Binomial sequential sampling plan for hemlock woolly adelgid (Hemiptera: Adelgidae) sistens infesting individual...

Area of Science:

• Entomology
• Forestry
• Ecology

Background:

• The hemlock woolly adelgid (Adelges tsugae) is an invasive insect devastating eastern hemlock (Tsuga canadensis) and Carolina hemlock (Tsuga caroliniana) populations in the eastern U.S.
• Accurate and efficient monitoring is crucial for managing this significant forest pest.

Purpose of the Study:

• To develop a binomial sequential sampling plan for Adelges tsugae sistens.
• To create a cost-effective and efficient tool for assessing hemlock woolly adelgid infestations on individual eastern hemlock trees.

Main Methods:

• Utilized the sequential interval procedure for developing the sampling plan.
• Employed nondestructive sampling of new shoots on eastern hemlock trees.
• Established binomial classification based on infestation thresholds of 10% and 30% of new shoots.

Main Results:

• The developed plan achieved actual type I (alpha) and type II (beta) error rates of approximately 5% and 10%, respectively.
• Classifying infestation levels (low, high, or indeterminate) required examining 20–80 new shoots per tree.
• The sampling process was rapid, taking less than 2 minutes per tree.

Conclusions:

• The binomial sequential sampling plan provides an efficient and cost-effective method for managing hemlock woolly adelgid infestations.
• This tool can aid land managers in making timely decisions for protecting high-value eastern hemlock trees.
• The plan's speed and accuracy support proactive pest management in eastern forests.