Is Chinese Tallowtree, Triadica sebifera, an Appropriate Target for Biological Control in the United States?

2014 ◽  
Vol 7 (2) ◽  
pp. 345-359 ◽  
Author(s):  
Gregory S. Wheeler ◽  
Jianqing Ding
Keyword(s):  
United States ◽  
Biological Control ◽  
Management Practices ◽  
Invasive Plant ◽  
Conflicts Of Interest ◽  
The United States ◽  
Great Promise ◽  
Invasive Weed ◽  
Triadica Sebifera ◽  
Regulatory Review

AbstractBiological control is one of the most common approaches used to manage invasive weeds of wetlands and other natural areas. Before candidate agents can be released, research is conducted to support biological control, which can be protracted and expensive, leading to a scientific and potentially lengthy regulatory review. To increase biological control safety, efficacy, and transparency, we suggest that during the early phases of a weed project, the feasibility of the invasive plant as a target should be studied explicitly. Our purpose here is to summarize information of an important invasive weed that can serve to judge whether the project is appropriate. Chinese tallowtree, Triadica sebifera, is one of the worst invasive species invading coastal wetlands and other riparian areas of the southeastern United States. Current management practices have not controlled the spread of this weed into these sensitive habitats. Initial surveys in the plant's native Chinese range for potential biological control agents have recovered several herbivore species that could be developed. These potential agents include defoliators, root and foliage feeders, and gall formers, whose biology, apparent host specificity, and impacts on plant fitness suggest that biological control offers great promise against Chinese tallowtree. When conducted during the initial phase of a project, this type of feasibility study can address potential conflicts of interest and risks, ultimately producing projects that are more effective and safer for biological control.

scholarly journals First Report of Stem Canker of Salsola tragus Caused by Diaporthe eres in Russia

Plant Disease ◽  
2009 ◽  
Vol 93 (1) ◽  
pp. 110-110 ◽  
Author(s):  
T. Kolomiets ◽  
Z. Mukhina ◽  
T. Matveeva ◽  
D. Bogomaz ◽  
D. K. Berner ◽  
...  
Keyword(s):  
United States ◽  
Biological Control ◽  
Biological Control Agent ◽  
Aqueous Suspension ◽  
Stem Canker ◽  
The United States ◽  
Invasive Weed ◽  
Voucher Specimen ◽  
First Report ◽  
Stem Lesions

Salsola tragus L. (Russian thistle) is a problematic invasive weed in the western United States and a target of biological control efforts. In September of 2007, dying S. tragus plants were found along the Azov Sea at Chushka, Russia. Dying plants had irregular, necrotic, canker-like lesions near the base of the stems and most stems showed girdling and cracking. Stem lesions were dark brown and contained brown pycnidia within and extending along lesion-free sections of the stems and basal portions of leaves. Diseased stems were cut into 3- to 5-mm pieces and disinfested in 70% ethyl alcohol. After drying, stem pieces were placed into petri dishes on the surface of potato glucose agar. Numerous, dark, immersed erumpent pycnidia with a single ostiole were observed in all lesions after 2 to 3 days. Axenic cultures were sent to the Foreign Disease-Weed Science Research Unit, USDA, ARS, Ft. Detrick, MD for testing in quarantine. Conidiophores were simple, cylindrical, and 5 to 25 × 2 μm (mean 12 × 2 μm). Alpha conidia were biguttulate, one-celled, hyaline, nonseptate, ovoid, and 6.3 to 11.5 × 1.3 to 2.9 μm (mean 8.8 × 2.0 μm). Beta conidia were one-celled, filiform, hamate, hyaline, and 11.1 to 24.9 × 0.3 to 2.5 μm (mean 17.7 × 1.2 μm). The isolate was morphologically identified as a species of Phomopsis, the conidial state of Diaporthe (1). The teleomorph was not observed. A comparison with available sequences in GenBank using BLAST found 528 of 529 identities with the internal transcribed spacer (ITS) sequence of an authentic and vouchered Diaporthe eres Nitschke (GenBank DQ491514; BPI 748435; CBS 109767). Morphology is consistent with that of Phomopsis oblonga (Desm.) Traverso, the anamorph of D. eres (2). Healthy stems and leaves of 10 30-day-old plants of S. tragus were spray inoculated with an aqueous suspension of conidia (1.0 × 106 alpha conidia/ml plus 0.1% v/v polysorbate 20) harvested from 14-day-old cultures grown on 20% V8 juice agar. Another 10 control plants were sprayed with water and surfactant without conidia. Plants were placed in an environmental chamber at 100% humidity (rh) for 16 h with no lighting at 25°C. After approximately 24 h, plants were transferred to a greenhouse at 20 to 25°C, 30 to 50% rh, and natural light. Stem lesions developed on three inoculated plants after 14 days and another three plants after 21 days. After 70 days, all inoculated plants were diseased, four were dead, and three had more than 75% diseased tissue. No symptoms occurred on control plants. The Phomopsis state was recovered from all diseased plants. This isolate of D. eres is a potential biological control agent of S. tragus in the United States. A voucher specimen has been deposited with the U.S. National Fungus Collections (BPI 878717). Nucleotide sequences for the ribosomal ITS regions (ITS 1 and 2) were deposited in GenBank (Accession No. EU805539). To our knowledge, this is the first report of stem canker on S. tragus caused by D. eres. References: (1) B. C. Sutton. Page 569 in: The Coelomycetes. CMI, Kew, Surrey, UK, 1980. (2) L. E. Wehmeyer. The Genus Diaporthe Nitschke and its Segregates. University of Michigan Press, Ann Arbor, 1933.

scholarly journals First Report of an Ovary Smut of Italian Thistle Caused by a Microbotryum sp. in Greece

Plant Disease ◽  
2006 ◽  
Vol 90 (5) ◽  
pp. 681-681 ◽  
Author(s):  
D. K. Berner ◽  
M. B. McMahon ◽  
J. Kashefi ◽  
E. Erbe
Keyword(s):  
United States ◽  
Biological Control ◽  
Biological Control Agent ◽  
Science Research ◽  
The United States ◽  
Internal Transcribed Spacers ◽  
Smut Fungi ◽  
Invasive Weed ◽  
Voucher Specimen ◽  
First Report

Italian thistle (Carduus pycnocephalus L.), family Asteraceae, is a common weed in Greece. It is also a problematic invasive weed in the western United States and a target of biological control efforts. In May 2005, smutted capitula of Italian thistle were found in an abandoned field in Halkiades, Greece. A total of 38 smutted plants, representing approximately 20% of those plants present, were found in a portion of the field that was lightly infested with Italian thistle. In most cases, capitula of all diseased flowers were smutted. In one or two cases, capitula on some branches of the plants were smutted, whereas capitula on other branches were healthy. Diseased capitula were noticeably more globose than healthy ovoid capitula, and diseased capitula did not open completely. When diseased capitula were split open, the ovaries in all florets within the capitula were filled with powdery masses of smut teliospores. Diseased capitula were collected, air dried, and sent to the quarantine facility of the Foreign Disease-Weed Science Research Unit (FDWSRU), USDA/ARS, Fort Detrick, MD. Teliospores within the capitula were extracted and observed microscopically. Teliospores of isolate DB05-014 were relatively uniform in shape and size, globose, 12.0 to 17.3 × 12.3 to 18.0 μm (mean 14.5 × 15.1 μm), violet tinted pale to medium yellowish-brown; wall reticulate appearing as coarse, radiate wings on the spore margin, 5 to 7 polyangular meshes per spore diameter, muri, 0.7 to 2.0 μm high in optical median view appearing as gradually narrowing blunt spines, 0.5 to 1 μm wide at their basis; in scanning electron microscopy (SEM), the meshes were subpolygonal, wall and interspaces were finely verruculose. Teliospores were more globose and slightly smaller than the description of Microbotryum cardui (A. A. Fischer Waldh.) Vánky (2), but the mean sizes were within the described range. When compared with teliospores of M. cardui on C. acanthoides, the numbers of polyangular meshes per spore diameter were within the range of the description using SEM, but the muri were about one-half of the height of those described. Nucleotide sequences for the internal transcribed spacers (ITS 1 and 2) and 5.8S ribosomal region (GenBank Accession No. AY280460) were aligned with sequences of other smut fungi using the BLAST algorithm of the National Center for Biotechnology Information. The closest alignment of DB05-014 was with M. scorzonerae (590 of 627 bp identities or 94% with 2% gaps). No sequences of M. cardui were available for comparison, but only M. cardui has been reported on Carduus spp. (1,2). Another smut reported on a Carduus sp. is Thecaphora trailii (1). DB05-014 is a likely variant of M. cardui from a previously unknown host. Italian thistle is an annual plant that reproduces solely by seeds (achenes). Because of the lack of seed production on smutted plants and the systemic nature of the disease, this fungus has great potential as a biological control agent for Italian thistle in the United States. A voucher specimen has been deposited with the U.S. National Fungus Collections (BPI 871812). To our knowledge this is the first report of a Microbotryum sp. parasitizing C. pycnocephalus. References: (1) K. Vánky. European Smut Fungi. Gustav Fischer Verlag, Stuttgart, Germany, 1994. (2) K. Vánky and D. Berner. Mycotaxon 85:307, 2003.

Hamas and Civil Society in Gaza

2013 ◽  
Author(s):  
Sara Roy
Keyword(s):  
United States ◽  
Political Violence ◽  
West Bank ◽  
Gaza Strip ◽  
Social Institutions ◽  
The United States ◽  
Great Promise ◽  
Religious Congregations ◽  
Regional Dynamics ◽  
Second Intifada

Many in the United States and Israel believe that Hamas is nothing but a terrorist organization, and that its social sector serves merely to recruit new supporters for its violent agenda. Based on extensive fieldwork in the Gaza Strip and West Bank during the critical period of the Oslo peace process, this book shows how the social service activities sponsored by the Islamist group emphasized not political violence but rather community development and civic restoration. The book demonstrates how Islamic social institutions in Gaza and the West Bank advocated a moderate approach to change that valued order and stability, not disorder and instability; were less dogmatically Islamic than is often assumed; and served people who had a range of political outlooks and no history of acting collectively in support of radical Islam. These institutions attempted to create civic communities, not religious congregations. They reflected a deep commitment to stimulate a social, cultural, and moral renewal of the Muslim community, one couched not only—or even primarily—in religious terms. Vividly illustrating Hamas's unrecognized potential for moderation, accommodation, and change, the book also traces critical developments in Hamas' social and political sectors through the Second Intifada to today, and offers an assessment of the current, more adverse situation in the occupied territories. The Oslo period held great promise that has since been squandered. This book argues for more enlightened policies by the United States and Israel, ones that reflect Hamas' proven record of nonviolent community building. A new afterword discusses how Hamas has been affected by changing regional dynamics and by recent economic and political events in Gaza, including failed attempts at reconciliation with Fatah.

Planting native trees to restore riparian forests increases biotic resistance to non-native plant invasions

2021 ◽  
pp. 1-24
Author(s):  
Chad F. Hammer ◽  
John S. Gunn
Keyword(s):  
United States ◽  
Ecosystem Service ◽  
Invasive Plant ◽  
Biotic Resistance ◽  
The United States ◽  
Tree Regeneration ◽  
Tree Planting ◽  
Plant Colonization ◽  
Native Plant ◽  
Native Trees

Abstract Non-native invasive plant species are a major cause of ecosystem degradation and impairment of ecosystem service benefits in the United States. Forested riparian areas provide many ecosystem service benefits and are vital to maintaining water quality of streams and rivers. These systems are also vulnerable to natural disturbances and invasion by non-native plants. We assessed whether planting native trees on disturbed riparian sites may increase biotic resistance to invasive plant establishment in central Vermont in the northeastern United States. The density (stems/m2) of invasive stems was higher in non-planted sites (x̄=4.1 stems/m2) compared to planted sites (x̄=1.3 stems/m2). More than 90% of the invasive plants were Japanese knotweed (Fallopia japonica). There were no significant differences in total stem density of native vegetation between planted and non-planted sites. Other measured response variables such as native tree regeneration, species diversity, soil properties and soil function showed no significant differences or trends in the paired riparian study sites. The results of this case study indicate that tree planting in disturbed riparian forest areas may assist conservation efforts by minimizing the risk of invasive plant colonization.

Assessing the role of generalist predators in the biological control of alfalfa weevil (Coleoptera: Curculionidae)

2017 ◽  
Vol 149 (4) ◽  
pp. 525-533 ◽  
Author(s):  
Tatyana A. Rand
Keyword(s):  
United States ◽  
Biological Control ◽  
Experimental Work ◽  
United States Of America ◽  
Acyrthosiphon Pisum ◽  
The United States ◽  
Generalist Predators ◽  
Alfalfa Weevil ◽  
Exclusion Experiment ◽  
Predator Exclusion

AbstractAlfalfa weevil (Coleoptera:Curculionidae) is a major pest of alfalfa throughout the United States of America. Biological control research has disproportionately focussed on introduced parasitoids. Generalist predators may also be important, but experimental work evaluating their impacts is lacking. I combined a cross-site survey with a predator exclusion experiment to identify key predators, and test for impacts on weevil survival and plant defoliation levels in Montana and North Dakota, United States of America. Spiders (Araneae) dominated the complex, followed by Nabidae (Hemiptera) and Coccinellidae (Coleoptera). None of the dominant predators showed aggregative responses to weevil (Hypera postica (Gyllenhal); Coleoptera: Curculionidae) or pea aphid (Acyrthosiphon pisum (Harris); Hemiptera: Aphididae) densities across 10 sites surveyed. However, weevil densities were positively correlated with both coccinellid and nabid densities across transects at the experimental site. Thus, predator groups traditionally associated with aphids can show strong aggregative numerical responses to alfalfa weevil larvae at smaller scales. Predator exclusion revealed no significant predator effects on larval survival or alfalfa damage. However, final densities of pea aphids were significantly higher in exclusion treatments relative to controls. The results suggest that even under conditions where predators exert significant pressure on aphids, they may still have minimal impacts on weevils. Additional experimental work is necessary to determine the broader potential of generalist predators as alfalfa weevil control agents.

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