The New Zealand Institute for Plant & Food Research Limited 1. The updated IRM rotation strategy for DBM 2. Status of insecticide resistance in DBM 3. Issues with IPM for vegetable (heading) brassicas 4. Issues with IPM for head lettuce Presented by: Graham Walker (Plant & Food Research, Auckland)

The New Zealand Institute for Plant & Food Research Limited IPM programme for vegetable brassicas To ‘Advance IPM’, we need to: 1.Monitor the status of insecticide resistance in DBM 2.Incorporate NEW insecticides into the IRM rotation strategy 2000 version 2009 version (‘Ute guide’ & CD ROM)

The New Zealand Institute for Plant & Food Research Limited IRM Rotation Strategy for DBM (2001) (Walker et al. 2004: 80% uptake)

The New Zealand Institute for Plant & Food Research Limited Resistance ratios for lambda-cyhalothrin & methamidophos (compared with susceptible laboratory colony, Walker et al. 2011) Resistance to synthetic pyrethroids is very high and increasing. Resistance to methamidophos has decreased.

The New Zealand Institute for Plant & Food Research Limited Resistance ratios for lambda-cyhalothrin & methamidophos (compared with susceptible laboratory colony, Walker et al. 2011) Resistance to synthetic pyrethroids is very high and increasing. Resistance to methamidophos has decreased.

The New Zealand Institute for Plant & Food Research Limited Resistance ratios for spinosad & indoxacarb (compared with susceptible laboratory colony, Walker et al. 2011) No resistance in DBM (10x) May be some tolerance to indoxacarb?

The New Zealand Institute for Plant & Food Research Limited Why was the DBM IRM strategy updated? 1.Updated information on the resistance of DBM in New Zealand 2.Pre-transplant drenches became available 3.Overseas, DBM has quickly become resistant to NEW insecticides  Including the NEW ‘diamides’ (IRAC group 28) We need to ensure ‘diamides’ are not used all year round:  Diamides registered in New Zealand as a foliar spray and a drench:  Coragen® (chlorantraniliprole)  Durivo™ = chlorantraniliprole and thiamethoxam (a neonicitinoid) MAIN PROBLEM: how to fit ‘pre-transplant drenches’ into an IRM strategy that previously included only foliar sprays?

The New Zealand Institute for Plant & Food Research Limited DBM IRM rotation strategy (updated March 2012)

The New Zealand Institute for Plant & Food Research Limited Summary of updated IRM strategy 1.“Window” approach is for regional coordination  avoid exposure of consecutive generations to the same MoA 2.neonicitinoid drenches have also been put in a “window”  to minimise aphid resistance  Aphicides (pymetrozine & pirimicarb) also separated 3.spinosad and indoxacarb have been transposed  for later use of spinosad for control of thrips 4.synthetic pyrethroids in the late window (not effective on DBM) 5.organophosphates not placed in a specific window:  as a ‘break group’ from other MoA groups  for establishment pests and clean-up at harvest All growers need to conform to this IRM strategy: = “ROTATE different MoA insecticides”

The New Zealand Institute for Plant & Food Research Limited Status of insecticide resistance in DBM Assays undertaken this year  using different doses of each product comparing mortality of field populations with susceptible laboratory strain Populations collected from Pukekohe RS, Levin and Lincoln Tested all populations against Karate Zeon® Also some testing against Coragen® and Steward® RESULTS: Very high resistance to Karate® Zeon in all regions No resistance to Coragen at Pukekohe No resistance to Steward at Levin CONCLUSION: Synthetic pyrethroids are not effective against DBM

The New Zealand Institute for Plant & Food Research Limited SUMMARY: Update on IPM for heading brassicas No resistance in DBM to ‘new’ insecticides IRM strategy is more complicated? Is it okay? We need to protect the diamides (IPM compatible)  Chlorantraniliprole (Coragen and Durivo)  Cyantraniliprole (Exirel in forage brassicas) Other issues: Phase-out of organophosphates (OPs): = a challenge (fewer MoAs, issues with control of secondary pests) BUT also an opportunity to ADVANCE IPM At least: scout crops and ROTATE different MoAs!! Also: Establishment of GWB in New Zealand will probably lead to an increase in use of foliar larvicides

The New Zealand Institute for Plant & Food Research Limited Update on IPM for head lettuce Main insect pests are still: 1.Onion thrips (after onions are harvested) 2.Soybean looper and Helicoverpa late season? »Helicoverpa is dangerous (1 medium-sized larva can destroy a head) 3.Aphids? Issues: Over-dependence on drenches  neonicitinoids for aphids, Durivo on leafy greens? Care needed to protect the neonicitinoids and the diamides from insecticide resistance = use IPM! 1.Monitor (scout) crops 2.Minimise insecticides 3.ROTATE different MoA insecticides 4.Use selective insecticides early »Insect predators can control all small insects

The New Zealand Institute for Plant & Food Research Limited Acknowledgements Vegetables NZ Vegetable growers Various MPI SFF projects: nos. 04/055, 07/017, 08/050 Various researchers and collaborators

The New Zealand Institute for Plant & Food Research Limited Thank you! DBM IRM strategy: “flyer” to vegetable brassica growers Also in: New Zealand Grower Vol. 67 (6): 56-59