Cold hardiness in Spathius galinae (Hymenoptera: Braconidae), a larval parasitoid introduced for biocontrol of emerald ash borer in North America

AbstractEmerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an Asian species that was introduced into North America in the mid-1990s. The beetle has the potential to devastate populations of Fraxinus Linnaeus (Oleaceae) species. Several species of Hymenoptera parasitoids have made the transition from North American Agrilus Curtis hosts to A. planipennis, and some (e.g., Atanycolus Förster (Hymenoptera: Braconidae) species) have caused substantial mortality. Invertebrate predators of A. planipennis have been poorly investigated. Predation by woodpeckers (Aves: Picidae) has had the greatest impact on A. planipennis populations. Native entomopathogens have also been observed in populations of A. planipennis and are being explored as potential biological control agents. Agrilus planipennis is a freeze-intolerant species and as such perishes when its tissues freeze. However, the beetle can achieve a mean supercooling point of −30 °C by the production of cryoprotectants, especially glycerol. This low supercooling point in combination with temperatures higher than ambient in its overwintering microhabitat means that it can survive in most of its invaded range. As its distribution expands northward its cold hardiness may be challenged. North American species of Fraxinus possess some resistance to A. planipennis via defensive mechanisms, but these are quickly overcome by expanding larval populations. Intraspecific competition (via cannibalism and starvation) impacts larval survival.

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Establishment and Early Impact of Spathius galinae (Hymenoptera: Braconidae) on Emerald Ash Borer (Coleoptera: Buprestidae) in the Northeastern United States

Journal of Economic Entomology ◽

10.1093/jee/toz159 ◽

2019 ◽

Vol 112 (5) ◽

pp. 2121-2130 ◽

Cited By ~ 10

Author(s):

Jian J Duan ◽

Roy G Van Driesche ◽

Ryan S Crandall ◽

Jonathan M Schmude ◽

Claire E Rutledge ◽

...

Keyword(s):

New York ◽

North America ◽

Emerald Ash Borer ◽

Management Plan ◽

Agrilus Planipennis ◽

Natural Forests ◽

Natural Ecosystems ◽

Marginal Rate ◽

Larval Parasitoid ◽

Ash Trees

Abstract The emerald ash borer (EAB), Agrilus planipennis Fairmaire, a buprestid beetle native to Asia, has become a serious pest of ash trees (Fraxinus spp.) in North America since the early 2000s. Due to the impracticality of applying insecticides in natural forests, biocontrol is the most viable method to manage EAB in natural ecosystems. Here, we report the first evidence for the establishment and impact of Spathius galinae Belokobylskij & Strazenac, a larval parasitoid first released in North America in 2016 and 2017 at six mixed-hardwood forest sites, in Connecticut, New York, and Massachusetts. We also report current levels of abundance and parasitism of another introduced larval EAB parasitoid, Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae), released in 2015 and 2016 in these same sites. Spathius galinae was recovered at all release sites in 2018, and its density in sampled trees had increased 1.5- to 20-fold (relative to the first postrelease sample year), reaching a final density of 2.3–14.3 broods/m2 of phloem area and causing 13.1–49.2% marginal rate of parasitism at four of the six sites. In contrast, T. planipennisi was only recovered in 2018 at four of the six release sites, and both its density (0.1–2.3 broods/m2 of phloem area) and parasitism (0.1–5.6%) were lower than that of S. galinae throughout the study at the four sites where recoveries were made. Our data fill a critical gap in the development of a biocontrol-based EAB management plan to protect surviving ash trees capable of reaching maturity and producing replacement trees.

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Biology and Life History ofAtanycolus cappaerti(Hymenoptera: Braconidae), a North American Larval Parasitoid Attacking the Invasive Emerald Ash Borer (Coleoptera: Buprestidae)

Florida Entomologist ◽

10.1653/024.099.0423 ◽

2016 ◽

Vol 99 (4) ◽

pp. 722-728 ◽

Cited By ~ 3

Author(s):

Jian J. Duan ◽

Jonathan Schmude

Keyword(s):

Life History ◽

North American ◽

Emerald Ash Borer ◽

Larval Parasitoid

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Evaluation of the host specificity of Spathius galinae (Hymenoptera: Braconidae), a larval parasitoid of the emerald ash borer (Coleoptera: Buprestidae) in Northeast Asia

Biological Control ◽

10.1016/j.biocontrol.2015.06.005 ◽

2015 ◽

Vol 89 ◽

pp. 91-97 ◽

Cited By ~ 10

Author(s):

Jian J. Duan ◽

Juli R. Gould ◽

Roger W. Fuester

Keyword(s):

Host Specificity ◽

Northeast Asia ◽

Emerald Ash Borer ◽

Larval Parasitoid

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Emerald Ash Borer in North America: A Research and Regulatory Challenge

American Entomologist ◽

10.1093/ae/51.3.152 ◽

2005 ◽

Vol 51 (3) ◽

pp. 152-165 ◽

Cited By ~ 310

Author(s):

David Cappaert ◽

Deborah G. McCullough ◽

Therese M. Poland ◽

Nathan W. Siegert

Keyword(s):

North America ◽

Emerald Ash Borer ◽

Regulatory Challenge

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Natural enemies of emerald ash borer (Coleoptera: Buprestidae) in northeast China, with notes on two species of parasitic Coleoptera

The Canadian Entomologist ◽

10.4039/tce.2015.57 ◽

2015 ◽

Vol 148 (3) ◽

pp. 329-342 ◽

Cited By ~ 11

Author(s):

Xiao-Yi Wang ◽

Liang-Ming Cao ◽

Zhong-Qi Yang ◽

Jian J. Duan ◽

Juli R. Gould ◽

...

Keyword(s):

Natural Enemies ◽

Geographic Origin ◽

Emerald Ash Borer ◽

Egg Parasitoid ◽

Agrilus Planipennis ◽

Liaoning Province ◽

Natural Forests ◽

Mortality Factors ◽

Larval Parasitoid ◽

Time Of Year

AbstractTo investigate natural enemies of emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), in northeastern China, we conducted field surveys of ash (Fraxinus Linnaeus (Oleaceae)) trees in semi-natural forests and plantations at variable EAB densities from 2008 to 2013. Our surveys revealed a complex of natural enemies including eight hymenopteran parasitoids and two apparently parasitic Coleoptera, woodpeckers, and several undetermined mortality factors. Parasitoid complex abundance and its contribution to EAB mortality varied with the time of year, type of ash stands, and geographic regions. The egg parasitoid Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae) and the larval parasitoid Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) were frequently observed in Jilin, Liaoning, and Heilongjiang provinces and in Beijing, but not in Tianjin. Spathius agrili Yang (Hymenoptera: Braconidae), however, was more prevalent near Beijing and further south in Tianjin. Larvae of two species of apparently parasitic beetle, Tenerus Laporte (Coleoptera: Cleridae) species and Xenoglena quadrisignata Mannerheim (Coleoptera: Trogossitidae), were also recovered attacking overwintering EAB in Liaoning Province, with Tenerus species being a dominant mortality agent (~13%). Our findings support the need to consider the geographic origin of insect natural enemies for EAB biocontrol, as well as an expanded foreign exploration for EAB natural enemies throughout its native range in Asia.

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Challenges, tactics and integrated management of emerald ash borer in North America

Forestry An International Journal of Forest Research ◽

10.1093/forestry/cpz049 ◽

2019 ◽

Cited By ~ 3

Author(s):

Deborah G McCullough

Keyword(s):

North America ◽

Integrated Management ◽

Management Strategies ◽

Emerald Ash Borer ◽

Interspecific Variation ◽

Agrilus Planipennis ◽

Local Conditions ◽

Ash Trees ◽

Invasion Impacts ◽

Individual Trees

Abstract Emerald ash borer (EAB) (Agrilus planipennis Fairmaire), discovered in southeastern Michigan, USA in 2002, has become the most destructive and costly invasive forest insect in North America. This phloem-boring beetle has also invaded Moscow, Russia and continued spread of EAB potentially threatens European ash (Fraxinus spp.) species. This review summarizes EAB life history, including interspecific variation in host preference, invasion impacts and challenges of detecting new infestations and provides an overview of available management tactics. Advances in systemic insecticides, particularly emamectin benzoate products applied via trunk injection, have yielded effective and practical options both to protect individual trees and to slow EAB population growth and ash decline on an area-wide basis without disrupting natural enemies. Economic costs of treating ash are substantially lower than removal costs, retain ecosystem services provided by the trees, reduce sociocultural impacts and conserve genetic diversity in areas invaded by EAB. Girdled ash trees are highly attractive to EAB adults in low-density populations and debarking small girdled trees to locate larval galleries is the most effective EAB detection method. An array of woodpeckers, native larval parasitoids and introduced parasitoids attack EAB life stages but mortality is highly variable. Area-wide management strategies that integrate insecticide-treated trees, girdled ash trap trees and biological control can be adapted for local conditions to slow and reduce EAB impacts.

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Estimates of emerald ash borer (Coleoptera: Buprestidae) larval galleries in branch samples from asymptomatic urban ash trees (Oleaceae)

The Canadian Entomologist ◽

10.4039/tce.2015.68 ◽

2015 ◽

Vol 148 (3) ◽

pp. 361-370 ◽

Cited By ~ 7

Author(s):

Jean J. Turgeon ◽

Jeffrey G. Fidgen ◽

Krista L. Ryall ◽

Taylor A. Scarr

Keyword(s):

Cost Effectiveness ◽

North America ◽

Surface Area ◽

Predictive Power ◽

Emerald Ash Borer ◽

Cost Effective ◽

Agrilus Planipennis ◽

Significant Source ◽

Resource Managers ◽

Ash Trees

AbstractAgrilus planipennis (Coleoptera: Buprestidae), is causing extensive mortality of ash (Fraxinus Linnaeus; Oleaceae) in North America. Once detected in an area, resource managers require methods to obtain estimates that could improve management decisions. We studied the within-crown and within-branch distribution and abundance of A. planipennis feeding galleries by sampling 3-m-long branches from asymptomatic urban ash trees and subdividing each branch into 12 sections of 25 cm each. We found galleries in all 12 sections of some, but not all, branches. Section was a significant source of variation in A. planipennis gallery density/m2 of branch surface area. A comparison of predictive power and efficiency of estimates for samples of increasing length, and for samples of the same length but consisting of different combinations of sections, revealed that those based on the two basal 25-cm sections of a branch from the lower-crown or mid-crown of an asymptomatic tree were less accurate and precise than those based on more sections, but were the most cost effective. Whittling more sections per branch, irrespective of the combinations of branch sections per length, improved predictive power but reduced cost effectiveness. We also observed that crown level was not important, and aspect was only marginally so, when estimating gallery abundance per sampled branch.

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