycoinsecticides for broader application in green agriculture.
• Synergistic interactions between fungal and chemical agents offer a promising 'low-cost-high-efficacy' solution for pest management.