Sampling Methods for Adventive Trissolcus japonicus (Hymenoptera: Scelionidae) in a Wild Tree Host of Halyomorpha...

Area of Science:

• Entomology
• Invasive Species Ecology
• Biological Control

Background:

• Halyomorpha halys (brown marmorated stink bug) is a significant invasive pest in the United States.
• Trissolcus japonicus, an Asian egg parasitoid of H. halys, is establishing and expanding its range in the US, including Virginia.
• Efficient methods for monitoring T. japonicus distribution and abundance are crucial research priorities.

Purpose of the Study:

• To compare the efficiency of sentinel H. halys egg masses and yellow sticky traps for detecting T. japonicus.
• To assess the optimal deployment strategy for yellow sticky traps in monitoring T. japonicus.
• To evaluate the time efficiency of different sampling methods for T. japonicus surveillance.

Main Methods:

• Sentinel H. halys egg masses were deployed in vertical transects in Ailanthus altissima canopies in Virginia (2016-2017).
• Yellow sticky traps were deployed in the same trees for comparison (2016-2017).
• Sampling methods were compared based on detection locations and estimated time inputs.

Main Results:

• Both sentinel eggs and yellow sticky traps detected T. japonicus primarily in the middle and upper tree canopies.
• Other H. halys parasitoids were found across all canopy levels (lower, middle, upper).
• Yellow sticky traps were found to be more time-efficient for T. japonicus surveillance than sentinel egg masses.

Conclusions:

• Yellow sticky traps are a more efficient sampling method for monitoring T. japonicus, particularly in the middle and upper canopy.
• This finding supports the use of yellow sticky traps for large-scale surveillance of T. japonicus range expansion and ecology.
• Optimized sampling methods are essential for effective management strategies against invasive pests like H. halys.