171 results on '"Herms, Daniel A"'
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152. Failure to Phytosanitize Ash Firewood Infested With Emerald Ash Borer in a Small Dry Kiln Using ISPM-15 Standards
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Charles Goebel, P., Bumgardner, Matthew S., Herms, Daniel A., and Sabula, Andrew
- Abstract
Although current USDA–APHIS standards suggest that a core temperature of 71.1°C (160°F) for 75 min is needed to adequately sanitize emerald ash borer, Agrilus planipennis Fairmaire-infested firewood, it is unclear whether more moderate (and economical) treatment regimes will adequately eradicate emerald ash borer larvae and prepupae from ash firewood. We constructed a small dry kiln in an effort to emulate the type of technology a small- to medium-sized firewood producer might use to examine whether treatments with lower temperature and time regimes successfully eliminate emerald ash borer from both spilt and roundwood firewood. Using white ash (Fraxinus americana L.) firewood collected from a stand with a heavy infestation of emerald ash borer in Delaware, OH, we treated the firewood using the following temperature and time regime: 46°C (114.8°F) for 30 min, 46°C (114.8°F) for 60 min, 56°C (132.8°F) for 30 min, and 56°C (132.8°F) for 60 min. Temperatures were recorded for the outer 2.54-cm (1-in.) of firewood. After treatment, all firewood was placed under mesh netting and emerald ash borer were allowed to develop and emerge under natural conditions. No treatments seemed to be successful at eliminating emerald ash borer larvae and perpupae as all treatments (including two nontreated controls) experienced some emerald ash borer emergence. However, the 56°C (132.8°F) treatments did result in considerably less emerald ash borer emergence than the 46°C (114.8°F) treatments. Further investigation is needed to determine whether longer exposure to the higher temperature (56°C) will successfully sanitize emerald ash borer-infested firewood.
- Published
- 2010
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153. Comparison of Two Methods for Sampling Arboreal Insect Populations
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Herms, Daniel A., Nielsen, David G., and Sydnor, Davis T.
- Abstract
Beating tray and D-vac sampling were compared and evaluated for their ability to estimate the phenology of insects on honeylocust (Gleditsia triacanthos L.). The insects were honeylocust plant bug, Diaphnocoris chlorionis (Say); and the leafhoppers (Macropsis fumipennis (Gillette & Baker), Stragania alabamensis (Baker), Empoasca fabae (Harris) (potato leafhopper), and Erythroneura clavata DeLong. The beating tray method was generally more effective in capturing early instars, which may be protected from D-vac suction by their small size and the unfolding leaflets in which they feed. The D-vac method was more effective for sampling the more active adult stage of leafhoppers. Our study illustrates the importance of evaluating the effectiveness of a particular technique for monitoring different species and different stages within a species.
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- 1990
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154. Managing magnolia scale.
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HERMS, DANIEL A.
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CONTROL of plant parasites ,MAGNOLIAS ,HOST plants ,INSECTICIDES ,PEST control ,MANAGEMENT - Abstract
The article provides ways on how to manage magnolia scale, a pest of magnolias in nurseries and landscapes. Details on the life cycle of the magnolia scale and the damages it can cause to its host are offered as well as its proper pest management. It notes that successful management of magnolia scale can be challenging but it is possible through vigilant monitoring program combined with judicious use of well-timed insecticides.
- Published
- 2009
155. Hold off on treating ash trees with insecticides - for now.
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HERMS, DANIEL A.
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INSECTICIDES ,BORERS (Insects) ,TREE diseases & pests ,PLANT health ,HORTICULTURE - Abstract
Discusses whether preventive insecticide applications are necessary in Ohio to protect ash trees from emerald ash borer infestation. Consideration of interaction between biology of the insect and regulatory issues; Devastation of the pest; Recommendation for removal and destruction of infested trees.
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- 2004
156. Interspecific Comparison of Constitutive Ash Phloem Phenolic Chemistry Reveals Compounds Unique to Manchurian Ash, a Species Resistant to Emerald Ash Borer.
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Whitehill, Justin, Opiyo, Stephen, Koch, Jennifer, Herms, Daniel, Cipollini, Donald, and Bonello, Pierluigi
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PHLOEM , *ASH (Combustion product) , *PLANT parasites , *ETHYLBENZENE , *EMERALD ash borer - Abstract
The emerald ash borer ( Agrilus planipennis, EAB) is an invasive wood-borer indigenous to Asia and is responsible for widespread ash ( Fraxinus spp.) mortality in the U.S. and Canada. Resistance and susceptibility to EAB varies among Fraxinus spp., which is a result of their co-evolutionary history with the pest. We characterized constitutive phenolic profiles and lignin levels in the phloem of green, white, black, blue, European, and Manchurian ash. Phloem was sampled twice during the growing season, coinciding with phenology of early and late instar EAB. We identified 66 metabolites that displayed a pattern of variation, which corresponded strongly with phylogeny. Previously identified lignans and lignan derivatives were confirmed to be unique to Manchurian ash, and may contribute to its high level of resistance to EAB. Other compounds that had been considered unique to Manchurian ash, including hydroxycoumarins and the phenylethanoids calceolarioside A and B, were detected in closely related, but susceptible species, and thus are unlikely to contribute to EAB resistance of Manchurian ash. The distinct phenolic profile of blue ash may contribute to its relatively high resistance to EAB. [ABSTRACT FROM AUTHOR]
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- 2012
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157. Impacts of emerald ash borer-induced tree mortality on leaf litter arthropods and exotic earthworms
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Ulyshen, Michael D., Klooster, Wendy S., Barrington, William T., and Herms, Daniel A.
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FOOD chains , *INTRODUCED species , *EMERALD ash borer , *TREE mortality , *INSECT-plant relationships , *PLANT-soil relationships - Abstract
Abstract: Because leaf litter occurs at the interface between the soil and atmosphere, the invertebrates inhabiting it represent important linkages between above- and below-ground food webs. The responses of these organisms to forest disturbance brought about by invasive species should therefore have far-reaching ecological effects. The purpose of this study was to explore how canopy gap formation (gap fraction 1–10%) and fallen ash trees (“logs”) resulting from extensive (>99%) ash tree mortality caused by the invasive emerald ash borer (EAB) affect the distributions of litter-dwelling arthropods and earthworms. These organisms did not vary in abundance across the gap fraction range studied but, as predicted from the literature, many taxa (e.g., Aranea, Coleoptera, Collembola, Diplopoda, Isopoda, Opiliones and exotic earthworms) were more abundant next to logs than away from them. Contrary to expectations, arthropods did not become more concentrated next to logs as canopy openness increased, with isopods exhibiting the opposite response. These results suggest litter-dwelling arthropods in EAB-infested forests are favored by inputs of ash wood to the forest floor but are largely unaffected by increases in canopy openness, at least across the gap fraction range studied. [Copyright &y& Elsevier]
- Published
- 2011
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158. Distinguishing Defensive Characteristics in the Phloem of Ash Species Resistant and Susceptible to Emerald Ash Borer.
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Cipollini, Don, Qin Wang, Whitehill, Justin G. A., Powell, Jeff R., Bonello, Pierluigi, and Herms, Daniel A.
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ASH (Tree) , *EMERALD ash borer , *AGRILUS , *PHLOEM , *TRYPSIN , *PHENOLS - Abstract
We examined the extent to which three Fraxinus cultivars and a wild population that vary in their resistance to Emerald Ash Borer (EAB) could be differentiated on the basis of a suite of constitutive chemical defense traits in phloem extracts. The EAB-resistant Manchurian ash ( F. mandshurica, cv. Mancana) was characterized by having a rapid rate of wound browning, a high soluble protein concentration, low trypsin inhibitor activities, and intermediate levels of peroxidase activity and total soluble phenolic concentration. The EAB-susceptible white ash ( F. americana, cv. Autumn Purple) was characterized by a slow wound browning rate and low levels of peroxidase activity and total soluble phenolic concentrations. An EAB-susceptible green ash cultivar ( F. pennsylvanica, cv. Patmore) and a wild accession were similar to each other on the basis of several chemical defense traits, and were characterized by high activities of peroxidase and trypsin inhibitor, a high total soluble phenolic concentration, and an intermediate rate of wound browning. Lignin concentration and polyphenol oxidase activities did not differentiate resistant and susceptible species. Of 33 phenolic compounds separated by HPLC and meeting a minimum criterion for analysis, nine were unique to Manchurian ash, five were shared among all species, and four were found in North American ashes and not in the Manchurian ash. Principal components analysis revealed clear separations between Manchurian, white, and green ashes on the basis of all phenolics, as well as clear separations on the basis of quantities of phenolics that all species shared. Variation in some of these constitutive chemical defense traits may contribute to variation in resistance to EAB in these species. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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159. Phylogenetic risk assessment is robust for forecasting the impact of European insects on North American conifers.
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Uden DR, Mech AM, Havill NP, Schulz AN, Ayres MP, Herms DA, Hoover AM, Gandhi KJK, Hufbauer RA, Liebhold AM, Marsico TD, Raffa KF, Thomas KA, Tobin PC, and Allen CR
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- Animals, Phylogeny, Insecta, Plants, Introduced Species, Ecosystem, Tracheophyta
- Abstract
Some introduced species cause severe damage, although the majority have little impact. Robust predictions of which species are most likely to cause substantial impacts could focus efforts to mitigate those impacts or prevent certain invasions entirely. Introduced herbivorous insects can reduce crop yield, fundamentally alter natural and managed forest ecosystems, and are unique among invasive species in that they require certain host plants to succeed. Recent studies have demonstrated that understanding the evolutionary history of introduced herbivores and their host plants can provide robust predictions of impact. Specifically, divergence times between hosts in the native and introduced ranges of a nonnative insect can be used to predict the potential impact of the insect should it establish in a novel ecosystem. However, divergence time estimates vary among published phylogenetic datasets, making it crucial to understand if and how the choice of phylogeny affects prediction of impact. Here, we tested the robustness of impact prediction to variation in host phylogeny by using insects that feed on conifers and predicting the likelihood of high impact using four different published phylogenies. Our analyses ranked 62 insects that are not established in North America and 47 North American conifer species according to overall risk and vulnerability, respectively. We found that results were robust to the choice of phylogeny. Although published vascular plant phylogenies continue to be refined, our analysis indicates that those differences are not substantial enough to alter the predictions of invader impact. Our results can assist in focusing biosecurity programs for conifer pests and can be more generally applied to nonnative insects and their potential hosts by prioritizing surveillance for those insects most likely to be damaging invaders., (© 2022 The Ecological Society of America. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)
- Published
- 2023
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160. Application of somatic embryogenesis for development of emerald ash borer-resistant white ash and green ash varietals.
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Merkle SA, Koch JL, Tull AR, Dassow JE, Carey DW, Barnes BF, Richins MWM, Montello PM, Eidle KR, House LT, Herms DA, and Gandhi KJK
- Abstract
Emerald ash borer ( Agrilus planipennis ; EAB) has devastated populations of ash ( Fraxinus spp.) trees in dozens of U.S. states and Canada over the past few decades. The continued survival of scattered ash trees known as "lingering ash" in heavily infested natural stands, however, offers evidence of genetic resistance or tolerance to EAB. These surviving or "lingering" ash individuals may form the basis for reforestation programs in EAB-impacted areas, and clonal mass-propagation of these genotypes can help accelerate these efforts. Between 2013 and 2018, we initiated embryogenic cultures by culturing immature zygotic embryos from open-pollinated (OP) seeds collected from several surviving white ash and green ash trees in Michigan and Pennsylvania. In addition, in 2018, we initiated cultures from crosses made between lingering green ash parents from the USDA Forest Service ash breeding program in Ohio. Somatic embryos were produced by growing cultures in liquid suspension, followed by fractionation and plating on semisolid medium to produce developmentally synchronous populations of somatic embryos. Somatic embryo germination and conversion were enhanced by a combination of pre-germination cold treatment and inclusion of activated charcoal and gibberellic acid in the germination medium. Ash somatic seedlings derived from OP explants grew rapidly following transfer to potting mix and somatic seedlings representing nine ash clones were acclimatized, grown in the greenhouse and planted in a preliminary field test, along with EAB-resistant Manchurian ash ( F. mandshurica ) and EAB-susceptible control seedlings. Somatic seedlings have now been produced from cultures that originated from seeds derived from the progeny of lingering green ash parents and an ex vitro germination protocol has shown some promise for accelerating early somatic seedling growth. Results of this research could provide the basis for scaled-up production of EAB-resistant ash varieties for seed orchard production for forest restoration and cultivar development for urban tree restoration., Competing Interests: Conflict of interestThe authors declare that they have no conflicts of interest., (© The Author(s), under exclusive licence to Springer Nature B.V. 2022.)
- Published
- 2022
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161. Evaluation of Trapping Schemes to Detect Emerald Ash Borer (Coleoptera: Buprestidae).
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Tobin PC, Strom BL, Francese JA, Herms DA, McCullough DG, Poland TM, Ryall KL, Scarr T, Silk PJ, and Thistle HW
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- Animals, Canada, Insect Control, Insecta, Larva, Pheromones, Coleoptera, Fraxinus
- Abstract
Management responses to invasive forest insects are facilitated by the use of detection traps ideally baited with species-specific semiochemicals. Emerald ash borer, Agrilus planipennis Fairmaire, is currently invading North American forests, and since its detection in 2002, development of monitoring tools has been a primary research objective. We compared six trapping schemes for A. planipennis over 2 yr at sites in four U.S. states and one Canadian province that represented a range of background A. planipennis densities, canopy coverage, and ash basal area. We also developed a region-wide phenology model. Across all sites and both years, the 10th, 50th, and 90th percentile of adult flight occurred at 428, 587, and 837 accumulated degree-days, respectively, using a base temperature threshold of 10°C and a start date of 1 January. Most trapping schemes captured comparable numbers of beetles with the exception of purple prism traps (USDA APHIS PPQ), which captured significantly fewer adults. Trapping schemes varied in their trap catch across the gradient of ash basal area, although when considering trap catch as a binary response variable, trapping schemes were more likely to detect A. planipennis in areas with a higher ash component. Results could assist managers in optimizing trap selection, placement, and timing of deployment given local weather conditions, forest composition, and A. planipennis density., (© The Author(s) 2021. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2021
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162. Determinants and consequences of plant-insect phenological synchrony for a non-native herbivore on a deciduous conifer: implications for invasion success.
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Ward SF, Moon RD, Herms DA, and Aukema BH
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- Animals, Insecta, North America, Plants, Seasons, Herbivory, Tracheophyta
- Abstract
Phenological synchrony between herbivorous insects and host plants is an important determinant of insect distribution and abundance. Non-native insects often experience novel climates, photoperiods, and host plants. How critical time periods of insect life cycles coincide with-or diverge from-phenological windows of host plant suitability could affect invasion success and the dynamics of outbreaks. Larch casebearer is an invasive defoliator that has recently undergone anomalous outbreaks on eastern larch in North America. We conducted growth chamber, greenhouse, and field studies to quantify the spring phenological window for larch casebearer on eastern larch and importance of phenological synchrony for casebearer development and survival. We constructed degree-day models of spring activity for both species and investigated responses of casebearers to early and delayed activation relative to bud break. Both species had lower developmental thresholds of ~ 5 °C, but mean activation of casebearers occurred 245 degree-days after bud break by eastern larch. In addition to forcing temperatures, phenologies of eastern larch and casebearer larvae were significantly influenced by chilling and photoperiod, respectively. Larvae were robust to both starvation and delayed activation; days between larval activation and bud break (range: 0-58 days) had no influence on larval development and survival to adulthood. Disparate plant-insect responses to environmental cues and robustness of casebearers to changes in phenology result in a wide phenological window that likely has contributed to the insect's broad distribution in eastern North America. Changes in phenological synchrony, however, do not appear to have facilitated recent outbreaks of larch casebearer on eastern larch.
- Published
- 2019
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163. Variation in the Volatile Profiles of Black and Manchurian Ash in Relation to Emerald Ash Borer Oviposition Preferences.
- Author
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Rigsby CM, McCartney NB, Herms DA, Tumlinson JH, and Cipollini D
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- Acyclic Monoterpenes, Animals, Female, Fraxinus metabolism, Gas Chromatography-Mass Spectrometry, Monocyclic Sesquiterpenes, Monoterpenes chemistry, Monoterpenes pharmacology, Oviposition drug effects, Plant Bark chemistry, Plant Bark metabolism, Plant Leaves chemistry, Plant Leaves metabolism, Polycyclic Sesquiterpenes, Sesquiterpenes chemistry, Sesquiterpenes pharmacology, Volatile Organic Compounds pharmacology, Coleoptera physiology, Fraxinus chemistry, Volatile Organic Compounds chemistry
- Abstract
Emerald ash borer (EAB; Agrilus planipennis) is a devastating pest of ash (Fraxinus spp.) in its invaded range in North America. Its coevolved Asian hosts are more resistant and less preferred for oviposition than susceptible North American species. We compared EAB oviposition preferences and bark and canopy volatile organic compound (VOC) emissions of resistant Manchurian ash and susceptible black ash, and examined relationships between VOC profiles and oviposition. In the field, black ash was highly preferred for oviposition while no eggs were laid on Manchurian ash, and we found clear differences in the VOC profiles of Manchurian and black ash. We detected 78 compounds emitted from these species, including 16 compounds that elicited EAB antennal activity in prior studies. Four compounds were unique to black and 11 to Manchurian ash. Emission rates of 14 canopy and 19 bark volatiles varied among the two species, including four previously reported as antennally active. Specifically, 7-epi-sesquithujene (bark) emissions were greater from black ash, while β-caryophyllene (canopy), linalool (bark), and α-cubebene (bark) were emitted at higher rates by Manchurian ash. No relationships were found between the emission rate of any single compound or group of compounds (e.g. monoterpenes) suggesting that preference may be based on complex profile combinations. This is the first study to directly compare VOCs of black and Manchurian ash as well as the first to examine bark- and canopy-specific VOCs. The unique bark and canopy VOC profiles of these two species implicates potentially important variation in VOCs between a closely related resistant and susceptible species that provides a foundation for future studies of host preferences of EAB.
- Published
- 2017
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164. Higher Activities of Defense-Associated Enzymes may Contribute to Greater Resistance of Manchurian Ash to Emerald Ash Borer Than A closely Related and Susceptible Congener.
- Author
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Rigsby CM, Herms DA, Bonello P, and Cipollini D
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- Animals, Fraxinus chemistry, Fraxinus physiology, Hydrogen Peroxide metabolism, Species Specificity, Trypsin Inhibitors metabolism, Water chemistry, Coleoptera, Enzymes chemistry, Enzymes metabolism, Fraxinus enzymology
- Abstract
Emerald ash borer (EAB) is an invasive beetle native to Asia that infests and kills ash (Fraxinus spp.) in North America. Previous experiments indicated that larvae feeding on co-evolved, resistant Manchurian ash (F. mandshurica) have increased antioxidant and quinone-protective enzyme activities compared to larvae feeding on susceptible North American species. Here, we examined mechanisms of host-generated oxidative and quinone-based stress and other putative defenses in Manchurian ash and the closely related and chemically similar, but susceptible, black ash (F. nigra), with and without exogenous application of methyl jasmonate (MeJA) to induce resistance mechanisms. Peroxidase activities were 4.6-13.3 times higher in Manchurian than black ash, although both species appeared to express the same three peroxidase isozymes. Additionally, peroxidase-mediated protein cross-linking activity was stronger in Manchurian ash. Polyphenol oxidase, β-glucosidase, chitinase, and lipoxygenase activities also were greater in Manchurian ash, but only lipoxygenase activity increased with MeJA application. Phloem H
2 O2 levels were similar and were increased by MeJA application in both species. Lastly, trypsin inhibitor activity was detected in methanol and water extracts that were not allowed to oxidize, indicating the presence of phenolic-based trypsin inhibitors. However, no proteinaceous trypsin inhibitor activity was detected in either species. In response to MeJA application, Manchurian ash had higher trypsin inhibitor activity than black ash using the unoxidized water extracts, but no treatment effects were detected using methanol extracts. Based on these results we hypothesize that peroxidases, lignin polymerization, and quinone generation contribute to the greater resistance to EAB displayed by Manchurian ash.- Published
- 2016
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165. Decreased emergence of emerald ash borer from ash treated with methyl jasmonate is associated with induction of general defense traits and the toxic phenolic compound verbascoside.
- Author
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Whitehill JG, Rigsby C, Cipollini D, Herms DA, and Bonello P
- Subjects
- Adaptation, Physiological, Animals, Fraxinus metabolism, Fraxinus physiology, Glucosides pharmacology, Larva drug effects, Larva growth & development, Lignin metabolism, Lignin pharmacology, North America, Phenols pharmacology, Species Specificity, Trypsin Inhibitors metabolism, Trypsin Inhibitors pharmacology, Acetates pharmacology, Coleoptera drug effects, Coleoptera growth & development, Cyclopentanes pharmacology, Disease Resistance drug effects, Fraxinus drug effects, Glucosides metabolism, Insecticides pharmacology, Oxylipins pharmacology, Phenols metabolism, Plant Growth Regulators pharmacology
- Abstract
The emerald ash borer (EAB; Agrilus planipennis Fairmaire) is causing widespread mortality of ash (Fraxinus spp.) in North America. To date, no mechanisms of host resistance have been identified against this pest. Methyl jasmonate was applied to susceptible North American and resistant Asian ash species to determine if it can elicit induced responses in bark that enhance resistance to EAB. In particular, phenolic compounds, lignin, and defense-related proteins were quantified, and compounds associated with resistance were subsequently tested directly against EAB larvae in bioassays with artificial diet. MeJA application decreased adult emergence in susceptible ash species, comparable to levels achieved by insecticide application. Concentration of the phenolic compound verbascoside sharply increased after MeJA application to green and white ash. When incorporated in an artificial diet, verbascoside decreased survival and growth of EAB neonates in a dose-dependent fashion. Lignin and trypsin inhibitors were also induced by MeJA, and analogs of both compounds reduced growth of EAB larvae in artificial diets. We conclude that the application of MeJA prior to EAB attack has the ability to enhance resistance of susceptible ash trees by inducing endogenous plant defenses, and report evidence that induction of verbascoside is a mechanism of resistance to EAB.
- Published
- 2014
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166. Antioxidant genes of the emerald ash borer (Agrilus planipennis): gene characterization and expression profiles.
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Rajarapu SP, Mamidala P, Herms DA, Bonello P, and Mittapalli O
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- Amino Acid Sequence, Animals, Base Sequence, Coleoptera chemistry, Coleoptera metabolism, Expressed Sequence Tags, Insect Proteins chemistry, Insect Proteins metabolism, Molecular Sequence Data, Plant Diseases parasitology, Sequence Alignment, Antioxidants metabolism, Coleoptera enzymology, Coleoptera genetics, Fraxinus parasitology, Gene Expression Profiling, Insect Proteins genetics
- Abstract
Phytophagous insects frequently encounter reactive oxygen species (ROS) from exogenous and endogenous sources. To overcome the effect of ROS, insects have evolved a suite of antioxidant defense genes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione peroxidase (GPX). The emerald ash borer (Agrilus planipennis Fairmaire), an exotic invasive insect pest from Asia has killed millions of ash trees and continues to invade North America at a rapid pace. From an on-going expressed sequence tag (EST) project of A. planipennis larval tissues, we identified ESTs coding for a Cu-Zn SOD (ApSOD1), a CAT (ApCAT1) and a GPX (ApGPX1). A multiple sequence alignment of the derived A. planipennis sequences revealed high homology with other insect sequences at the amino acid level. Phylogenetic analysis of ApSOD1 grouped it with Cu-Zn SODs of other insect taxa. Quantitative real time PCR (qRT-PCR) analysis in different larval tissues (midgut, fat body, Malpighian tubule and cuticle) revealed high mRNA levels of ApCAT1 in the midgut. Interestingly, high mRNA levels for both ApSOD1 and ApGPX1 were observed in the Malpighian tubules. Assay of mRNA levels in developmental stages (larva, prepupa and adults) by qRT-PCR indicated high transcript levels of ApCAT1 and ApGPX1 in larval and prepupal stages with a decline in adults. On the other hand, the transcript levels of ApSOD1 were observed to be constitutive in all the developmental stages assayed. Results obtained reflect a plausible role of these A. planipennis antioxidant genes in quenching ROS from both diet (ash allelochemicals) as well as endogenous sources. These studies further help in understanding the adaptation/invasiveness of A. planipennis., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
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167. Effects of soil type, fertilization and drought on carbon allocation to root growth and partitioning between secondary metabolism and ectomycorrhizae of Betula papyrifera.
- Author
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Kleczewski NM, Herms DA, and Bonello P
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- Betula metabolism, Betula microbiology, Fertilizers, Water metabolism, Betula growth & development, Carbon metabolism, Droughts, Mycorrhizae physiology, Plant Roots metabolism, Soil analysis
- Abstract
Paper birch (Betula papyrifera Marsh) seedlings were grown in a greenhouse in either subsoil or topsoil in factorial combination with two fertilization and drought regimes to investigate how different soil environments and nutrient availability drive belowground partitioning between growth, secondary metabolism and ectomycorrhizal (EM) associations, and impact drought tolerance of paper birch. Root and total seedling dry biomass, starch, soluble sugars, soluble phenolics, lignin and EM abundance were quantified. In unfertilized topsoil, total plant biomass and root biomass were approximately nine times higher than in unfertilized subsoil, but the root weight ratios did not differ between soils. Root soluble phenolics and lignin were higher in unfertilized subsoil than in unfertilized topsoil, whereas EM abundance was significantly higher in unfertilized topsoil than in unfertilized subsoil. In topsoil, fertilization decreased root biomass and EM abundance and increased root phenolics and lignin. In contrast, fertilization of subsoil increased root biomass but decreased root phenolics and lignin, while EM abundance was unaffected. In both soil types, fertilization reduced root weight ratios. Across soil types, EM abundance was negatively correlated with root soluble sugars, root phenolics and lignin, but this was driven mainly by the responses in the topsoil treatment. Our results show that soil fertility mediates carbon tradeoffs among defense, growth and EM associations.
- Published
- 2010
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168. Effects of fertilization and fungal and insect attack on systemic protein defenses of austrian pine.
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Barto K, Enright S, Eyles A, Wallis C, Chorbadjian R, Hansen R, Herms DA, Bonello P, and Cipollini D
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- Animals, Catechol Oxidase metabolism, Chitinases metabolism, Host-Pathogen Interactions, Nutritive Value, Peroxidase metabolism, Phloem metabolism, Pinus microbiology, Pinus parasitology, Trypsin Inhibitors metabolism, Ascomycota pathogenicity, Hymenoptera pathogenicity, Pinus metabolism, Plant Proteins metabolism, Soil
- Abstract
Despite their economic and ecological importance, defense responses of conifers to pests are little understood. In a 3-year experiment, we monitored systemic fungal (Diplodia pinea)- and insect (Neodiprion sertifer)-induced defense protein activities and total soluble proteins in needles and phloem of Austrian pine (Pinus nigra) across a soil fertility gradient. In both years, total soluble protein content of foliage and phloem declined with increasing fertility across induction treatments, while defensive protein activities generally increased with increasing fertility. In 2005, total soluble protein content in branch phloem was increased by fungal inoculation of the stem. Peroxidase activity was suppressed in needles by insect defoliation in 2006, while polyphenol oxidase activity was systemically induced in branch phloem by insect attack in 2005. Trypsin inhibitor activities in phloem did not respond to any induction or fertility treatment. Nutritive quality of Austrian pine tissue declined with increasing fertility, while several protein-based defenses simultaneously increased.
- Published
- 2008
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169. Comparative phloem chemistry of Manchurian (Fraxinus mandshurica) and two North American ash species (Fraxinus americana and Fraxinus pennsylvanica).
- Author
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Eyles A, Jones W, Riedl K, Cipollini D, Schwartz S, Chan K, Herms DA, and Bonello P
- Subjects
- Chromatography, High Pressure Liquid, Magnetic Resonance Spectroscopy, Species Specificity, Spectrometry, Mass, Electrospray Ionization, Spectrophotometry, Ultraviolet, Fraxinus chemistry, Phloem chemistry
- Abstract
Recent studies have investigated interspecific variation in resistance of ash (Fraxinus spp.) to the exotic wood-boring beetle, emerald ash borer (EAB, Agrilus planipennis). Manchurian ash (Fraxinus mandshurica) is an Asian species that has coevolved with EAB. It experiences little EAB-induced mortality compared to North American ashes. Host phloem chemistry, both constitutive and induced, might partly explain this interspecific variation in resistance. We analyzed the constitutive phloem chemistry of three ash species: Manchurian ash and North American white (Fraxinus americana) and green (Fraxinus pennsylvanica) ash. Analysis of the crude phloem extracts revealed the presence of an array of phenolic compounds including hydroxycoumarins, a monolignol, lignans, phenylethanoids, and secoiridoids. Both qualitative and quantitative differences were observed among the three ash species. Hydroxycoumarins and the phenylethanoids, calceloariosides A and B, were present only in the phloem of Manchurian ash and might represent a mechanism of resistance against EAB.
- Published
- 2007
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170. Testing the growth-differentiation balance hypothesis: dynamic responses of willows to nutrient availability.
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Glynn C, Herms DA, Orians CM, Hansen RC, and Larsson S
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- Biomass, Fertilizers, Plant Leaves metabolism, Random Allocation, Salix metabolism, Phenols metabolism, Phenylpropionates metabolism, Plant Leaves growth & development, Salix growth & development, Tannins metabolism
- Abstract
Here, the growth-differentiation balance hypothesis (GDBH) was tested by quantifying temporal variation in the relative growth rate (RGR), net assimilation rate (NAR), and phenylpropanoid concentrations of two willow species (Salix sericea and Salix eriocephala) across five fertility levels. Initially, RGR increased and total phenylpropanoids declined (although every individual phenolic did not) as fertility increased, but NAR was unaffected. Subsequently, NAR and phenylpropanoids declined in the low fertility treatment, generating a quadratic response of secondary metabolism across the nutrient gradient. As above- and below-ground growth rates equilibrated, NAR and phenylpropanoids increased in the low fertility treatment, re-establishing a negative linear effect of fertility on secondary metabolism. A transient quadratic response of secondary metabolism is predicted when GDBH is integrated with models of optimal phenotypic plasticity, occurring when low NAR imposes carbon constraints on secondary metabolism in low nutrient environments. Once plants acclimate to nutrient limitation, the equilibrium allocation state is predicted to be a negative correlation between growth and secondary metabolism. Although both willow species generally responded according to GDBH, the complexity observed suggests that prediction of the effects of nutrient availability on secondary metabolism (and other plastic responses) in specific cases requires a priori knowledge of the physiological status of the plant and soil nutrient availability.
- Published
- 2007
- Full Text
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171. Effects of drought stress and nutrient availability on dry matter allocation, phenolic glycosides, and rapid induced resistance of poplar to two lymantriid defoliators.
- Author
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Hale BK, Herms DA, Hansen RC, Clausen TP, and Arnold D
- Subjects
- Animals, Carbon chemistry, Carbon metabolism, Glycosides chemistry, Larva growth & development, Nutritive Value, Phenols chemistry, Plant Leaves chemistry, Plant Leaves growth & development, Population Dynamics, Populus chemistry, Populus physiology, Species Specificity, Time Factors, Disasters, Host-Parasite Interactions physiology, Moths physiology, Phenols metabolism, Populus metabolism
- Abstract
The growth-differentiation balance hypothesis (GDBH) postulates that variation in resource availability can increase or decrease allocation to secondary metabolism, depending on how growth is affected relative to carbon assimilation. Growth and leaf area of black poplar (Populus nigra) increased substantially in response to increased nutrient availability, while net assimilation rate and photosynthesis were less strongly affected. In response, total phenolic glycoside concentrations declined, which is consistent with GDBH. Drought stress decreased net assimilation rate and photosynthesis as well as growth, while increasing total phenolic glycoside concentrations. This pattern does not follow GDBH, which predicts lower secondary metabolism when resource limitation decreases both growth and carbon assimilation. However, there was a strong negative correlation between growth and total phenolic glycoside concentration consistent with a trade-off between primary and secondary metabolism, a key premise of GDBH. Drought decreased the growth of gypsy moth (Lymantria dispar) larvae but had no effect on whitemarked tussock moth (Orgyia leucostigma). Increased nutrient availability had a positive linear effect on growth of whitemarked tussock moth, but no effect on gypsy moth. Treatment effects on gypsy moth corresponded closely with effects on total phenolic glycosides, whereas effects on whitemarked tussock moth more closely tracked changes in nutritional quality. Localized gypsy moth herbivory elicited rapid induced resistance to gypsy moth, with the effect being independent of water and nutrient availability, but did not affect whitemarked tussock moth, indicating that the effects of biotic and abiotic stress on insect resistance of trees can be species-specific.
- Published
- 2005
- Full Text
- View/download PDF
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