Vacant niches, behavioral constancy and the spread of Nearctic Chymomyza amoena (Loew) (Diptera: Drosophilidae) in Europe: Evidence from overwintering studies.

H. T. Band (1), R. Neal Band (1) and G. Bächli (2)
1-Zoology Dept., Michigan State University, East Lansing, MI 48824; 2-Zoological Museum, Winterthurerstrasse 190, University of Zürich-Irchel, CH-8057 Zürich, Switzerland.

Nearctic Chymomyza amoena is the only drosophilid to breed in fallen parasitized substrates (plums, unripe and ripe apples, crabapples, acorns, black walnut hulls). Minimum generation time is 30 days. The breeding season extends from May into October. The species is coldhardy; 3 rd instar larvae overwinter in fruits or nuts. Chymomyza amoena was discovered in the former Czechoslovakia in 1975, spread rapidly, entered Switzerland in 1988 and was reared from parasitized chestnuts, acorns and soft fruits in 1990/1991 in Canton Ticino. Later work in Switzerland showed C. amoena still bred in parasitized apples in addition to chestnuts and acorns. We predicted and verified it moved north into cider apple orchards on the Swiss/German border and south into northern Italy, also from Vienna into southern Austria and in France from Jura, Ain, Rhone and Is P re into the Ardeche region. Pest larvae exit chestnuts in autumn; C. amoena may use them into July, then breeds in apples. We investigated overwintering in chestnuts in March 2004 in southern Switzerland, northern Italy and the Ardeche and in acorns in southern Switzerland. Parasitized chestnuts were empty; C. amoena larvae were in acorns along with Cydia splendana caterpillars. Europe’s hot summer in 2003 delayed chestnut drop but adds evidence this represents a vacant niche for C. amoena. Breeding in parasitized acorns and apples may account for C. amoena’s spread in Germany and throughout Europe.

Invasion genetics of emerald ash borer (Agrilus planipennis Fairmaire) in North America

Alicia M. Bray (1), Robert A. Haack (2), Leah S. Bauer (2), Therese Poland (2), James J. Smith (1,3,4)
1-MSU Department of Entomology, 2-USDA Forest Service, North Central Research Station, 3-MSU Department of Zoology, 4-MSU Lyman Briggs School of Science

Emerald ash borer (EAB) was first detected in Michigan and Canada in 2002. We have been using mtDNA gene sequencing and analysis of amplified fragment length polymorphisms (AFLPs) to assess the genetic structure of EAB populations and to estimate the geographic origin(s) of the North America’s EAB populations. These analyses will help us to understand the invasion dynamics of EAB and to identify geographic localities of potential biocontrol agents.

Mitochondrial cytochrome oxidase I (COI) sequences (485 bp) of EAB from North American, China, and six EAB individuals from three localities in South Korea, were identical. However, we also observed five unique COI sequences from individuals in two populations in South Korea that differed from the common sequence by 2-4 nucleotides. In addition, a single EAB from Japan differed from the common sequence by 22 nucleotide changes (3.7%). AFLP profiles obtained from these same EAB individuals, using four selective AFLP primer pairs, revealed differences both within populations from the same location as well as between all populations. Neighbor-joining analysis of the 139-band AFLP data set showed that EAB individuals from MI cluster more often with individuals from China than they do with EAB from South Korea. However, South Korea cannot be ruled out as the origin of North American EAB since the common mtDNA sequence that is shared by all Chinese and North American EAB, exists in South Korean populations. Increased Asian sampling and additional molecular genetic data will be necessary to elucidate the geographic origin(s) of North American EAB.

U.S. metropolitan areas as hubs of human-mediated pathways of non-indigenous species.

Manuel Colunga-Garcia (1,4), Robert Haack (2), Soji Adelaja (3), Stuart Gage (1), Jiaquo Qi (4), Roger Magarey (5) .
1-MSU/Entomology/Computational Ecology and Visualization Laboratory, 2-USDA/Forest Service, 3-MSU/Land Policy Institute,
4-MSU/Center for Global Change and Earth Observations, 5-USDA/APHIS/PPQ/Center for Plant Health Science and Technology.

U.S. Metropolitan areas are vulnerable to biological invasions and also act as pathway hubs of invasive species in agricultural and forested lands. Two characteristics exist that determine the vulnerability of metropolitan areas: the amount of international transport that passes through them and the ecological composition of their landscape. Analysis of transport pathways for all metropolitan areas will permit us to identify those that have the highest vulnerability to invasive species and require focused risk management strategies. To analyze all pathways for the 369 metropolitan areas requires an information system that can access trade, eco-climatic, phytosanitary, and pest distribution data. However, the required information infrastructure needed to conduct such nation-wide analysis of transport pathways does not exist. To address this challenge we will develop a Trade Eco-climate Phytosanitary Pest distribution System (TEPPDS) to identify “hot zones” in the U.S. where metropolitan areas are at risk of invasion by non-indigenous species via any of all the commodities/pathways.

Evans, J.A. , D.A. Landis, and D.W. Schemske.
Michigan State University, East Lansing, MI.

The influence of species diversity on community invasibility is variably argued to be positive, neutral, or negative. In eight temperate deciduous forests in Southern Michigan that have been invaded by exotic plant species, we found a positive correlation between site native species richness and site exotic species richness. However, the relationship between exotic plant abundance and species richness within sites changed predictably from positive at species poor sites to negative at species rich sites, implying that different mechanisms are responsible for either promoting or resisting invasions in different communities. We propose that environmental stress tolerance may contribute to limiting invasions in species poor assemblages, whereas competitive interactions are more likely to limit invasions in species rich communities. This suggests that neither biotic resistance nor 'the rich get richer' hypothesis satisfactorily explains patterns of invasibility. Rather, both serve as endpoints along a continuous gradient of resource competition and environmental stress tolerance.

Landscape structure impacts soybean aphid biological control.

Mary Gardiner (1), Nick Schmidt (2), Emily Mueller (3), Jeremy Chacon (4), Doug Landis (1), Matt O’Neal (2), Chris Difonzo (1), George Heimpel (4), Claudio Gratton (3), and Mike Brewer (1).
1-204 CIPS, Michigan State University, East Lansing, MI 48824, 2-117 Insectary, Iowa State University, Ames, IA 50011, 3-237 Russell Lab, 1630 Linden Dr. Madison, WI 53706, 4-219 Hodson Hall, 1980 Folwell Ave. University of Minnesota, St. Paul, MN 55108.

The soybean aphid, Aphis glycines Matsumura, a native of Asia, was first detected in the US in 2000. Its current distribution extends throughout the North-Central US and into Canada. Within this introduced range landscape structure has critical influences on soybean aphid, its natural enemies, and their interactions in agroecosystems. The impact of the natural enemy community on soybean aphid population dynamics varied across 12 sites sampled in Michigan, Wisconsin, Minnesota and Iowa. In 4 of the 12 sites, predators had no impact on aphid population growth. In the remaining 8 sites, predators either delayed (4 sites) or prevented aphid populations from reaching threshold (4 sites). We examined the relationship between lady beetle species and the amount of non-crop habitat (woodlots, wetlands, pasturelands, grasslands, and urban areas) and soybean in the landscape as well as overall landscape heterogeneity. Exotic lady beetle species (Harmonia axyridis, Hippodamia variegata, and Coccinella septempunctata) were positively correlated with non-crop habitat and habitat heterogeneity. Native lady beetle populations (Hippodamia convergens, Coleomegilla maculata, Cycloneda munda, Hippodamia parenthesis) were negative correlated with habitat heterogeneity; they were most abundant in homogeneous landscapes dominated by corn and soybean. These findings suggest that native and non-native natural enemies of soybean aphid may be experiencing landscape influences in different ways.

Does non-cropped habitat near soybean fields affect the recruitment of parasitoids to soybean aphid (Aphis glycines)?

Langley, Shaun A., Takuji Noma, Michael Brewer

Soybean aphids, Aphis glycines, are important agricultural pests of soybean production. Soybean aphids were first discovered in the United States in 2000 by researchers in Wisconsin, and have since dispersed through much of the Midwest. Due to their high population densities, soybean aphids can cause significant damage to soybean production, up to a 40% reduction in yields. Yet, the growth rates of soybean aphid populations can be limited by the extant natural enemy community. Seven species of parasitoids are known to attack soybean aphids, including a newly discovered species, Binodoxys sp., endemic to the Midwest. Our study explores the relative importance of non-cropped habitat on the edge of soybean fields on the recruitment of parasitoids to soybean aphid. Edge habitats were manipulated under several mowing regimes to achieve varying degrees of plant diversity. Soybean aphids placed on sentinel plants at varying distances, from field edge into soybean and grass, showed varying recruitment of parasitoids. This paper explores how spatial patterns affect the response of two endemic parasitoids, Lysiphlebus testaceipes and Binodoxys sp. to the presence of soybean aphid on the landscape.

The regional introduction of invasive plant species in the state of Michigan

Virginia Patterson

Dates and locations of all the herbarium records were recorded for 13 of the most highly invasive plant species in the state of Michigan. Data from herbarium specimens were gathered from the Michigan State University Herbarium and Cranbrook Institute of Sciences. Herbaria were compiled from recorded information at the University of Michigan. The state of Michigan was divided into seven different locations based on broad similarities in climate, vegetation, land use, and development. The initial occurrences of each species were analyzed to compile a representation of where in the state of Michigan the invasive species had a tendency to be introduced. The data showed that the nine species of the 13 were first reported from Southeastern Michigan. Southwestern Michigan had the second highest number with 2 initial occurrences. Eleven of 13 initial occurrences happened in either southeastern or southwestern Michigan. The disproportionately large amount of first initial occurrences in these regions suggests that Michigan invasive species were introduced from the southern border of the Lower Peninsula and a test of significance that accounts for differences in regional collecting showed that invasive species were significantly more likely to be introduced in Southeastern Michigan.

Interspecific variation in ash resistance to emerald ash borer

Lead author: Eric Rebek (1) Co-authors: Daniel Herms (2), David Smitley (1), Pierluigi Bonello (3), and Don Cipollini (4)
1-Department of Entomology, Michigan State University, East Lansing, MI 48824, 2-Department of Entomology, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster, OH 44691, 3-Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, 4-Department of Biological Sciences, Wright State University, Dayton, OH 45435

Outbreaks of emerald ash borer (EAB) in its native range of Asia appear to be rare and isolated, colonizing only stressed trees. Thus, endemic populations of EAB behave much like native buprestids in North America, implying that Asian ashes may be generally resistant with weakened trees being preferentially colonized. Native trees may be more resistant to native herbivores due to the development of plant defenses over their co-evolutionary history. This hypothesis is supported by a 20-year study at Ohio State University study of birch resistance that found North American where birches native t o North America were found were highly resistant to native bronze birch borer, which is also endemic to North America, while European and Asian birches were extremely susceptible. To test the hypothesis further, we established a replicated common garden planting of North American and Asian ashes in Novi, Michigan, an area supporting dense populations of EAB. We compared resistance to EAB among six horticultural cultivars of North American and Asian ash cultivars as expressed by density of EAB exit holes and EAB-induced dieback and mortality. After two years, Manchurian ash (Fraxinus mandshurica), which co-evolved with EAB in Asia, had lowe r st lowest densities of exit holes and lowest levels of dieback and mortality than relative to white (F. americana) and green ash (F. pennsylvanica) cultivars, as well as a North American/Asian hybrid. These preliminary results are consistent with the hypothesis that Manchurian ash is a source of resistance genes to EAB by virtue of their shared co-evolutionary history. Current research objectives include characterizing is focused on comparing resistance of among an expanded set of North American, Asian, and European ashes species/cultivars , identifying phytochemical mechanisms of resistance in Manchurian ash, and determining how environmental stress the affect s of ash plant stress in resistance to EAB.

Zebra mussels (Dreissena polymorpha) decrease macrozooplankton biomass in inland Michigan lakes

Carrie E. H. Scheele (1), Lesley B. Knoll (2, 3) and Donald J. Hall (1)
1-Department of Zoology, Michigan State University, 2-Department of Fisheries and Wildlife, Michigan State University, 3-Current Address: Department of Zoology, Miami University

The zebra mussel (Dreissena polymorpha), has drastically transformed large freshwater ecosystems since its invasion of the Laurentian Great Lakes in 1988. Zebra mussels are now invading small inland lakes, but little is known about their effects on these systems. We conducted an extensive survey of inland Michigan warm-water lakes to examine the indirect impacts of zebra mussels on macrozooplankton biomass. Sixty lakes with similar morphometries and nutrient concentrations were sampled in 2002-2003. Thirty lakes were infested with zebra mussels (invaded), and 30 lakes were zebra mussel free (uninvaded). Preliminary analyses indicate zebra mussels lowered chlorophyll a by 30%, and light extinction coefficients by 17%, thus significantly increasing the water clarity of invaded lakes. Total macrozooplankton biomass decreased by 44%, cladoceran biomass decreased by 48%, and Daphnia galeata, a favorite prey item of planktivorous fish, declined in biomass by 52%. These results suggest that zebra mussels have a bottom-up effect on inland lake ecosystems, and this effect may be observed in higher trophic levels. Understanding how zebra mussels affect macrozooplankton will help identify potential mechanisms by which fish are influenced by this invader.

Genetic and environmental effects on larval sea lamprey size and growth

Kim Scribner (1,2), Michael Jones (1), Guilherme Rosa (1,3)
Michigan State University. 1 Department of Fisheries and Wildlife, 2 Department of Zoology, 3 Department of Animal Science

Control of non-native sea lamprey represents one of the largest fishery management issues in the Great Lakes. Recent management efforts have been directed at developing alternative control methods that disrupt lamprey reproduction. The efficacy of these methods is based on assumptions pertaining to fundamental, as yet unresolved aspects of the species breeding behavior, reproductive success, and patterns of larval dispersal, growth, and survival. We used replicated experimental streams stocked with small numbers of adult males and females together with microsatellite loci for genetic determination of parentage, to elucidate important aspects of the sea lamprey behavior and early juvenile life history. Reproductive success of male and female lamprey was highly variable. High rates of polyandry and polygyny were observed, and we documented high variances in male and female reproductive success. Full and half sibs were typically found in close proximity in the stream, though larval dispersal distances >5 km were observed. Estimates of heritability for larval body weight and length were 0.458 and 0.443, respectively across streams. We discuss the implications of additive genetic covariance between relatives and stream environmental heterogeneity to recruitment dynamics and compensatory demographic responses to current and proposed sea lamprey control strategies.

Behavioral interactions of the mottled sculpin (Cottus bairdi) with the invasive round goby (Neogobius melanostomus) in nearshore areas of the Laurentian Great Lakes

Janice Sloan and Reuben Goforth
Michigan State University, East Lansing, MI

Mottled sculpin (Cottus bairdi) of western Lake Michigan nearshore waters are diminishing in the wake of invasions by the round goby (Neogobius melanostomus). This decrease is of great concern because we have a limited understanding of the potential impacts that the loss of this species will have on the Great Lakes ecosystem as a whole. Anecdotal observations suggest that the recent proliferation of Cladophora, a filamentous green alga, may interfere with the spread of the round goby. In areas affected by the Cladophora, mottled sculpin populations appear to be stable, although round gobies do not appear to be as prevalent in these areas compared to Great Lakes nearshore areas without Cladophora. I seek to better understand how Cladophora may stem the invasion of the round goby and influence mottled sculpin populations, specifically with respect to how may change feeding behavior in both species. To evaluate this relationship, I will use an experimental design that focuses on feeding behavior, feeding efficiency, habitat preferences, and responses to invading fish. The results of this study will be highly relevant to the conservation of the Great Lakes mottled sculpin and the management of the invasive round goby providing an increased understanding of the relationships that exist among mottled sculpins, round gobies, and Cladophora in the nearshore areas.

Public awareness & rapid response planning: Michigans experience with heading off hydrilla

Carol Swinehart (1) and Emily Finnell (2)
1-Michigan Sea Grant, 2-Michigan Office of the Great Lakes

Hydrilla verticillata is an invasive aquatic plant that has caused significant ecological disturbance and great economic cost in the southern United States. In early 2004, Michigan’s Aquatic Nuisance Species Council became aware that a variety of the plant is able to survive in northern latitudes and has already become established in locations as far north as Maine and close as Pennsylvania. The council appointed a task force to develop plans for increasing public awareness of the species in Michigan and to prepare a rapid response plan for addressing the problem if it is found in the state.  Michigan Sea Grant and the Michigan Office of the Great Lakes led a public awareness campaign in 2004, employing a fact sheet, Hydrilla Hunt postcard mailer and a strategic mix of other media. The task force drafted a rapid response plan, based on a model developed the Great Lakes Aquatic Nuisance Species Panel. This presentation will describe the methods and outcomes of the public awareness campaign and review the significant elements of the rapid response plan.

From aquariums to zebra mussels: working with stakeholders to solve aquatic invasive species problems

Carol Swinehart
Michigan Sea Grant

Michigan has been known for many years as the “water wonderland”, but developments in recent years have made it seems that the state is more like Alice’s wonderland of strange creatures doing unpredictable things. Whether it’s industries and municipalities spending millions of dollars annually to rid their intake pipes of zebra mussels, or wetland managers watching their resources turn purple with a garden flower run amok, or baitfish harvesters accused of introducing invasive fishes into the state’s waterways, Sea Grant has worked with many different groups over the past 15 years to recognize, research and develop appropriate strategies to prevent the introduction of and manage the ever increasing menagerie of uninvited and misbehaving creatures. This presentation will highlight several stakeholder types and solutions Sea Grant has developed to address their concerns.

Dr. John C. Taylor and Mr. James L. Roach
December 6, 2005

The principal conclusion of this study is that a cessation of ocean shipping on the Great Lakes would result in a transportation cost penalty of US$54.9 million per year.  The study has been peer reviewed by a panel of four peer reviewers from the agricultural economics and economics professions who concluded that the study methodology and conclusions are reasonable.  The relatively small transportation cost penalty of US$54.9 million is due to the fact that just 12.3 million metric tons of ocean vessel cargo passed into and out of the Lakes via the MLO Section of the St. Lawrence Seaway in 2002, or some 6.8% of total Great Lakes -St. Lawrence Seaway System tonnage.  It is also due to the fact that the costs of the alternative modes, for lakers, rail and barge primarily, are not substantially higher than the cost for the ocean direct routings into and out of Great Lakes ports.  While these other modes have some potential capacity constraints, we believe laker and rail capacity would be able to accommodate the extra volume.   Overall, the conclusion is that ocean vessels on the Lakes make only a modest contribution to transportation cost savings for users of the System.  The calculated cost penalty represents a 5.9% increase in the current door to door transportation cost for the goods currently moving via ocean shipping in the Great Lakes.  The study findings are highly relevant to the growing debate over whether or not ocean ships in the Lakes provide sufficient benefits to society, given the much larger biological science researcher estimates of the costs of ocean borne invasive species.  These scientist's estimates of the costs of existing invasives range from $200 million to as high as $5 billion per year.

Policy Design and Economic Impact Analysis for Managing Invasive Species Risk

Suzanne Thornsbury and Lili Gao
Michigan State University, East Lansing, MI

International trade is a critical vector in the potential spread of invasive species. In designing policies, regulators face a challenge to not be overly lax about pest risks or overly restrictive of trade. Systems approach policies are multi-step sanitary and phytosanitary regulations where at least two steps are designed in such a way to have independent effects on reducing associated pest risks. Too few measures included to reduce risk will fail to protect the natural environment or domestic commercial agriculture from invasive species damages resulting in potential net negative economic impacts of trade. Conversely, too many measures in a systems approach raises costs and may restrict trade unnecessarily, with net economic losses. China is the largest apple producing country in the world and has recently asked for consideration to export fresh apples to the U.S. The potential for trade presents both opportunities and challenges for U.S. horticultural industries, natural environment, and national welfare. In this paper, we will first extrapolate a potential U.S. “Systems Approach” for Chinese fresh apples. By quantitatively comparing existing policies with like-products, we identify most likely pests associated with Chinese apples, and phytosanitary measures to manage these pests. Using this case as an example, we show how a partial equilibrium model can be used to link invasive species risk and economic assessment. Results provide critical information for policymakers seeking to manage the threat of invasive species spread while not unnecessarily constraining product trade.