Cascading ecological effects caused by the establishment of the emerald ash borer Agrilus planipennis (Coleoptera: Buprestidae) in European Russia

Marina J Orlova-Bienkowskaja

doi:10.14411/eje.2015.102

Abstract

Emerald ash borer, Agrilus planipennis, is a destructive invasive forest pest in North America and European Russia. This pest species is rapidly spreading in European Russia and is likely to arrive in other countries soon. The aim is to analyze the ecological consequences of the establishment of this pest in European Russia and investigate (1) what other xylophagous beetles develop on trees affected by A. planipennis, (2) how common is the parasitoid of the emerald ash borer Spathius polonicus (Hymenoptera: Braconidae: Doryctinae) and what is the level of parasitism by this species, and (3) how susceptible is the native European ash species Fraxinus excelsior to A. planipennis. A survey of approximately 1000 Fraxinus pennsylvanica trees damaged by A. planipennis in 13 localities has shown that Hylesinus varius (Coleoptera: Curculionidae: Scolytinae), Tetrops starkii (Coleoptera: Cerambycidae) and Agrilus convexicollis (Coleoptera: Buprestidae) were common on these trees. Spathius polonicus is frequently recorded. About 50 percent of late instar larvae of A. planipennis sampled were parasitized by S. polonicus. Maps of the distributions of T. starkii, A. convexicollis and S. polonicus before and after the establishment of A. planipennis in European Russia were compiled. It is hypothesized that these species, which are native to the West Palaearctic, spread into central European Russia after A. planipennis became established there. Current observations confirm those of previous authors that native European ash Fraxinus excelsior is susceptible to A. planipennis, increasing the threat posed by this pest. The establishment of A. planipennis has resulted in a cascade of ecological effects, such as outbreaks of other xylophagous beetles in A. planipennis-infested trees. It is likely that the propagation of S. polonicus will reduce the incidence of outbreaks of A. planipennis.

Highlights

An invasion of a non-native species of insect can by a cascading sequence of ecological effects affect the structure of an ecosystem (Kenis et al, 2009)
The cascading ecological effects that resulted from the establishment of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), in European Russia is described in the present article
The aim of this study is to analyze the ecological consequences of the establishment of A. planipennis in central European Russia and to answer the following questions: (1) What other xylophagous beetles develop on ash infested with A. planipennis?; (2) how common is the emerald ash borer parasitoid, Spathius polonicus, and what percentage of the emerald ash borer larvae are parasitized by this parasitoid?; and (3) how susceptible is the native European ash, Fraxinus excelsior, to attack by A. planipennis?

Summary

Introduction

An invasion of a non-native species of insect can by a cascading sequence of ecological effects affect the structure of an ecosystem (Kenis et al, 2009). Agrilus planipennis is one of the most destructive forest pests in the world (Aukema et al, 2011) This beetle originates from East Asia: Northeastern China, Korea, Japan, Taiwan and Russian Far East (Jendek, 1994; Wei et al, 2007). It was inadvertently introduced into North America in the 1990s (Siegert et al, 2014) and has destroyed tens of millions of ash trees there (Aukema et al, 2011). More than 80% of the ash trees in Moscow have been destroyed by this pest and there are additional infestations in 11 regions in central European Russia (Orlova-Bienkowskaja, 2013, 2014a, b; Baranchikov, 2013; Straw et al, 2013), but our understanding of the ecological effect of A. planipennis outbreak is limited

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