Fixed precision sampling plans for white apple leafhopper (Homoptera: Cicadellidae) on apple

Area of Science:

• Agricultural Entomology
• Ecosystem Stability Monitoring

Background:

• Integrated Pest Management (IPM) programs are shifting away from broad-spectrum pesticides.
• There is a need for reliable indicator species to monitor agroecosystem stability under new IPM strategies.
• The white apple leafhopper (Typhlocyba pomaria McAtee) is a potential candidate for such an indicator species.

Purpose of the Study:

• To develop constant precision sampling plans for Typhlocyba pomaria McAtee.
• To enable the use of T. pomaria as an indicator species for agroecosystem stability.
• To support the implementation of new IPM programs in apple orchards.

Main Methods:

• Taylor's power law was employed to establish the relationship between mean and variance of T. pomaria populations.
• Green's constant precision sequential sample equation was utilized to formulate the sampling plans.
• Bootstrap simulations were conducted to assess the precision and efficiency of the developed sampling plans.

Main Results:

• The developed sampling plans demonstrated higher precision (D = 0.25) than the initially desired precision (Do = 0.3), especially at lower population densities.
• Adjusting Green's equation parameter (Do) to 0.4 resulted in a 25% reduction in the average sample number while maintaining adequate precision (average D = 0.31).

Conclusions:

• The developed constant precision sampling plans are effective for monitoring Typhlocyba pomaria.
• T. pomaria can serve as a reliable indicator species for assessing agroecosystem stability in Washington apple orchards.
• These plans facilitate the transition to IPM strategies that minimize reliance on broad-spectrum pesticides.