Protein self‐marking by emerald ash borer: an evaluation of efficacy and persistence

Scott W Gula,Matthew D Ginzel,Vanessa M Lopez,Ann M Ray,Scott A Machtley,James R Hagler

doi:10.1111/eea.12941

Abstract

AbstractUnderstanding the dispersal ability of invasive insects provides useful insights for developing effective management strategies. Historically, methods for marking insects for dispersal studies have been expensive, time‐consuming, labor‐intensive, and oftentimes ineffective, especially for woodboring beetles. Also, capturing or rearing insects requires human handling, which can alter behavior. Protein immunomarking is a well‐established technique for studying the dispersal of insects; however, it has not been applied to woodborers. This study evaluates the potential for using protein immunomarkers applied directly to woodborer‐infested trees to mark emerging beetles. Specifically, in the first experiment, we sprayed varying concentrations of ovalbumin (egg white) solution directly onto logs infested with emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae, Agrilini). In turn, an enzyme‐linked immunosorbent assay was used to detect the presence of protein on emerged beetles. To test the persistence of the mark, we applied varying concentrations of albumin to freeze‐killed beetles, mounted them on pins, and placed them over various time intervals in an exposed location outdoors. Adult EAB self‐marked as they emerged from protein‐treated trees, with higher protein concentrations persisting for longer on the cuticle. This technique offers a convenient, inexpensive, and durable means of marking woodborers and circumvents the need for human handling, allowing for more natural behavior and more realistic estimates of dispersal. Protein self‐marking may find application in studies of woodborer dispersal within natural forest environments.

Highlights

Woodboring beetles, especially invasive species, are among the most important pests to threaten the health and productivity of forests worldwide (Muirhead et al, 2006; Holmes et al, 2009; Haack et al, 2010; Kovacs et al, 2010, Bradshaw et al 2016)
Agrilus planipennis (Coleoptera: Buprestidae), self-marked as they emerged from protein-treated trees, and higher protein concentrations persisted longer on the cuticle when exposed to sun and rain
Our study demonstrates that woodboring beetles can acquire ovalbumin as they emerge from protein-treated host material, suggesting that immunomarking can be an effective tool for field-marking woodborers for dispersal research

Summary

Introduction

Woodboring beetles, especially invasive species, are among the most important pests to threaten the health and productivity of forests worldwide (Muirhead et al, 2006; Holmes et al, 2009; Haack et al, 2010; Kovacs et al, 2010, Bradshaw et al 2016). Mark-capture is an alternative approach for investigating within-stand dispersal and involves directly marking individuals of a naturally occurring insect population in the field, measuring their dispersal from the point of marking to the point where they are captured (Hagler & Jackson, 2001) This approach requires marking large numbers of insects, it has advantages over mark-release-recapture techniques because it circumvents the effort involved in capturing or rearing them. Protein marking techniques can be especially useful for understanding woodborer dispersal within natural areas because they are inexpensive, readily available, relatively safe for humans, nontoxic to insects, do not require special permits for use, and direct application to a substrate in the field eliminates the need for mass acquisition of study individuals, typically a major obstacle to research on many woodborers (Hagler & Jackson, 2001; Slosky et al, 2012; Hagler, 2019). The information gained from this study can be applied to provide a realistic assessment of woodborer dispersal in order to inform management efforts and reduce their negative impacts on forest ecosystems

Materials and methods

Results

Findings

Discussion