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Pear Insecticide Efficacy

Insecticide efficacy is a tricky topic for pear psylla and spider mites. Early suppression is necessary, but season-long control is only possible if natural enemies are not disrupted. Therefore, “efficacy” is a combination of pest control and compatibility with natural enemies.

How to get control of psylla that will last? Avoid “disruptive” materials unless pressure is very high. Limit to two per season and prior to bloom.

Product Effect on Psylla Natural Enemies Recommendation

 

Particle Films Surround (kaolin)

Celite (diatomaceous earth)

Adult Repellency – *key product Safe, but can flare spider mites if more than three sprays after bloom 50lb/acre 3 times:

1. early as possible, mid-late march

2. popcorn

3. 1000DD (about 14 days after petal fall)

Cocoon (kaolin)

Microna (calcium carbonate)

Less effective than Surround and Celite Safe, but can flare spider mites if more than three sprays after bloom. Microna flares rust mites. * don’t use for psylla, doesn’t work as well and is not legal.

 

IPM Insecticides AzaDirect/Neemix Nymph suppression Very Safe High pressure organic: once per week for 3 weeks when young nymphs are present. Start near bloom (600DD), again early/mid-June (1500DD)

Low pressure organic: same start times with 1 follow up spray

Cinnerate Psylla adult knockdown

Nymph mortality

Very Safe Use high rate with 1st and 3rd Surround or Celite sprays to target adults

(see Surround and Celite timings above)

Esteem Adult sterilizer Safe 2 sprays: 1. Just before Budburst, 2. Popcorn (2 weeks after first spray)
Centaur Nymph suppression Safe Popcorn or 1000 DD (about 14 days after petal fall)
Ultor Nymph suppression Safe 2 sprays: 1. 1000DD (about 14 days after petal fall), 2. 1400DD (about 1 month after petal fall)

 

Disruptive Malathion Adult mortality – Good, short residual Highly disruptive Do not use unless pressure is very high. Use once at most.

Spray just before budburst.

Bexar All psylla life stages – Good Disruptive Do not use unless pressure is high. Limit to one use.

Spray at popcorn.

Assail All psylla life stages – Good Disruptive Do not use unless pressure is high. If needed, limit to one use.

Spray at popcorn.

Actara Psylla Nymphs – Good Disruptive Unnecessary
Rimon Psylla eggs & nymphs – okay Disruptive Unnecessary
Warrior (lambda-cy) Not effective Highly disruptive Stop using this, please.

 

 

Other pest IPM plans:

Codling moth Gen 1 Gen 2 Gen 3
Bloom – Mating Disruption 375 CMDD – Oil 525 CMDD – Altacor 1400 CMDD – oil intrepid 1550 CMDD – Dimilin Early Aug- Altacor

 

Spider- and Rust Mites: 1. Lime sulfur at delayed dormant. 2. Follow IPM sprays for psylla and Codling moth. 3. Sample, if mites approach injury level use Nealta or Envidor, (Cinnerate, TetraCURB, or other essential oil based product if organic)

 

Contact

Louis Nottingham
Assistant Professor, Entomology
Washington State University
Tree Fruit Research & Extension Center
1100 N Western Ave., Wenatchee, WA 98801
540-798-2044 (cell)

Washington State University