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United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Invasive species

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Potential Causes And Consequences Of Decreased Body Size In Field Populations Of Coccinella Novemnotata, John Losey, Jordan Perlman, James Kopco, Samuel Ramsey, Louis Hesler, Edward Evans, Leslie Allee, Rebecca Smyth Jan 2012

Potential Causes And Consequences Of Decreased Body Size In Field Populations Of Coccinella Novemnotata, John Losey, Jordan Perlman, James Kopco, Samuel Ramsey, Louis Hesler, Edward Evans, Leslie Allee, Rebecca Smyth

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Coccinella novemnotata, the nine-spotted lady beetle, was historically one of the most common lady beetles across the US and southern Canada. In the 1980s it became extremely rare and has remained rare. In 2008 adult C. novemnotata were collected from field populations in Oregon and South Dakota and initial observations suggested that these individuals seemed smaller than the mean size of the species historically. These observations led to a series of experiments to determine if there had been significant decrease in size and if any decrease found was due to a genetic change or to environmental factors. In the …


Classical Biological Control For The Protection Of Natural Ecosystems, R.G. Van Driesche, R I. Carruthers, T. Center, M.S. Hoddle, J. Hough-Goldstein, L. Morin, L. Smith, D.L. Wagner, B. Blossey, V. Brancatini, R. Casagrande, C.E. Causton, J.A. Coetzee, J. Cuda, J. Ding, S.V. Fowler, J. H. Frank, R. Fuester, J. A. Goolsby, M. Grodowitz, T.A. Heard, M.P. Hill, J.H. Hoffmann, J. Huber, M. Julien, M.T.K. Kairo, M. Kenis, P. Mason, J. Medal, R. Messing, R. Miller, A. Moore, P. Neuenschwander, R. Newman, H. Norambuena, W.A. Palmer, R. Pemberton, A. Perez-Panduro, P.D. Pratt, M. Rayamajhi, S. Salom, D. Sands, S. Schooler, M. Schwarzländer, A. Sheppard, R. Shaw, P.W. Tipping, R.D. Van Klinken Jan 2010

Classical Biological Control For The Protection Of Natural Ecosystems, R.G. Van Driesche, R I. Carruthers, T. Center, M.S. Hoddle, J. Hough-Goldstein, L. Morin, L. Smith, D.L. Wagner, B. Blossey, V. Brancatini, R. Casagrande, C.E. Causton, J.A. Coetzee, J. Cuda, J. Ding, S.V. Fowler, J. H. Frank, R. Fuester, J. A. Goolsby, M. Grodowitz, T.A. Heard, M.P. Hill, J.H. Hoffmann, J. Huber, M. Julien, M.T.K. Kairo, M. Kenis, P. Mason, J. Medal, R. Messing, R. Miller, A. Moore, P. Neuenschwander, R. Newman, H. Norambuena, W.A. Palmer, R. Pemberton, A. Perez-Panduro, P.D. Pratt, M. Rayamajhi, S. Salom, D. Sands, S. Schooler, M. Schwarzländer, A. Sheppard, R. Shaw, P.W. Tipping, R.D. Van Klinken

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Of the 70 cases of classical biological control for the protection of nature found in our review, there were fewer projects against insect targets (21) than against invasive plants (49), in part, because many insect biological control projects were carried out against agricultural pests, while nearly all projects against plants targeted invasive plants in natural ecosystems. Of 21 insect projects, 81% (17) provided benefits to protection of biodiversity, while 48% (10) protected products harvested from natural systems, and 5% (1) preserved ecosystem services, with many projects contributing to more than one goal. In contrast, of the 49 projects against invasive …


Biodiversity Maintenance Mechanisms Differ Between Native And Novel Exotic-Dominated Communities, Brian J. Wilsey, Terri B. Teaschner, Pedram P. Daneshgar, Forest I. Isbell, H. Wayne Polley Jan 2009

Biodiversity Maintenance Mechanisms Differ Between Native And Novel Exotic-Dominated Communities, Brian J. Wilsey, Terri B. Teaschner, Pedram P. Daneshgar, Forest I. Isbell, H. Wayne Polley

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

In many systems, native communities are being replaced by novel exotic-dominated ones. We experimentally compared species diversity decline between nine-species grassland communities under field conditions to test whether diversity maintenance mechanisms differed between communities containing all exotic or all native species using a pool of 40 species. Aboveground biomass was greater in exotic than native plots, and this difference was larger in mixtures than in monocultures. Species diversity declined more in exotic than native communities and declines were explained by different mechanisms. In exotic communities, overyielding species had high biomass in monoculture and diversity declined linearly as this selection effect …


Androthrips Ramachandrai (Thysanoptera: Phlaeothripidae): An Introduced Thrips In The United States, David W. Boyd, Jr., David W. Held Jan 2006

Androthrips Ramachandrai (Thysanoptera: Phlaeothripidae): An Introduced Thrips In The United States, David W. Boyd, Jr., David W. Held

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Androthrips ramachandrai Karny is an exotic thrips, assumed to be predacious, and is associated with gall-inducing thrips. It was first reported in the U.S. from FL, and intercepted in CA from Thailand in 2002. We surveyed Ficus spp. with Gynaikothrips-induced galls in AL, CA, FL, HI, LA, MS, and TX, and document that A. ramachandrai is now established in CA, FL, HI, and TX. It probably has been spread by the ornamental horticulture industry. We outline its biology and compare it to a congener A. flavipes, a documented thrips predator. Androthrips ramachandrai has the potential to be a …


Movements Of European Starlings Captured At A Winter Roost In Omaha, Nebraska, H. Jeffrey Homan, George M. Linz, Garrett W. Unrein, James R. Thiele, John M. Hobbs Jan 2006

Movements Of European Starlings Captured At A Winter Roost In Omaha, Nebraska, H. Jeffrey Homan, George M. Linz, Garrett W. Unrein, James R. Thiele, John M. Hobbs

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

European starlings (Sturnus vulgaris) were using downtown Omaha, Nebraska, as a winter roosting site. We used radio telemetry and leg streamers to track birds in this roost. Between late December 2005 and March 2006, we radio tagged 57 starlings and located them 432 times. We attached leg bands and colored leg streamers to over 1,300 starlings captured at trapping sites within 7 km (4 mi) of the downtown roost. These techniques yielded data on previously unknown sites where starlings gathered to forage, stage, and roost. The maximum distance that a marked bird was observed from the downtown roost …


Aboveground Productivity And Root–Shoot Allocation Diver Between Native And Introduced Grass Species, Brian J. Wilsey, H. Wayne Polley Jan 2006

Aboveground Productivity And Root–Shoot Allocation Diver Between Native And Introduced Grass Species, Brian J. Wilsey, H. Wayne Polley

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Plant species in grasslands are often separated into groups (C4 and C3 grasses, and forbs) with presumed links to ecosystem functioning. Each of these in turn can be separated into native and introduced (i.e., exotic) species. Although numerous studies have compared plant traits between the traditional groups of grasses and forbs, fewer have compared native versus introduced species. Introduced grass species, which were often introduced to prevent erosion or to improve grazing opportunities, have become common or even dominant species in grasslands. By virtue of their abundances, introduced species may alter ecosystems if they differ from natives in …


Herbivory Alters Resource Allocation And Compensation In The Invasive Tree Melaleuca Quinquenervia, P. D. Pratt, M. B. Rayamajhi, T. K. Van, T. D. Center, P. W. Tipping Jan 2005

Herbivory Alters Resource Allocation And Compensation In The Invasive Tree Melaleuca Quinquenervia, P. D. Pratt, M. B. Rayamajhi, T. K. Van, T. D. Center, P. W. Tipping

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The Australian native Melaleuca quinquenervia is highly invasive in the Florida Everglades, U.S.A., where it experiences limited competition or herbivory from native species, making it a likely candidate for compensation. The introduced biological control agent Oxyops vitiosa feeds exclusively on the seasonal flushes of developing foliage at branch apices, which represents ~ 15% of the total foliar biomass.


Somatic Mutation-Mediated Evolution Of Herbicide Resistance In The Nonindigenous Invasive Plant Hydrilla (Hydrilla Verticillata) And Franck E. Dayan, Albrecht Michel, R. S. Arias, Brian E. Scheffler, Stephen O. Duke, Michael Netherland, Franck E. Dayan Jan 2004

Somatic Mutation-Mediated Evolution Of Herbicide Resistance In The Nonindigenous Invasive Plant Hydrilla (Hydrilla Verticillata) And Franck E. Dayan, Albrecht Michel, R. S. Arias, Brian E. Scheffler, Stephen O. Duke, Michael Netherland, Franck E. Dayan

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Hydrilla (Hydrilla verticillata L.f. Royle) was introduced to the surface water of Florida in the 1950s and is today one of the most serious aquatic weed problems in the USA. As a result of concerns associated with the applications of pesticides to aquatic systems, fluridone is the only USEPA-approved chemical that provides systemic control of hydrilla. After a decrease in fluridone’s efficacy at controlling hydrilla, 200 Florida water bodies were sampled to determine the extent of the problem and the biological basis for the reduced efficacy. Our studies revealed that hydrilla phenotypes with two- to six-fold higher fluridone resistance …