I. David Andow, 219 Hodson Hall, 1980 Folwell Ave., University of Minnesota, St. Paul, MN 55108, Phone: (612) 624-5323, FAX: (612) 625-5299, E-mail: dandow@tc.umn.edu

Project Title: Parasitoid foraging for intermittently concealed hosts.

Investigators: Jennifer White and David Andow, Dept. Entomology, University of Minnesota

Contact: Jennifer White (whit0079@umn.edu)

Project description: Many insect herbivores feed in concealed locations and thus limit their susceptibility to foraging natural enemies. However, some herbivores move into and out of concealment many times over the course of their development, creating windows of greater vulnerability to attack. Parasitoids that specialize on such hosts face an interesting foraging decision: having located an inaccessible host, how long should the parasitoid wait for the host to become accessible? We explored this question with a simple foraging model, and found that parasitoids should take one of two strategies, depending on three parameters. Parasitoids should leave immediately upon discovering a host is inaccessible if 1) the probability of locating another host is high, 2) the proportion of hosts that are accessible at any point in time is high, and 3) the probability that an inaccessible host will emerge from hiding is low. Conversely, the parasitoid should wait indefinitely for hosts to emerge from concealment when the opposite conditions hold. We then estimated these parameter values for the European corn borer, Ostrinia nubilalis, and its specialist parasitoid, Macrocentrus grandii. From these values, we predicted that the optimal strategy for M. grandii should vary with host density, with a leaving strategy favored by high host density, and a staying strategy by low host density. These results suggest that individual parasitoid foraging experience and learning should play an important role in the foraging behavior expressed by M. grandii.

Biological Control Publications since 2002 – Andow lab

Andow, D.A. and D.M. Olson. 2003. Inheritance of host finding ability on structurally complex surfaces. Oecologia 136: 324-328.
Harmon, J. P. 2003. Indirect interactions among a generalist predator and its multiple foods. Ph.D. University of Minnesota, Ph.D. Thesis, St. Paul, MN.
Harmon, J. & D.A. Andow. 2003. Alternative foods as a mechanism to enhance a generalist ladybird's predation of target prey. Proceedings of the 1st International Symposium on Biological Control of Arthropods. Honolulu, Hawaii, 1/2002. Pp. 244 – 249.
Harmon, J.P., E.E. Hladilek, J.L. Hinton, T.J. Stodola and D.A. Andow. 2003. Herbivore response to vegetational diversity: Spatial interaction of resources and natural enemies. Population Ecology 45: 75-81.
Hladilek, E. Bottom-up limitation in a detrital food web: Effects of resource availability on ground beetles (Coleoptera, Carabidae). M.S. Thesis, St. Paul, MN.
Olson, D.M. & D.A. Andow. 2002. Inheritance of an oviposition behavior by an egg parasitoid. Heredity 88: 437-443.
White, J.A. & D.A. Andow. 2003. Natural enemies and resistance management in Bt corn: Parasitoid searching behavior and host spatial distribution. Proceedings of the 1st International Symposium on Biological Control of Arthropods. Honolulu, Hawaii, 1/2002. Pp. 292.

Back to top of web page

II. Mark Ascerno, 219 Hodson Hall, 1980 Folwell Ave., University of Minnesota, St. Paul, MN 55108, Phone: (612) 624-3278, FAX: (612) 625-5299, E-mail: m-asce@maroon.tc.umn.edu

Project title: Integrated pest management of fungus gnats Bradysia spp. in commercial greenhouses/ Phase II.

Investigators: Mark E. Ascerno and Michael J. McDonough, Department of Entomology, University of Minnesota.

Contact: Mark E. Ascerno (mascerno@umn.edu)

Project Description: Develop greenhouse IPM practices for fungus gnats, principally the sciarid species Bradysia coprophila (Lintner) and Bradysia impatiens (Johannsen).

We investigated host susceptibility to fungus gnat injury in three ornamental crops: New Guinea Impatiens, poinsettias, and zonal geraniums under commercial grower conditions. Unrooted cuttings were planted in three types of growing media, two commonly used foam products and soilless media. The stuck cuttings were placed in Plexiglas/screened enclosures and grown under periodic misting and bottom heating to promote rooting. Fungus gnat adults were released 4 times into each enclosure. At the end of 5 weeks the plugs were dismantled and the roots were examined for root quality and plant death. Poinsettia was the most susceptible host with the poorest root quality and highest plant mortality. New Guinea Impatiens had better root quality and less plant mortality. The zonal geraniums were the least susceptible host, showing little root injury and no mortality. Root quality was higher in the foam products than in soilless media.

We continued our investigation into the use of attractant disks to monitor fungus gnat larvae populations but the experiments were terminated due to the appearance of a predatory rove beetle Atheta spp. (Coleoptera: Staphylinidae). BioBest Biological Systems is marketing Atheta coriaria as a beneficial for use in commercial greenhouses. Our observation is that Atheta spp. has too great a reproductive lag to prevent both direct and indirect damage by fungus gnats. In addition, the Atheta adult is slightly larger than an adult fungus gnat and we expect its presence on ornamentals to be unacceptable to consumers.
A pesticide/biological control efficacy experiment with rooted poinsettia cuttings was conducted comparing 3 commonly used chemical pesticides, three biological control agents, and the combination of PlantShield? (a fungal rhizosphere mutualist and antagonist against fungal pathogens), and NemaShield.? The three pesticides were (Distance?, DuraGuard?, and Marathon?). Theses biological control agents were Azatin? (azadirachtin), Gnatrol (Bacillus thuringiensis israelensis) and NemaShield (the Steinernema feltiae nematode). The experiment was conducted with two media mixes. After transplanting, the pots were arranged in Plexiglas/screen enclosures arranged in randomized blocks. Each Plexiglas/screen enclosure was inoculated with 25 adult fungus gnats weekly for the duration of the experiment. Larval counts were monitored and recorded weekly. Plant height and root/shoot dry weights data were collected. Both NemaShield? treatments produced the tallest plants and the greatest root/shoot dry weights, but due to the high level of variability treatments were not statistically different. The two media treatments were Sunshine? SB 300 (a peat-lite mix) and a peat-lite/rice hull mixture formulated by a local grower. Media treatments were significantly different for plant height--taller plants were produced with the peat-lite/rice hull mixture.

Back to top of web page

III. George Heimpel, Dept. of Entomology, Univ. of Minnesota, St. Paul, MN 55108, tel. (612) 624-3480,FAX:(612) 625-5299, email: heimp001@tc.umn.edu

Project Title: Parasitoid sugar feeding and biological control.

Investigators: Jana Lee, George Heimpel

Contact: Jana Lee (leex1228@umn.edu)

Project Description: In cabbage systems, the majority of parasitic hymenoptera (65-70%) have fed on sugar sources in fields with and without buckwheat plantings (Lee & Heimpel 2003). The lack of treatment effects may have been due to wasps actively dispersing between fields. In the following years, we established fields at least half a mile apart to prevent cross-treatment movement. The Diamondback moth parasitoid Diadegma insulare (Hymenoptera: Ichneumonidae) fed more on sugar in fields with buckwheat than controls (90% vs. 70%). However, a higher incidence of feeding did not lead to higher parasitism rates. Therefore, in 2002-2003, we tested whether the presence of buckwheat enhanced the longevity and fecundity of D. insulare in the field and whether feeding status affected the likelihood of D. insulare to disperse from a cabbage patch. We also examined the effects of other common food sources, such as soybean aphid honeydew from surrounding areas, on D. insulare in a laboratory study. Buckwheat nectar was superior to soybean aphid honeydew, D. insulare lived twice as long and maintained higher sugar and lipid reserves (Lee et al., submitted).

Project Title: Potential of a natural enemy to influence the evolution of resistance in European corn borer to Bt corn.

Investigators: Cynthia (Simon) Hsu, George Heimpel

Contact: Cynthia Hsu (hsux0049@umn.edu)

Description: Simon Hsu’s work is focused on understanding the behavior of a parasitoid, Macrocentus grandii, in relation to the spatial patterns of its host, the European corn borer, Ostrinia nubilalis, and how this parasitoid might influence the evolution of resistant to Bt corn by differentially impacting susceptible and resistant individuals. It is hypothesized that limited dispersal and/or a strong positive density dependent response by M. grandii could create a spatial refuge for resistant corn borers, favoring an increase in the frequency of the resistant genotype, while a high dispersal ability and/or a strong inverse density dependent response may decrease the number of resistant larvae that survive in a Bt field. Current work focuses on measuring the short-range dispersal of M. grandii within a corn field that has two host densities. In this experiment, 40-acre fields are split in half with one half of the field containing a low density of hosts while the other half has a high density of hosts. A strip of corn between the two halves is labeled using rubidium chloride (RbCl). Parasitoids emerging from this strip are labeled with RbCl and adult parasitoids are recaptured at different distances into the two halves. Results from this experiment will be used to determine whether the dispersal behavior of the parasitoid depends on host density, and to estimate the dispersal-distance relationship for M. grandii over short distances (i.e. up to 137 meters) for each of the two densities. The second project focuses on detecting density dependence using a spatial pattern analysis of the distribution of corn borers and occurrence of parasitism by M. grandii. Results from these experiments will be used to determine whether M. grandii demonstrates density dependent parasitism, whether the ability to detect density dependence is scale-dependent, and whether spatially explicit analysis methods for detecting density dependence are more sensitive than spatially implicit analyses. The third project investigates whether a corn borer larva in a Bt corn field is at higher or lower risk of being parasitized than a larva in a non-Bt field as a function of dispersal of the parasitoid and local host density. Results from these experiments will be used to parameterize a model testing whether these behaviors can influence how quickly corn borers develop resistance to Bt corn.

Project title: Biological control of Soybean aphid, Aphis glycines.

Investigators: George Heimpel, Zhishan Wu, collaborators in Japan (Drs. Kagawa, Tuda).

Contact: George Heimpel (heimp001@umn.edu)

Project description: In the summer of 2003, we evaluated the releases of the ‘Wyoming’ strain of Aphelinus albipodus for successful overwintering of the parasitoid. Although A. albipodus were found attacking both soybean aphids and Rhopalosiphum padi in corn, molecular analyses showed that these were not descendents of the released individuals. We therefore have no evidence that successful overwintering took place. Observations within soybean fields during soybean aphid outbreaks in the summer of 2003 revealed parasitism by at least 3 species (in order of importance): Lysiphlebus testaceipes, A. asychis and A. albipodus. Parasitism rates by L. testaceipes exceeded 30% at some sites. We are in the process of doing host range studies of Lipolexis gracilis and a Tryoxis sp. in the Minnesota quarantine laboratory and expect shipment of 3 additional aphidiine species collected in China and Korea from the Delaware laboratory within the next few months. Three trips to Japan were undertaken during 2002 – 2003. Observations during these visits suggested that A. albipodus overwinters using alternative aphid species in the vicinity of soybean fields, and not on Rhamnus spp.

Biological Control Publications since 2002 – Heimpel lab

Hoogendoorn, M. & G.E. Heimpel. 2002. Indirect interactions between an introduced and a native ladybird beetle species mediated by a shared parasitoid. Biological Control 25: 224-230.
Lundgren, J.G., G.E. Heimpel & S.A. Bomgren. 2002. Comparison of Trichogramma brassicae (Hymenoptera: Trichogrammatidae) augmentation with organic and synthetic pesticides for control of cruciferous Lepidoptera. Environmental Entomology 31: 1231-1239.
Heimpel, G.E., C. Neuhauser & M. Hoogendoorn. 2003. Effects of parasitoid fecundity and host resistance on indirect interactions in host-parasitoid population dynamics. Ecology Letters 6: 556-566.
Lundgren, J.G. & G.E. Heimpel. 2003. Quality assessment for three species of commercially-produced Trichogramma. Biological Control 26: 68-73.
Neuhauser, C., D.A. Andow, G.E. Heimpel, G. May, R. Shaw & S. Wagenius. 2003. Community Genetics – expanding the synthesis of ecology and genetics. Ecology 84: 545-558.
Jervis, M.A., P. Ferns & G.E. Heimpel. 2003. Body size and the timing of reproduction in parasitoid wasps: a comparative analysis. Functional Ecology 17: 375-383.
Antolin, M.F., P.J. Ode, G.E. Heimpel, R.B. O'Hara & M.R. Strand. Population genetics, mating system, and sex allele diversity of the parasitoid Bracon hebetor (Say) (Hymenoptera: Braconidae). Heredity 91: 373-381.
Wu, Z., K.R. Hopper, P.J. Ode, R.W. Fuester, J. Chen & G.E. Heimpel. Complementary sex determination in hymenopteran parasitoids and its implications for biological control. Entomologica Sinica 10: 81-93.
Koch, R., W.D. Hutchison, R. Venette & G.E. Heimpel. 2003. Susceptibility of immature Danaus plexippus (Lepidoptera: Nymphalidae) to predation by Harmonia axyridis (Coleoptera: Coccinellidae). Biological Control 28: 265-270.
Hoogendoorn, M. & G.E. Heimpel. 2003. PCR-based cut content analysis of insect predators: using ribosomal ITS-1 fragments from prey to estimate predation frequency. Proceedings of the 1st International Symposium on Biological Control of Arthropods. Honolulu, Hawaii, 1/2002. Pp. 91 – 97.
Lee, J.C. & G.E. Heimpel. 2003. Sugar feeding by parasitoids in cabbage fields and the consequences for pest control. Proceedings of the 1st International Symposium on Biological Control of Arthropods. Honolulu, Hawaii, 1/2002. Pp. 220 – 225.
Lundgren, J.G. & G.E. Heimpel. 2003. Augmentation of Trichogramma brassicae for Control of Cruciferous Lepidoptera. Proceedings of the 1st International Symposium on Biological Control of Arthropods. Honolulu, Hawaii, 1/2002. Pp. 160 – 166.
Heimpel, G.E., J.C. Lee & Z. Wu. 2003. Field oviposition rates in sugar-fed and sugar-starved parasitoids. Proceedings of 12th International Entomophagous Insects Workshop. Journal of Insect Science 3:33. http://www.insectscience.org/3.33/
Vickery, J. & G.E. Heimpel. 2003. Biological control of musk thistle: is it worth the risk?. The Thicket! An online newsletter of the IPM division of the Minnesota Dept. of Agriculture. Volume 2 no. 1 – Winter 2003. http://www.mda.state.mn.us/ipm/thicket/v2n1a5.htm
Jervis, M.A. & G.E. Heimpel. 2004. Phytophagy. In Jervis, M.A. & N.A.C. Kidd (eds.): Insect Natural Enemies: Practical Approaches to their study and evaluation, 2nd ed. Kluwer Press. (in press).
Heimpel, G.E. & M.A. Jervis. 2004. A critical evaluation of the hypothesis that supplemental nectar improves biological control by parasitoids. In: Wäckers, F., van Rijn, P. & Bruin, J., Plant-provided food and plant-carnivore mutualism. Cambridge University Press. (in press).
Jervis, M.A., J.C. Lee & G.E. Heimpel. 2004. The role of life history studies. In: G. Gurr, S. Wratten & M. Altieri (eds.), Habitat Manipulation and Arthropod Pest Management, CSIRO Press (in press).
Wu, Z., Schenk-Hamlin, D., Zhan, W., Ragsdale, D.W. & G.E. Heimpel. The soybean aphid in China – an historical review. Annals of the American Entomological Society (accepted).
Heimpel, G.E., D.W. Ragsdale, R. Venette, K.R. Hopper, R.J. O’Neil, C. Rutledge & Z. Wu. Prospects for importation biological control of the soybean aphid: anticipating potential costs and benefits. Annals of the American Entomological Society (accepted).
Hoogendoorn, M. & G.E. Heimpel. Competitive interactions between an exotic and a native ladybeetle: a field cage study. Entomologia Experimentalis et Applicata (accepted).
Heimpel, G.E., J.C. Lee, Z. Wu, L. Weiser, F. Waeckers & M.A. Jervis. Gut Sugar Analysis in Field-Caught Parasitoids: Adapting Methods Originally Developed for Biting Flies. International Journal of Pest Management (accepted).
Lee, J.C., G.E. Heimpel & G. Leibee. Comparing floral nectar and aphid honeydew diets on the longevity and nutrient levels of a parasitoid wasp. Entomologia Experimentalis et Applicata (in review).

Back to top of web page

IV. William Hutchison, 219 Hodson Hall, 1980 Folwell Ave, University of Minnesota, St. Paul, MN 55108, phone: (612) 624-9272, fax: (612) 625-5299, E-mail: hutch002@tc.umn.edu

Project title: Susceptibility of immature Danaus plexippus (Lepidoptera: Nymphalidae) to predation by Harmonia axyridis (Coleoptera: Coccinellidae).

Investigators: Robert Koch, William Hutchison, Robert Venette

Contact: Robert Koch (koch0125@tc.umn.edu)

Project description: We continued to evaluate the risks of predation by the exotic coccinellid, Harmonia axyridis (Pallas), on the monarch butterfly, Danaus plexippus L., in agroecosystems. The likelihood of D. plexippus co-occurring with H. axyridis is being examined at an infield scale and a continental scale. We finished our third summer of monitoring the phenologies of D. plexippus and H. axyridis on milkweed plants in cornfields. Preliminary analyses indicate that a moderate level of exposure may exist at the whole field scale. However, on an individual plant scale, exposure appears to be lower. As an initial step toward evaluating the potential geographic range of H. axyridis, we (in collaboration with Mario Carrillo and Colleen Cannon) have been examining its cold hardiness (i.e., supercooling point and lower lethal temperature). For laboratory reared individuals, supercooling points for non-feeding stages (i.e., larvae and adults) (–20 to –25ºC) were lower than the supercooling points for feeding stages (i.e., eggs and pupae) (–15ºC). In winter, field collected H. axyridis super cooled at –25ºC, and the temperature required to kill 50% of H. axyridis was about –25ºC.
We are also evaluating the likelihood that H. axyridis will prey upon D. plexippus. Laboratory functional response data indicate that third instar H. axyridis can consume about 25 D. plexippus eggs and 15 D. plexippus first instars in 24h. H. axyridis adults consumed up to about 30 D. plexippus eggs in 24 h. An infield, caged predation study with D. plexippus as prey and varying densities of third instar H. axyridis as predators showed that the survival of D. plexippus decreased with increasing densities of H. axyridis. A similar series of caged studies were conducted in 2002 and 2003, however Aphis nerii was included as an alternate prey. Data from these studies continue to be analyzed.

Biological Control Publications since 2002 – Hutchison lab

Koch, R.L. 2003. The multicolored Asian lady beetle, Harmonia axyridis: A review of its biology, uses in biological control, and non-target impacts. Journal of Insect Science 3(32): 16pp. http://www.insectscience.org/3.32/
Koch, R.L., W.D. Hutchison, R.C. Venette, and G.E. Heimpel. 2003. Susceptibility of immature monarch butterfly, Danaus plexippus (Lepidoptera: Nymphalidae: Danainae), to predation by Harmonia axyridis (Coleoptera: Coccinellidae). Biological Control 28(2): 265-270.
Koch, R.L. and W.D. Hutchison. 2003. Phenology and blacklight trapping of the multicolored Asian lady beetle (Coleoptera: Coccinellidae) in a Minnesota agricultural landscape. Journal of Entomological Science 38(3): 477-480.

Back to top of web page

V. Vera Krischik, 219 Hodson Hall, 1980 Folwell Ave., University of Minnesota, St. Paul, MN 55108, Phone: 612-625-7044, E-mail: krisc001@maroon.tc.umn.edu

Project title: IMP of Midwest Landscapes

Investigator: Vera Krischik, University of Minnesota

Contact: Vera Krischik (krisc001@umn.edu)

Project description: "IPM of Midwest Landscapes" is out for review and will be published as soon as suggested edits are received and processed. The manual will be printed in color and prepublishing copies can be ordered at a reduced rate of $30 (retail price $45) from Dr. Susan Ratcliffe, University of Illinois, NC IPM Coordinator, phone (217) 333-9656. Mike Fitzner, CSREES, asked that the book was sent for review by NCR125, and members Dan Mahr and George Heimpel received copies. Members of NCR 193, " Maintaining plant health: Managing pests of landscape plants" have cooperated on this IPM manual for Midwest landscapes. This manual is a highly needed for educating growers, landscapers, managers, and consumers in the principles of IPM and its application to managing over 200 insect species in Midwest landscapes. Presently, no comprehensive manual is available for the Midwest. The manual promotes the proper timing of pesticides with the life history of the pest, conservation of biological control agents, and the use of biorational pesticides.

Back to top of web page

VI. Timothy J. Kurtti, 219 Hodson (office), University of Minnesota, 1980 Folwell Avenue, St. Paul, MN, 55108, Phone: (612) 624-4740, Email: kurtt001@umn.edu

Project title: Interaction of Entomopathogenic Fungi and Black Legged Ticks, Ixodes Scapularis (Acari: Ixodidae)

Investigators: Lina B. Flor, Timothy J. Kurtti

Contact: Lina B. Flor (flor0119@umn.edu)

Project description: This project is focused on the mitosporic fungi that infect black legged ticks in Minnestoa. In nature, ticks are attacked by a number of fungi, most of them under Class Deuteronomycetes. We are currently working on the morphological and molecular characterization of the fungus we collected infecting black legged ticks. These experiments will ascertain us the identity of the fungus and how is it related to some other fungal strains of the same species infecting other organisms. The second study we are working is on the pathogenesis of the fungi on I. scapularis. This is to compare the pathogenic activity of the fungus on ticks to determine which is more susceptible to fungal infection, when they are fed or unfed? A part of the study will also look on the pathogenesis, focusing on the adherence, point of entry, penetration and proliferation of the fungus on ticks. The third study will be on the physiological test of the fungal isolate infecting I. scapularis. This is to determine the ability of the fungal isolate from ticks to grow at different temperature range and its tolerance to UV.

VII. Roger Moon, 422 Hodson (office), 441 Hodson (lab), University of Minnesota, St. Paul, MN 55108, Phone: (612) 624-2209, E-mail: rdmoon@maroon.tc.umn.edu

Project title: Pre-release evaluations of exotic filth fly parasitoids

Investigators: Roger D. Moon¹ and Chris J. Geden^2
1Department of Entomology, U of MN, St. Paul
²Center for Medical, Agricultural and Veterinary Entomology, USDA-ARS, Gainesville

Contact: R. Moon (rdmoon@ umn.edu)

Project description: Colonies of Old World Spalangia and Muscidifurax from Russia and Kazakhstan were maintained in quarantine facilities at Center for Medical, Agricultural and Veterinary Entomology, and colonies of MN isolates of the same species were maintained in Minnesota. Morphometric measurements of selected structures on the antenna, thorax and wing revealed no gross differences among isolates of each species from the three geographic regions.
A laboratory experiment compared willingness of females of MN Muscidifurax raptor, Spalangia endius, and S. cameroni to oviposit and develop in freeze-killed vs living house fly puparia of two different strains of house flies, wild vs. ochre eye. Freeze-killed and living hosts were equally suitable for Muscidifurax, but the two Spalangia spp. were reluctant to oviposit on frozen hosts. The two strains of house flies were equally acceptable and suitable for all three of the parasite species. These results indicate fresh hosts must be used in studies planned to evaluate biological traits of endemic and exotic Spalangia when released from quarantine.
A series of experiments to evaluate host range was begun with quarantined material in Florida. Sets of 5 females of a given parasite were presented with 100 puparia of a given host in a forced-use assay. Parasites assayed (and geographic origin) were S. nigroaenea (RU, KZ), S. cameroni (RU, KZ, FL), S. endius (RU, KZ, FL), M. raptor (RU, KZ, FL) and Trichopria sp. (RU, KZ). Candidate hosts were house fly, stable fly, a flesh fly (Sarcophaga bullata), and black garbage fly.

Back to top of web page

VIII. David Ragsdale, 219 Hodson Hall, 1980 Folwell Ave.,University of Minnesota, St. Paul, MN 55108, phone: (612) 624-6771, FAX: (612) 625-5299, E-mail: ragsd001@maroon.tc.umn.edu

Project title: Assessing the Establishment of Aphthona spp. Released for Control of Leafy Spurge, Euphorbia esula L., in Minnesota

Investigators: Luke C. Skinner¹, Monika Chandler^1,2, Dharma Sreenivasam², David Ragsdale^1,2
1Department of Entomology, U of MN, St. Paul
²Center for Medical, Agricultural and Veterinary Entomology, USDA-ARS, Gainesville

Contact: D. Ragsdale (ragsd001@tc.umn.edu)

Project description: Research was completed on evaluating the success of establishment of Aphthona spp. for control of leafy spurge, Euphorbia esula L., in Minnesota. The was the Ph.D. dissertation of Luke Skinner who completed and defended his dissertation in December 2002. Day degree emergence models have been constructed for A. lacertosa and A. nigriscutis using laboratory data to set the lower developmental threshold. Phenology models based on air temperature were developed to predict peak emergence of A. lacertosa and A. nigriscutis. From this model we can provide resource managers with estimated dates on peak emergence so that they can collect beetles for redistribution when they are most abundant and before significant egg laying has occurred.

Project title: Landscape-scale and within wetland movement of Galerucella spp. introduced for management of purple loosestrife (Lythrum salicaria L.)

Investigators: Brian P. McCornack, Luke C. Skinner, and David Ragsdale

Contact: D. Ragsdale (ragsd001@tc.umn.edu)

Project description: Galerucella calmariensis L. and G. pusilla Duft were introduced into the United States to control purple loosestrife (Lythrum salicaria L.), an invasive species capable of colonizing wetland ecosystems and displacing native vegetation. Larvae and adults defoliate plants resulting in reduced seed production, stem densities, and ultimately in root crown death. Distribution of beetles within and between wetlands is not well understood. Our objectives were to: 1) map beetle dispersal within a wetland, 2) correlate beetle populations with control of purple loosestrife, and 3) increase efficiency in release efforts by assessing landscape-scale dispersal and colonization of Galerucella spp. In the spring of 2001 and 2002, GPS and GIS technologies were used to map the movement dynamics of Galerucella spp. within each of four wetlands. We also examined the ability of Galerucella spp. adults to disperse from their original release site to other neighboring, noncontiguous, loosestrife-infested wetlands. Geographic regions that contained numerous, noncontiguous loosestrife infested wetlands with at least one site within the region where Galerucella beetles became established were used in this landscape-scale study. Within a wetland we noted that Galerucella spp. dispersed throughout the site within 2 years after initial release. In the landscape-scale study, over 160 sites were sampled in 7 counties. Beetles dispersed up to 7 km and colonized more than 50% of the non-contiguous wetlands from the original release site. Currently, we recommend that resource managers concentrate insect redistribution efforts to wetlands greater than 7 km from known release sites.

Project Title: Biological Control of Garlic Mustard: Host Specificity of Ceutorynchus spp. on native mustards.

Investigators: Jeanie Katovich, Roger Becker, Brian P. McCornack, Luke C. Skinner, and David Ragsdale

Contact: D. Ragsdale (ragsd001@tc.umn.edu)

Project description: The objectives of this newly funded project (started in October 2003) was to determine if several weevils, Ceutorynchus spp., identified by colleagues at CABI as garlic mustard specialists, will feed and reproduce on native species of mustard (Brassicaceae). The mustard species to be tested are unique to the North Central region of the United States and will expand the list of mustard species included in current host specificity testing of Ceutorynchus spp. conducted in at the CABI facility in Switzerland and at the University of Minnesota.

Biological Control Publications since 2002 – Ragsdale lab

Skinner, L.C. 2002. Assessing the Establishment of Aphthona spp. Released for Control of Leafy Spurge, Euphorbia esula L., in Minnesota, Ph.D. Dissertation,
Ragsdale, D. W., D. V. Voegtlin and R. J. O’Neil. 2004. Soybean Aphid Biology in North America. Annals Entomol. Soc. Amer. 97: (in review, AN-03-148).
Heimpel G. E., D. W. Ragsdale, R. C. Venette, K. Hopper, R. J. O’Neil, C. Rutledge, and Z. Wu. 2004. Prospects for importation biological control of the soybean aphid: anticipating potential costs and benefits, Ann. Entomol. Soc. Amer. 97: (accepted for publication, AN-03-056)
Wu, Z., D. Schenk-Hamlin, Zhan, D. W. Ragsdale and G. E. Heimpel. 2004. The soybean aphid in China – an historical review. Ann. Entomol. Soc. Amer. 97: (accepted for publication AN-03-055)
Skinner, L.C., D.W. Ragsdale, R.W. Hansen, M.A. Chandler and R.D. Moon. 2004. Temperature-dependent development of overwintering Aphthona lacertosa and A. nigriscutis (Coleoptera: Chrysomelidae), two flea beetles introduced for the biological control of leafy spurge, Euphorbia esula. Environmental Entomology (accepted for publication, EE-03-1007).
Radcliffe, E. B., D. W. Ragsdale and R. A. Suranyi. 2003. IPM case studies – seed potato, In. Aphids as Crop Pests, H. F. van Emden and R. Harrington [eds.]. CABI Publishing, Wallingford, U.K. (accepted for publication)
Ruano-Rossil, J. M., E. B. Radcliffe, D. W. Ragsdale. 2003. In: Dedryver, et. al. (eds), Disruption of entomopathogenic fungi of green peach aphid, Myzus persicae (Sulzer), by fungicides used to control potato late blight, Aphids in a New Millenium, 6th Int. Sympos. On Aphids, Rennes, France, 2-7 Sept., 2001 (accepted for publication).
Radcliffe, E. B. and D. W. Ragsdale. 2002. Aphid transmitted potato viruses: the importance of understanding vector biology. Amer. J. Pot. Res. 79:353-386.
Legg, D. E., S. M. Van Vleet, D. W. Ragsdale, R. W. Hansen, B. Chen-Charpentier, L. Skinner, and J. E. Lloyd. 2002. Required number of location-years for estimating functional lower developmental thresholds and required thermal summations of insects: first emergence of Apthona nigriscutis Foudras as an example. International Journal of Pest Management, (In press) Accepted for publication, October 2001.
Legg, D. E., S. M. Van Vleet, D. W. Ragsdale, R. W. Hansen, and J. E. Lloyd. 2002. Phenology Models for first emergence of aldult Apthona nigriscutis (Coleoptera: Chrysomelidae), a biological control agent of leafy spurge (Euphorbiaceae). Environ. Entomol. 31: 348-353.

Back to top of web page

IX. Ray Newman, Department of Fisheries and Wildlife, University of Minnesota, St. Paul, MN 55108, Phone: 612-625-5704, Internet:rmn@fw.umn.edu

Project Title: Research on the Biological Control of Myriophyllum spicatum

Investigators: Ray Newman, University of Minnesota Dept. of Fisheries and wildlife

Contact: R. Newman (rmn@fw.umn.edu)

Project description: Our main focus at the moment is determining what limits populations of the milfoil weevil (likely high sunfish densities in some lakes) and what is the role of plant community response and competition in successful biological control of Eurasian watermilfoil. We have shown that herbivores can cause sustained declines of Eurasian watermilfoil when milfoil weevil populations remain high, but predation by sunfish appears to limit herbivore populations in many lakes.  We have also isolated and identified several water soluble chemicals released by Eurasian watermilfoil that are used by the milfoil weevil to locate its hostplant. Detailed information is available at the following web site: http://www.fw.umn.edu/research/milfoil/milfoilbc/. Reports (including our completion report for 1999-2001) are available at: http://www.fw.umn.edu/research/milfoil/milfoilbc/currentresearch.html#reportsavail_in_pdf

Biological Control Publications since 2002 – Newman lab

Getsinger, K.D., A. G. Poovey, W.F. James, R. M. Stewart, M.J. Grodowitz, M.J. Maceina, and R.M. Newman.  2002.  Management of Eurasian watermilfoil in Houghton Lake, Michigan: workshop summary. Technical Report ERDC/EL TR-02-24, U.S. Army Engineer Research and Development Center, Vicksburg, MS.  88 pgs.
Newman, R.M.  In press.  Biological control of Eurasian watermilfoil by aquatic insects: basic insights from an applied problem.  Archiv für Hydrobiologie.
Getsinger,  K., M. D. Moore, E. Dibble, E. Kafcas, M. Maceina, V. Mudrak, C. Lembi, J. Madsen, R. M. Stewart, L. Anderson, W. Haller, C. Layne, A. Cofrancesco, R. Newman,  F. Nibling, K. Engelhardt.  In press. Best Management Practices Handbook for Aquatic Plant Management in Support of Fish and Wildlife Habitat.  Aquatic Ecosystem Restoration Foundation, Lansing, MI.

Back to top of web page

X. Minnesota Dept. of Agriculture

Project title: Weed Integrated Pest Management

Investigators: Anthony Cortilet and Monika Chandler, Minnesota Department of Agriculture:

Contact:Anthony Cortilet (Anthony.Cortilet@state.mn.us) or Monika (mchandle@mda.state.mn.us)

Project description: This project coordinates biological control efforts for targeted weeds such as leafy spurge and spotted knapweed. In addition, this project conducts applied research projects—currently one is underway for spotted knapweed. This project also conducts statewide weed surveys and maintains a weed database that features weed information and release data for participating MN counties. It can be found at www.mda.state.mn.us/weedcontrol/. This project also publishes THICKET!, a bi-annual electronic newsletter produced by the Weed IPM Working Group. THICKET! is found at http://www.mda.state.mn.us/ipm/thicket/.

Back to top of web page

XI. Luke Skinner, Minnesota Dept. of Natural Resources (DNR) and Dept. of Entomology, Univ. of Minnesota, St. Paul MN 55108, skin0034@tc.umn.edu

Project title: Management of Purple Loosestrife in Minnesota

Investigator: Luke Skinner

Contact: Luke Skinner (skin0034@tc.umn.edu)

Project description: Leaf-Eating Beetles (Galerucella spp.): From 1992-2003, more than 8 million Galerucella spp. have been released on 800+ sites in Minnesota. In 2002, a survey of 234 release sites suggest that 90% sites have established reproducing populations of Galerucella spp. Insect populations increased significantly at many locations with pronounced damage to loosestrife plants. At 45% (105 sites) of the sites surveyed, the insect populations are rapidly increasing and causing significant damage to the loosestrife infestations. At 21% of all visited sites, the loosestrife was severely defoliated (90-100%).
With success of insect establishment in the field, organized rearing efforts are anticipated to come to an end in the next several of years. Resource managers are able to collect insects from established release sites and redistribute to new infestations. This “collect and move” method will reduce the effort and costs needed to further distribute leaf-eating beetles in Minnesota.
Root-Boring Weevils: Initially, only a small number of root-boring weevils were brought to Minnesota. As of December 2002, there are 12,223 weevils comprising 30 releases, at 23 different sites. In 2001, Cornell University provided 2,000 adult root-boring weevils for field release. The weevils were released at four sites (two in Hennepin County by Minnesota Valley NWR and two in Sherburne County by DNR and Sherburne NWR). A fall survey of two weevil release sites (Hugo and New Brighton -2001) revealed that the weevils have established and are reproducing.
The MN DNR website was substantially updated in the spring of 2003. See: http://www.dnr.state.mn.us/ecological_services/exotics/plprog.html

Selected journal publications and technical reports

see also http://www.dnr.state.mn.us/ecological_services/exotics/plprog.html

Back to top of web page

View reports from other state