Limited Scope Risk Assessment for Nontarget Ground-Dwelling Arthropods From Systemic Insecticide Applications to...

Area of Science:

• Forestry
• Entomology
• Environmental Science

Background:

• Nantucket pine tip moth (NPTM) is a significant pest of young loblolly pines, impacting growth.
• Systemic insecticides are increasingly used for NPTM management, raising concerns about nontarget effects.
• Assessing environmental risks to non-target organisms is crucial for sustainable forestry practices.

Purpose of the Study:

• To evaluate the potential nontarget effects of four systemic insecticides on ground-dwelling arthropods in loblolly pine stands.
• To specifically examine the impact on collembolan (springtail) populations and genera richness.
• To provide data for informed decision-making regarding insecticide use in young pine regeneration.

Main Methods:

• Four systemic insecticides (chlorantraniliprole, dinotefuran, fipronil, imidacloprid) were applied to loblolly pine seedlings across three sites.
• Ground-dwelling arthropods were collected using pitfall traps 7-9 months post-application.
• Trap catch data, focusing on overall arthropods and specifically collembolans, were analyzed across treatments and collection times.

Main Results:

• No significant differences were found in ground-dwelling arthropod or collembolan trap catch, or collembolan genera richness among the insecticide treatments and the control group.
• Arthropod and collembolan populations, as well as collembolan genera richness, varied significantly based on the time of year the samples were collected.
• These findings represent a mid-term assessment of insecticide risks in this specific ecosystem.

Conclusions:

• The tested systemic insecticides did not demonstrate significant adverse effects on ground-dwelling arthropods in young loblolly pine stands within the study's timeframe.
• Seasonal variations in arthropod communities are a notable factor, independent of insecticide application.
• This research is a foundational step in understanding the environmental implications of systemic insecticide use for NPTM management in pine regeneration settings.