Proactive Insecticide Resistance Monitoring and Management for Crucifer Flea Beetle

1. Proactive Insecticide Resistance Monitoring and Management for Crucifer Flea Beetle • Investigators: • Janet Knodel, NDSU • Daniel Waldstein, BASF, CA • Patrick Beauzay, NDSU

2. Flea Beetles of Canola Crucifer Flea Beetle Phyllotretacruciferae Striped Flea Beetle Phyllotreta striolata

3. Canola seedling damage, pitting, caused by flea beetle feeding (top) and undamaged seedling (bottom). Insecticide Seed Treatment Effective

4. Source: Pesticide Use and Pest Management Practices in North Dakota – 1996, 2000, 2004, 2008

5. Background • Neonicotinoid insecticidal seed treatments • >10 years • Insecticide resistance • Widespread adoption of one insecticide class used year after year against an abundant pest • Tansy et al. 2008 J. Econ. Entomol. 101: 159-167. • Differences in Phyllotretacruciferaeand Phyllotretastriolata ((Coleoptera: Chrysomellidae) Response to Neonicotinoid Seed Treatments • P. crucifereaehigher mortality than P. striolataon neonicotinoid ST (thiamethoxam & clothianidin) • Overwintering flea beetles (May) more susceptible than summer flea beetles (August) • Species shift from P. cruciferaeto P. striolata

7. Julie Soroko’s Flea Beetle Survey 2010Flea Beetle Species Composition in ND • Eight species total • Phyllotretacruciferae • 87% of sites as main flea beetle species • Chaetocnema species • 13% of sites • P. striolatalower than P. crucifereaeand Chaetocnema species • Hop flea beetle (Psylliodespunctulata) • Low numbers at 39% of sites

8. Maximum Numbers of Flea Beetles Found on Yellow Sticky Traps in Canola across ND in 2010 >10 flea beetles per trap per day 5-10 flea beetles per trap per day <5 flea beetles per trap per day 76% 13% 11%

9. Examples of Trapping Results

10. Objectives • To determine if registered neonicotinoid insecticide seed treatment on canola are currently as effective against the crucifer flea beetle (Phyllotretacruciferae) and stripped flea beetle (P. striolata) • To test a novel insecticide seed treatment (new mode of action) that is being developed for canola • Valuable tool in a resistance management program

11. Materials and Methods • ‘Spring’ flea beetle population (overwintering) • Used baited kairomone traps to capture flea beetles • 8 traps per field site • Renville, Cavalier, Foster Counties in ND and Roseau County in MN • Unable to capture enough flea beetles to conduct greenhouse bioassay • Early spring • Beetles emerged in early April 2012

12. Materials and Methods • Live flea beetles collected by sweep net from fields approximately 3 days after swathing • ‘Summer’ populations (new generation in August) • Renville, Bottineau, Cavalier, Griggs Counties in ND and Kittson County in MN • Approximately 2,500 beetles per location

13. Materials and Methods • Flea beetles kept in cages • Flea beetles fed fresh canola and organic kale every three days • Flea beetles removed from cages using an aspirator and then released in experimental pots

14. Materials and Methods • 15 P. cruciferae per pot (or 3 flea beetles per seedling) • 5 canola seedlings per pot • 5 locations, 4 replications, 4 treatments • 2 timings (7 and 14 DAP) • RCB design (reps = blocks)

15. Materials and Methods • Treatments • Untreated Check • Helix XTra - Thiamethoxam @ 400 gai per kg seed (IRAC Group 4A) • Prosper - Clothianidin @ 400 gai per kg seed (IRAC Group 4A) • Compound A (IRAC Group 28 - cyanthraniliprole) • Modulates the ryanodine receptor modulators • Affects Ca++ flow in insect cells

16. Materials and Methods • Live flea beetles counted and recorded for each pot at 1, 3, 7, 10 and 14 days after introduction (up to 10 days for the 14 DAP plants) • Corrected Mortality (Schneirder-Orelli, 1947) • M (%) = (t – c) / (100 – c) * 100 • t = percent mortality in treatments • c = percent mortality in controls (untreated checks) • Data analyzed using PROC GLIMMIX in SAS statistical software • Treatment means compared using Tukey’s HSD at α = 0.05

17. Results • Location effect and location x treatment effect not significant for 7 and 14 DAP test • Treatment effect significant for each test

18. b c c b c c c c c c b a b a a b b a a a

19. c c c c c c c c b b b b a a a a

20. 27% SFB 60% SFB 33% SFB

21. Conclusions • P. cruciferaeis still susceptible to the tested neonicotinoid ST in ND and NW MN • Difficult to find P. striolatato run efficacy tests • Limited data suggested that P. striolataexperienced lower mortality than P. cruciferae(MN site only) • Similar results to Canada (Tansy et al., 2008 & 2009) • New Mode of Action provided intermediate levels of mortality • Field efficacy in Langdon REC show similar damage ratings to Helix XTra

22. Acknowledgments • Trapping Cooperators • LoAyne Voigt, Renville County Extension Agent • Dave Grafstom, Roseau Regional Extension Office, MN • Bryan Hanson, Langdon REC • Northern Canola Growers Association

23. Aster Leafhoppers in 2012Macrostelesquadrilineatus • Migrate in ND in early May; may have overwintered in ND • Observed in wheat, barley, canola, potatoes, sunflowers • Vectors aster yellows • Delayed expression of 21-35 days or symptomless • No action threshold or insecticide treatments recommended • ND Aster leafhoppers - 25% infectivity rate (Source - Dr. Olivier, Saskatoon) Aster leafhopper adult. (Photo courtesy of W. Cranshaw, CSU, Bugwood.org)

24. AY symptoms on seeds Source: Dr. Chrystel Olivier, Agriculture and Agri-Food Canada Research Centre, Saskatoon. • 30-70% misshapen seeds in AY infected canola. • Germination: 0% for misshapen seeds; 50-90% for normal looking seeds. 1% infected plants production loss: 0.03% – 0.07% 5% infected plants production loss: 1.5% - 3.5% Healthy AY-infected Healthy

25. AY epidemiology There are correlations between % inf. plants, % inf. M. quadrilineatus and nb of leafhoppers early in the season. -Possibility of developing an early warning system. Source: Dr. Chrystel Olivier, Agriculture and Agri-Food Canada Research Centre, Saskatoon.