News Article | April 20, 2017
Since the pernicious pest arrived in the United States nearly 20 years ago, it has proven difficult to fend off, attacking crops in the summer and invading homes in the fall and winter. And, as a team of researchers has recently found, one of the leading monitoring methods for the stink bug may only be effective for half of the year. A study set to be published next week in the Entomological Society of America's Journal of Economic Entomology shows that traps baited with the aggregation pheromone of the brown marmorated stink bug (Halyomorpha halys) are not reliable at attracting the insect during its overwintering period, from late fall to early spring. "Just eight to 20 percent of the stink bugs we saw crawling around hallways were captured," says Rob Morrison, Ph.D., research entomologist at the Unite States Department of Agriculture's Agricultural Research Service (USDA-ARS) and lead author on the study, which tested the traps in infested homes in 2014 and 2016. The reason, they found, is that the brown marmorated stink bug does not respond to its aggregation pheromone—a chemical signal that insects release into the air—until daylight lengthens to approximately 13.5 hours each day, roughly late April to early May in the United States. Thus, traps baited with the pheromone leave overwintering stink bugs largely unfazed. Morrison and fellow entomologists at the USDA-ARS Appalachian Fruit Research Station, Virginia Tech University, and North Carolina State University deployed traps in both heated and unheated structures and outside in locations in Virginia, West Virginia, and North Carolina and monitored their performance with weekly counts of stink bugs both trapped and visible nearby. Not only did they find that the traps caught a small fraction of the stink bugs, but the minimal rate at which the insects were trapped was also not correlated with the overall ups and downs in their numbers at each location, meaning the traps aren't reliable for monitoring purposes either. The results mean that, for homeowners trying to use traps to capture stink bugs in their homes, prevention is key, because once stink bugs are inside, pheromone traps likely won't be much help. "To prevent brown marmorated stink bugs from gaining access to your house, seal all holes and cracks, including where the roof meets the structure, and where the house meets the foundation," Morrison says. The research team note in their study that their findings also raise concerns for preventing the further spread of the brown marmorated stink bug, which can hitch rides in shipments of produce around the world. The key question is whether a pheromone trap at a port in the southern hemisphere in summer, for instance, will intercept stink bugs that have just been shipped out of their overwintering period in the northern hemisphere. While Halyomorpha halys may have won this round, Morrison says he and his colleagues will press on. "The brown marmorated stink bug may rely on a yet-to-be-identified chemical stimulus or other communication method during the fall when they disperse to overwintering sites and when they emerge during the spring," says Morrison. "Both are areas of active research." Explore further: Stink bug traps may increase damage to tomato fruits More information: William R. Morrison et al, Behavioral Response of the Brown Marmorated Stink Bug (Hemiptera: Pentatomidae) to Semiochemicals Deployed Inside and Outside Anthropogenic Structures During the Overwintering Period, Journal of Economic Entomology (2017). DOI: 10.1093/jee/tox097
Malnoy M.,Research and Innovation Center |
Martens S.,Research and Innovation Center |
Norelli J.L.,Appalachian Fruit Research Station |
Barny M.-A.,French National Institute for Agricultural Research |
And 3 more authors.
Annual Review of Phytopathology | Year: 2012
The enterobacterial phytopathogen Erwinia amylovora causes fire blight, an invasive disease that threatens a wide range of commercial and ornamental Rosaceae host plants. The response elicited by E. amylovora in its host during disease development is similar to the hypersensitive reaction that typically leads to resistance in an incompatible host-pathogen interaction, yet no gene-for-gene resistance has been described for this host-pathogen system. Comparative genomic analysis has found an unprecedented degree of genetic uniformity among strains of E. amylovora, suggesting that the pathogen has undergone a recent genetic bottleneck. The genome of apple, an important host of E. amylovora, has been sequenced, creating new opportunities for the study of interactions between host and pathogen during fire blight development and for the identification of resistance genes. This review includes recent advances in the genomics of both host and pathogen. © 2012 by Annual Reviews. All rights reserved.
Dardick C.D.,Appalachian Fruit Research Station |
Callahan A.M.,Appalachian Fruit Research Station |
Chiozzotto R.,University of Milan |
Schaffer R.J.,New Zealand Institute for Plant and Food Research |
And 2 more authors.
BMC Biology | Year: 2010
Background: Lignification of the fruit endocarp layer occurs in many angiosperms and plays a critical role in seed protection and dispersal. This process has been extensively studied with relationship to pod shatter or dehiscence in Arabidopsis. Dehiscence is controlled by a set of transcription factors that define the fruit tissue layers and whether or not they lignify. In contrast, relatively little is known about similar processes in other plants such as stone fruits which contain an extremely hard lignified endocarp or stone surrounding a single seed.Results: Here we show that lignin deposition in peach initiates near the blossom end within the endocarp layer and proceeds in a distinct spatial-temporal pattern. Microarray studies using a developmental series from young fruits identified a sharp and transient induction of phenylpropanoid, lignin and flavonoid pathway genes concurrent with lignification and subsequent stone hardening. Quantitative polymerase chain reaction studies revealed that specific phenylpropanoid (phenylalanine ammonia-lyase and cinnamate 4-hydroxylase) and lignin (caffeoyl-CoA O-methyltransferase, peroxidase and laccase) pathway genes were induced in the endocarp layer over a 10 day time period, while two lignin genes (p-coumarate 3-hydroxylase and cinnamoyl CoA reductase) were co-regulated with flavonoid pathway genes (chalcone synthase, dihydroflavanol 4-reductase, leucoanthocyanidin dioxygen-ase and flavanone-3-hydrosylase) which were mesocarp and exocarp specific. Analysis of other fruit development expression studies revealed that flavonoid pathway induction is conserved in the related Rosaceae species apple while lignin pathway induction is not. The transcription factor expression of peach genes homologous to known endocarp determinant genes in Arabidopsis including SHATTERPROOF, SEEDSTCK and NAC SECONDARY WALL THICENING PROMOTING FACTOR 1 were found to be specifically expressed in the endocarp while the negative regulator FRUITFUL predominated in exocarp and mesocarp.Conclusions: Collectively, the data suggests, first, that the process of endocarp determination and differentiation in peach and Arabidopsis share common regulators and, secondly, reveals a previously unknown coordination of competing lignin and flavonoid biosynthetic pathways during early fruit development. © 2010 Dardick et al; licensee BioMed Central Ltd.
Interactions between extrafloral nectaries, ants (Hymenoptera: Formicidae), and other natural enemies affect biological control of grapholita molesta (Lepidoptera: Tortricidae) on peach (Rosales: Rosaceae)
Mathews C.R.,University of Maryland University College |
Mathews C.R.,Shepherd University |
Bottrell D.G.,University of Maryland University College |
Brown M.W.,Appalachian Fruit Research Station
Environmental Entomology | Year: 2011
Extrafloral nectaries (EFNs) are reported to benefit some plants when ants (Hymenoptera: Formicidae) use their secretions and fend off herbivores, but in some cases resulting competitive interactions may reduce biological control of specific herbivores. This research examined the interactions between ants and other natural enemies associated with the EFNs of peach [Prunus persica (L.) Batcsh] and the implications for biological control of a key pest, the oriental fruit moth [Grapholita molesta (Busck)]. Studies using sentinel G. molesta placed on peach trees ('â€̃Lovell'â€™ cultivar) with EFNs present and absent revealed that several natural enemy groups associated with the EFNs contribute to reductions in G. molesta eggs, larvae, and pupae in peach orchards. Ants on trees with EFNs antagonized the G. molesta egg parasitoid Trichogramma minutum (Riley), but the ants were crucial in reducing G. molesta in both the larval and pupal stages. Overall, individual trees with EFNs experienced higher ant and other (nonant) natural enemy densities and subsequent pest reductions, as compared with trees without EFNs. However, the implications of EFN-natural enemypest interactions to orchard-level biological control will likely depend on local G. molesta population dynamics. © 2011 Entomological Society of America.
Brown M.W.,Appalachian Fruit Research Station |
Mathews C.R.,Shepherd University |
Krawczyk G.,Pennsylvania State University
Journal of Economic Entomology | Year: 2010
A common goal of conservation biological control is to enhance biodiversity and increase abundance and effectiveness of predators and parasitoids. Although many studies report an increase in abundance of natural enemies, it has been difficult to document increases in rates of biological control. To enhance parasitism of the tufted apple bud moth, Platynota idaeusalis (Walker) (Lepidoptera: Tortricidae), alternate food was provided by interplanting peaches bearing extrafloral nectaries into apple (Malus spp.) orchards. Laboratory studies showed that the presence of nectar increased longevity and parasitism rates by Goniozus floridanus (Bethylidae), the dominant parasitoid of tufted apple bud moth in West Virginia. In orchard studies, we found the total number of hymenopteran parasitoids was higher on peach (Prunus spp.) trees than on adjacent apple trees. Abundance of parasitic Hymenoptera also was significantly higher on the side of traps facing away from rather than toward peach trees, indicating attraction to peach trees. However, total parasitism rates of tufted apple bud moth were not affected by the presence of peach extrafloral nectar in any field studies. Insect injury to fruit at harvest showed that fruit from orchards with interplanted peach trees had less injury from San Jose scale, Quadraspidiotus perniciosus (Comstock) and stink bugs (Pentatomidae) than fruit from an apple monoculture. Although interplanting with peach trees did not produce the hypothesized result of increased biological control, the experiment did have beneficial results for pest management. These results demonstrate the importance of collecting data on variables beyond the targeted species when evaluating habitat manipulation experiments to fully assess the impact on the ecosystem. © 2010 Entomological Society of America.
Xia R.,Virginia Polytechnic Institute and State University |
Xia R.,Appalachian Fruit Research Station |
Zhu H.,Virginia Polytechnic Institute and State University |
Zhu H.,Appalachian Fruit Research Station |
And 4 more authors.
Genome Biology | Year: 2012
Background: MicroRNAs (miRNAs) and their regulatory functions have been extensively characterized in model species but whether apple has evolved similar or unique regulatory features remains unknown.Results: We performed deep small RNA-seq and identified 23 conserved, 10 less-conserved and 42 apple-specific miRNAs or families with distinct expression patterns. The identified miRNAs target 118 genes representing a wide range of enzymatic and regulatory activities. Apple also conserves two TAS gene families with similar but unique trans-acting small interfering RNA (tasiRNA) biogenesis profiles and target specificities. Importantly, we found that miR159, miR828 and miR858 can collectively target up to 81 MYB genes potentially involved in diverse aspects of plant growth and development. These miRNA target sites are differentially conserved among MYBs, which is largely influenced by the location and conservation of the encoded amino acid residues in MYB factors. Finally, we found that 10 of the 19 miR828-targeted MYBs undergo small interfering RNA (siRNA) biogenesis at the 3' cleaved, highly divergent transcript regions, generating over 100 sequence-distinct siRNAs that potentially target over 70 diverse genes as confirmed by degradome analysis.Conclusions: Our work identified and characterized apple miRNAs, their expression patterns, targets and regulatory functions. We also discovered that three miRNAs and the ensuing siRNAs exploit both conserved and divergent sequence features of MYB genes to initiate distinct regulatory networks targeting a multitude of genes inside and outside the MYB family. © 2012 Xia et al.; licensee BioMed Central Ltd.
Hollender C.A.,Appalachian Fruit Research Station |
Dardick C.,Appalachian Fruit Research Station
New Phytologist | Year: 2015
541 I. 541 II. 542 III. 546 IV. 547 V. 552 552 References 553 Summary: The architecture of trees greatly impacts the productivity of orchards and forestry plantations. Amassing greater knowledge on the molecular genetics that underlie tree form can benefit these industries, as well as contribute to basic knowledge of plant developmental biology. This review describes the fundamental components of branch architecture, a prominent aspect of tree structure, as well as genetic and hormonal influences inferred from studies in model plant systems and from trees with non-standard architectures. The bulk of the molecular and genetic data described here is from studies of fruit trees and poplar, as these species have been the primary subjects of investigation in this field of science. © 2014 New Phytologist Trust.
Janisiewicz W.J.,Appalachian Fruit Research Station
Acta Horticulturae | Year: 2010
Biological control of postharvest decays (BCPD) has been used commercially on pome and citrus fruits since 1996 in the United States, and its use were later expanded to include cherries and seed potatoes. The spectrum of activity of these biocontrol products differs with respect to fruit type and maturity, stage of pathogen infection, and specific pathogen causing decay, and is not as broad as fungicides. Thus, commercial use of BCPD has been targeted for certain commodities and may even be limited to certain postharvest applications within a commodity. Unlike fungicides, currently registered biocontrol products are exempt from residue tolerance by the U.S. Environmental Protection Agency and can be used well into storage even to the point of packing fruit for shipment. Recent research has focused on improving biocontrol itself and/or combining BCPD with other alternative methods to synthetic fungicides. The efficacy of BCPD has been improved by developing antagonist mixtures, and manipulation of growth and formulations of antagonists. Manipulation of biocontrol mechanisms have not yet resulted in improved biocontrol. The potential of foreign antimicrobial genes introduced into antagonists is also being explored. Greater efficacy and broader spectrum of postharvest decay control on fruit was achieved by combining BCPD with heat treatment, GRAS substances, lytic enzymes, or the induction of resistance in fruit by physical or chemical means.
Transcriptomics of shading-induced and NAA-induced abscission in apple (Malus domestica) reveals a shared pathway involving reduced photosynthesis, alterations in carbohydrate transport and signaling and hormone crosstalk
Zhu H.,Virginia Polytechnic Institute and State University |
Dardick C.D.,Appalachian Fruit Research Station |
Beers E.P.,Virginia Polytechnic Institute and State University |
Callanhan A.M.,Appalachian Fruit Research Station |
And 2 more authors.
BMC Plant Biology | Year: 2011
Background: Naphthaleneacetic acid (NAA), a synthetic auxin analogue, is widely used as an effective thinner in apple orchards. When applied shortly after fruit set, some fruit abscise leading to improved fruit size and quality. However, the thinning results of NAA are inconsistent and difficult to predict, sometimes leading to excess fruit drop or insufficient thinning which are costly to growers. This unpredictability reflects our incomplete understanding of the mode of action of NAA in promoting fruit abscission.Results: Here we compared NAA-induced fruit drop with that caused by shading via gene expression profiling performed on the fruit abscission zone (FAZ), sampled 1, 3, and 5 d after treatment. More than 700 genes with significant changes in transcript abundance were identified from NAA-treated FAZ. Combining results from both treatments, we found that genes associated with photosynthesis, cell cycle and membrane/cellular trafficking were downregulated. On the other hand, there was up-regulation of genes related to ABA, ethylene biosynthesis and signaling, cell wall degradation and programmed cell death. While the differentially expressed gene sets for NAA and shading treatments shared only 25% identity, NAA and shading showed substantial similarity with respect to the classes of genes identified. Specifically, photosynthesis, carbon utilization, ABA and ethylene pathways were affected in both NAA- and shading-induced young fruit abscission. Moreover, we found that NAA, similar to shading, directly interfered with leaf photosynthesis by repressing photosystem II (PSII) efficiency within 10 minutes of treatment, suggesting that NAA and shading induced some of the same early responses due to reduced photosynthesis, which concurred with changes in hormone signaling pathways and triggered fruit abscission.Conclusions: This study provides an extensive transcriptome study and a good platform for further investigation of possible regulatory genes involved in the induction of young fruit abscission in apple, which will enable us to better understand the mechanism of fruit thinning and facilitate the selection of potential chemicals for the thinning programs in apple. © 2011 Zhu et al; licensee BioMed Central Ltd.
Dardick C.,Appalachian Fruit Research Station |
Callahan A.M.,Appalachian Fruit Research Station
Frontiers in Plant Science | Year: 2014
Plant evolution is largely driven by adaptations in seed protection and dispersal strategies that allow diversification into new niches. This is evident by the tremendous variation in flowering and fruiting structures present both across and within different plant lineages. Within a single plant family a staggering variety of fruit types can be found such as fleshy fruits including berries, pomes, and drupes and dry fruit structures like achenes, capsules, and follicles. What are the evolutionary mechanisms that enable such dramatic shifts to occur in a relatively short period of time? This remains a fundamental question of plant biology today. On the surface it seems that these extreme differences in form and function must be the consequence of very different developmental programs that require unique sets of genes. Yet as we begin to decipher the molecular and genetic basis underlying fruit form it is becoming apparent that simple genetic changes in key developmental regulatory genes can have profound anatomical effects. In this review, we discuss recent advances in understanding the molecular mechanisms of fruit endocarp tissue differentiation that have contributed to species diversification within three plant lineages. © 2014 Dardick and Callahan.