1980 Folwell Avenue
St Paul, MN 55108
M.S. Department of Zoology, University of Maryland, College Park, MD.
Ph.D. Department of Entomology, University of Maryland, College Park, MD.
Areas of Interest
Conservation biocontrol, insecticide toxicity, pesticide use and safety, IPM programs for pests in landscapes and greenhouses
ENT 4015 Ornamental and Turf Entomology, from 2000 to 2014
ENT 5009/previously HORT 5009, Pesticides, from 2005 to 2014
Yearly Extension/outreach teaching
January, with MNLA, MGSA Green Expo for the MN Horticultural industry
March, with MN Christmas tree association winter meeting
March, with MDA, MNLA Biocontrol and insecticide compatibility in nursery and greenhouse workshop
March, April, with MNLA Two to three Online and in-person workshop on learning technical information to pass the MN pesticide license exam in categories A and E
July, with MDA, Christmas tree association summer meeting
November, with MDA, MNLA recertification workshop for categories A and E
Every month talks to state agencies, state and national commodity workshops, master gardeners, garden clubs, bee or garden related NGO
The Krischik lab supports research on pollinator conservation, integrated pest management, effects of pesticides on pollinators, and developing best practices for pollinators. We work on monarch butterflies, painted lady butterflies, bumble bees, and Japanese beetles. See websites for more information.
2017 to 2020 research on the effects of four common insecticides on monarch and painted lady butterflies and bees and residue of insecticides near agricultural fields and in ornamentals.
Effects of acute insecticide exposure on butterflies
The purpose of this study was to examine the lethal effects of four insecticides on monarch butterflies (Danaus plexippus) and painted lady butterflies (Vanessa cardui). Acute exposure bioassays were carried out to determine LC50 values for monarch and painted lady larvae exposed to bifenthrin (pyrethroid), chlorantraniliprole (ryanoid), clothianidin (neonicotinoid), and imidacloprid (neonicotinoid), and painted lady adults exposed to clothianidin. We found that chlorantraniliprole was the most toxic insecticide for both species; for monarch larvae, the LC50 for chlorantraniliprole was 5-20x lower than that of the other insecticides, while for painted lady larvae it was 20-9000x lower. Additionally, although painted lady larvae were more sensitive than monarchs to chlorantraniliprole, monarch larvae were substantially more sensitive to the other three insecticides.
Effects of chronic insecticide exposure on butterflies
Chronic exposure bioassays were carried out to evaluate sublethal effects of clothianidin (neonicotinoid) on monarch (Danaus plexippus) and painted lady (Vanessa cardui) butterflies. Butterfly larvae were fed treated (0-40 ppb) foliage from third instar to pupation. We found that 40 ppb clothianidin significantly reduced the number of larvae that pupate for both monarchs and painted ladies. In addition, 40 ppb clothianidin resulted in greater mean days to pupation for monarch larvae, while there was no significant effect for painted lady larvae.
Effects of chronic insecticide exposure on bumble bees
Declines in bee populations around the world have been attributed to various factors, one of which is pesticide use. The purpose of this project was to examine the toxicity of several insecticides to bumble bees (Bombus impatiens). We found that chlorantraniliprole (4 ppm), an insecticide commonly used for Japanese beetle control, was less toxic to bees than the neonicotinoid clothianidin (0.02 ppm). Allso, clothianidin resulted in a decrease in brood production and movement.
Pesticide residues in wildflowers near crops
Pesticide drift from agricultural applications can be a source of harmful pesticide exposure for pollinators. In this project, we sampled wildflowers on the margins of potato, soybean, and corn fields. For wildflower samples collected on habitat near potato fields in MN, we found that 100% of 36 samples had at least one pesticide and as many as 15 different pesticides.
Pesticide residues in ornamentals
Imidacloprid (neonicotinoid) is an insecticide commonly used in ornamental plants. The purpose of this study was to measure imidacloprid residue levels in ornamentals based on the label application rate, which is often higher than the rate for agricultural applications. We found that imidacloprid residue levels in ornamentals were significantly higher than neonicotinoid residues near agricultural fields.
20201 to 2021 research on the effects of a soil inhabiting pathogen and the effects of microbial insecticides on Japanese beetles
2021 Japanese beetle biocontrol
The spraying of insecticides on bee lawns for JB grubs and on leaves and flowers for JB adults, probably results in the most insecticide used in urban and park lands, which may have non-targeted consequences for pollinators. Fortunately, JB has a natural biocontrol agent that was discovered in 1988 in Connecticut that kills JB grubs and reduces reproduction in adult females that needs to be introduced into MN. The microsporidian (fungal) pathogen called Ovavesicula popilliae was studied at Michigan State University (MSU) and released in five states, Arkansas, Colorado, Kansas, Kentucky, and Michigan. For the long term, research is needed to survey greater MN for the presence of JB and the pathogen, which so far was found in two locations in Stillwater and UM Experiment Station Campus in Saint Paul. MN. Research is underway to identify, culture, and disseminate the biocontrol pathogen. For the short term, integrated pest management (IPM) programs using pollinator friendly chlorantraniliprole and microbial insecticides need to be developed that conserve pollinators and kill JB. However, recent research showed that chlorantraniliprole is highly toxic to larval and adult butterflies.
Prouty Cody, Paola Barriga, Andrew K. Davis, Vera Krischik, and Sonia Altizer. 2021. Host plant species mediates impact of neonicotinoid exposure to monarch butterflies. Insects 2021, 12, 999. https://doi.org/10.3390/ insects12110999
Krischik Vera, 2021 submitted. Field insecticide residues, acute and chronic bioassays with bumblebee, honeybees, monarch, and painted lady butterfly, Vera Krischik, Matt Lagus, Temo Balaxashvili, Nick Partington, submitted, in revision
Cody Prouty, Lewis Bartlett, Vera Krischik, and Sonia Altizer. Adult monarch butterflies show high tolerance to neonicotinoid. 2021 in MS.
Peer Reviewed Publications
1. Krischik Vera, 2021 submitted. Field insecticide residues, acute and chronic bioassays with bumblebee, honeybees, monarch, and painted lady butterfly, Vera Krischik, Matt Lagus, Temo Balaxashvili, Nick Partington, submitted, in revision
2. Prouty Cody, Paola Barriga, Andrew K. Davis, Vera Krischik, and Sonia Altizer. 2021. Host plant species mediates impact of neonicotinoid exposure to monarch butterflies. Insects 2021, 12, 999. https://doi.org/10.3390/ insects12110999
3. Krischik, V, MR Zbinden, CC Reed. Conservation of beneficial insects with native compared to bedding plants. Submitted Sustainable Cites; reorganizing with new data to submit to Hort. Sciences
4. Griffin, JJ, WR Jacobi, and ….VKrischik. 2017. Ten year performance of elms at the National Elm Trials, Arboriculture and urban forestry J Arboriculure 43(3): May 2017
5. Krischik V, M Rogers, G Gupta, AVarshney. 2015. Soil-applied imidacloprid is translocated to ornamental flowers and reduces survival of adult Coleomegilla maculata, Harmonia axyridis, and Hippodamia convergens lady beetles, and larval Danaus plexippus and Vanessa cardui, PLoS ONE March 23, 2015, DOI: 10.1371/journal.pone.0119133
6. Scholer J and V Krischik. 2014. Chronic exposure of imidacloprid and clothianidin reduce queen survival, foraging, and nectar storing in colonies of Bombus impatiens. PLoS ONE 93): e91573. doi:10.1371/journal.pone.0091573
7. Tenczar, E and V Krischik. 2007. Comparison of standard granular and drench) and novel tablet, stick soak, root dip) imidacloprid treatments for cottonwood leaf beetle management on hybrid poplar J. Econ. Entomol. 100: 1611-1621.
8. Krischik, V, A Landmark, G Heimpel. 2007. Soil-applied imidacloprid is translocated to nectar and kills nectar-feeding Anagyrus pseudococci Girault) Hymenoptera: Encyrtidae) J. Environ. Entomol. 365): 1238-1245.
9. Tenczar, E and V Krischik. 2007. Effects of ninebark phytochemistry on Calligrapha spiraea Say) Coleoptera:Chrysomelidae). Hort Sci. 426): 1396–1399.
10. Rogers, ML Martin, and V Krischik. 2007. Effects of soil application of imidacloprid on survivorship of adult green lacewing, Chrysoperla carnea Neuroptera: Chrysopidae), used for biological control. Biological Control 42: 172-177.
11. Gupta, G and V Krischik. 2007. Professional and consumer insecticides for the management of adult Japanese beetle. J. Econ. Entomol. 100: 830-839.
12. Robbins, PS, V.Krischik, and 12 others. 2006. Trapping Phyllophaga spp. Coleoptera: Scarabaeidae: Melolonthinae) using sex attractants. J. Insect Science 639):1-124.
13. Tenczar, E and V Krischik. 2006. Management of cottonwood leaf beetle, Chysomela scripta Coleoptera:Chrysomelidae) with a novel transplant soak and biorational insecticides to conserve coccinellid beetles. J. Econo. Entomol.991):102-108.
14. Smith, SF and VA Krischik. 2000. Effects of biorational pesticides on four coccinellid species Coleoptera: Coccinellidae). J.Econ. Entomol. 933):732-736.
15. Smith, SF and VA Krischik. 1999. Effects of systemic imidacloprid on Coleomegilla maculata. Coleoptera: Coccinellidae). Environ.Entomol. 286):1180-1195.
16. Findlay, S, M Carreiro, VA Krischik, and CG Jones. 1996. Leaf damage affects leaf litter quality. Ecological Applications 61): 269-275
17. Jones, CG , RF Hopper, JS Coleman, and VA Krischik. 1993. Plant vascular architecture controls the distribution of a systemically induced defense. Oecologia 93: 452-456.
18. Coleman, JS, CG Jones, and VA Krischik. 1992. Phytocentric and exploiter perspective on phytopathology. Advances in Plant Pathology 8: 149-195.
19. Krischik, VA, R Goth and P Barbosa. 1991. Generalized plant defense: Effects on multiple species. Oecologia 85: 562-571.
20. Mueller, D, L Pierce, H Benet, and VA Krischik. 1991. The practical application of pheromone traps in the food and tobacco industry. Journal of the Kansas Entomological Soc. 63: 548-553.
21. Krischik, VA and RF Denno. 1990. Patterns of growth, reproduction, defense and herbivory in the dioecious shrub Baccharis halimifolia (Compositae). Oecologia 83: 182-190.
22. Krischik, VA and RF Denno. 1990. Differences in environmental response of the sexes of the dioecious shrub Baccharis halimifolia (Compositae). Oecologia 83: 176-181.
23. Barbosa, P and VA Krischik. 1989. Correlated life history traits in some flightless female Lepidoptera of Eastern forests. Amer. Midland Natur. 122: 262-274.
24. Tallamy, DW and VA Krischik. 1988. Insect-plant interactions or reactions? Evidence from the Cucurbit System. Amer. Natur. 133: 766-786.
25. Krischik, VA, E McCloud, and J Davidson. 1988. Selection by vertebrate frugivores of green cecidomyiid-infested hollyberries (Diptera: Cecidomyiidae). Amer. Midland Natur. 121: 354-358.
26. Krischik, VA, P Barbosa, and CF Reichelderfer. 1988. Three trophic level interactions: The effects of dietary nicotine on a herbivore and an entomogenous bacterium. Environ. Entomol. 17: 476-482.
27. Goth, R, VA Krischik, and P Barbosa. 1987. Interactions among plant allelochemicals, plant pathogens, and insect herbivores. Phytopath. 77: 986.
28. Barbosa, P and VA Krischik. 1987. The influence of alkaloids on feeding preference and suitability of forest trees to the gypsy moth, Lymantria dispar (Lymantridae). Amer. Natur. 130: 53-69.
29. Krischik, VA and PG Weber. 1974. Induced parental care in male cichild fish. Developmental Psychobiology 8: 1-11.
Krischik, V and J Davidson. 2004. IPM of Midwest landscapes. MN Agr. Exp Station, 316 pp
Barbosa, P., V. Krischik, and C. Jones. 1991. Microbial mediation of plant insect interactions, John Willey and Sons, NY, 514 pp.
Krischik, V. and D. Galliart. 1991. Grain Insect Pest Management, USDA AMS, 145 pp.
2021- 2017 Recent extension bulletins
2021 Japanese Beetle Management, Dr. Vera Krischik, Entomology Extension Specialist, University of Minnesota and Doree Maser, MDA.
2021 Managing Turf Insects in Turf and Bee Lawns. Dr. Vera Krischik, Entomology Extension Specialist, University of Minnesota.
2020 Guide to Integrated Pest Management (IPM), Dr. Vera Krischik Entomology Extension Specialist, University of Minnesota and Laurie Schneider
2020 Conservation Guide: Pollinators, Plants, Pesticides, Dr. Vera Krischik, Entomology Extension Specialist, University of Minnesota and Laurie Schneider and Emily Tenczar,
2020 Understanding Pesticide Toxicity to Pollinators, Dr. Vera Krischik, Entomology Extension Specialist, University of Minnesota.
2020 Best Practices for Pollinators: Conserving Biodiversity in Open Spaces, Dr. Vera Krischik, Entomology Extension Specialist, University of Minnesota.
2020 Backyard Best Practices for Pollinators, Dr. Vera Krischik, Entomology Extension Specialist, University of Minnesota.
2020 Butterfly Gardening, Dr. Vera Krischik, Entomology Extension Specialist, University of Minnesota and Laurie Schneider.
2020 Pollinator Lawn IPM how-to instructions, Dr. Vera Krischik, Entomology Extension Specialist, University of Minnesota and Laurie Schneider.
2020 Conserving the Rusty Patched Bumble Bee, Dr. Vera Krischik Entomology Extension Specialist, University of Minnesota.
2000 Native Plants for Sustainable Landscapes: establishment and management of lakeshores and gardens, Dr. Vera Krischik, Entomology Extension Specialist, University of Minnesota, Catherine Reed, Serena Wiley.
2000 Native Shoreline Vegetation Poster, Dr. Vera Krischik, Entomology Extension Specialist, University of Minnesota.
2020 THINK IPM color poster, Dr. Vera Krischik, Entomology Extension Specialist, University of Minnesota and Laurie Schneider.
2017 Save the Bees Plant Flowers and Trees poster, Dr. Vera Krischik, Entomology Extension Specialist, University of Minnesota.
Select Extension Publications
Krischik, Vera A. 2015. Using degree days, IRA numbers, and new online bulletins. Minnesota Christmas Tree Growers March.
Krischik, Vera A. 2015. New federal, EPA and Minnesota labelling laws for protecting pollinator, MNLA Scoop Newsletter, 4 pp.
Krischik, Vera A. 2015. Leatherjackets and mole crickets in turf. Hole Notes Magazine, MN Golf Course Superintendents Association
Krischik, Vera A. 2014. Turf insecticides. MTGF Clippings Magazine, MN Turf and Grounds Foundation, Fall July 2014
Krischik, Vera A. 2014. Protecting bees and beneficial insects. Hole Notes Magazine, MN Golf Course Superintendents Association. Sept
Krischik, Vera A. 2014. Suppressing nuisance ants in turf. Hole Notes Magazine, MN Golf Course Superintendents Association. June
Krischik, Vera A. 2014. White grub management in turf. Hole Notes Magazine, MN Golf Course Superintendents Association. May
Krischik, Vera A. 2014. What is new in Christmas Tree IPM ground covers, Minnesota Christmas Tree Growers. October
Krischik, Vera A. 2014. How to practice IPM in managing beneficial insect and pest insects in Fraser Firs, Minnesota Christmas Tree Growers May
Krischik, Vera A. 2014. Protecting bees and beneficial insects from systemic insecticides applied in landscapes bulletin.
Krischik, Vera A. 2014. New turf insecticides and IRAC classifications bulletin.
Krischik, Vera A. and E. Tenczar. 2014. Pollinator conservation bulletin.
Krischik, Vera A. 2014. Insecticides used in greenhouse and landscapes and toxicity to pollinators bulletin
Krischik, Vera A. and E. Tenczar. 2014. Save the Bees poster (2.5 M PDF)
Krischik, Vera. 2013. Butterfly Gardening
Krischik Vera and Doree Maser. 2011. UM MDA Japanese Beetle Management in Minnesota
Krischik, Vera. 2010. Restoring shoreland with native vegetation poster.
Krischik Vera, Catherine C. Reed, and Serena E. Willey 2005. Native Plants for Sustainable Landscapes
Krischik Vera and Kathryn J. Bevacqua. 2005. Sustainability in Urban Ecosystems
Krischik Vera and Jeffrey D. Hahn. 2003. Insecticide Suggestions to Manage Landscape Tree and Shrub Insects
Krischik Vera and Mark E. Ascerno. 2000. Managing Lawn and Turf Insects
Hahn Jeff, Vera A. Krischik, and Steven J. Seybold. 2000. Forest Tent Caterpillars in Minnesota
Kyhl John, Mary H. Meyer, and Vera A. Krischik 1998. Establishing and Maintaining a Prairie Garden
Wawrzynski Robert, Vera A. Krischik, and Steve Katovich. 1997. The Bronze Birch Borer and Its Management
Krischik Vera, Kathryn J. Bevacqua, and Anne Hanchek. 1997. Selecting Hardy Roses for Northern Climates
Stroom Kevin, Jody Fetzer, and Vera A. Krischik. 1997. Insect Pests of Roses
Vera A. Krischik, Raymond M. Newman, and John F. Kyhl. 1997. Managing Aquatic Plants in Minnesota Lakes
- 2022-2025 Dr. Carrie Deans
- 2018-2019 Dr. Rebeca Guiteres Morano, current job Pollinator Coordinator with MN Board of Soils and Water
- 2007-2008 Dr. Garima Gupta, current job, researcher, Department of Zoology, Panjab University, Chandigarh, India
- 20017-20019 Temo Balaxashvili, European Georgia
- 2017-2018 George Kostakis, Greece
- 2010 Silas Martins and 2 others, Brazil
- 2008 Craig Corbett, South African
- Jameson Scholer, 2013
- Mary Rogers, 2008
- Emily Tenczar, 2007
- Emory Matts, 2005
- Scott Smith, 2000
- Luis Martin, MAG 2005, co-advisor for research
- Alyson Landmark, MAG 2000, co-advisor for research
- Barb Gregerson, MAG 1999, co-advisor for research
- Marcus Zbinden, MLS 1997, co-advisor for research
UROP undergraduate students
- 2020 Meredith Pounds
- 2019 Michaela Sanford
- 2017 Elizabeth Braatz
- 2013 Tyler Obermoller
- 2012 Rafael de los Rios Bolton
- 2008 Darcy Abrams
- 2005 Emily Tenczar