Pear psylla management arsenal gets bigger

Michael Haas, and Larry Gut, Michigan State University Extension - April 01, 2008

Entomology and Trevor Nichols Research Complex

If you didn’t get the results you expected from your pear psylla management program last year you aren’t alone. Insecticide resistance is common in psylla throughout the pear-growing areas of the world. These insects spend most of their time within pear orchards and can be exposed to repeated applications of the same handful of insecticides unless attention is given to rotation among chemical classes. The good news is that growers now have many choices for control options, making it easier to avoid treating successive generations with the same material or with materials that have the same modes of action.

Table 1 contains products that are labeled for psylla control in pears in Michigan. Listed for each table entry are the mode of action (MOA) group number as assigned by the Insecticide Resistance Action Committee, common name, trade name and insecticide class.

Materials that share the same number have the same mode of action even if followed by a different letter. For example, carbaryl has an MOA classification of 1A and diazinon of 1B. The number 1 indicates that both materials share the same MOA, in this case they are both cholinesterase inhibitors. The letter after the number represents the chemical sub-group. Notice that the last six table entries have no MOA classification and can be applied whenever appropriate for that material. A sound resistance management program relies on treating successive generations of psylla with materials from different MOA groups. Read the label directions for complete information regarding application rates, timing, combination with adjuvants and precautionary statements regarding effects on natural enemies and bees. Check the 2008 Michigan Fruit Management Guide for information on the effectiveness of many of the control options. Call the MSUE Bulletin office at 517-353-6740 to order a copy.

Pear psylla. Photo credit: J. Dykinga, USDA-ARS

Table 1. Insecticides labeled for pear psylla control in Michigan

MOA Group1	Common name	Trade name	Insecticide class
1A	carbaryl	Sevin	carbamate
1B	azinphosmethyl	Azinphos-methyl,	organophosphate
1B	chlorpyrifos	Chlorpyrifos, Govern, Lorsban, Nufos, Warhawk, Whirlwind, Yuma	organophosphate
1B	diazinon	Diazinon	organophosphate
1B	dimethoate	Dimate	organophosphate
1B	methidathion	Supracide	organophosphate
2A	endosulfan	Endosulfan, Thionex	organochloride
3	deltamethrin	Battalion, Delta Gold, Decis	pyrethroid
3	esfenvalerate	Asana XL, Adjourn	pyrethroid
3	fenpropathrin	Danitol	pyrethroid
3	gamma-cyhalothrin	Proaxis	pyrethroid
3	lambdacyhalothrin	Silencer, Warrior	pyrethroid
3	permethrin	Ambush, Arctic, Pounce, Perm-Up, Permethrin	pyrethroid
3	zeta-cypermethrin	Mustang Max	pyrethroid
3	pyrethrins	Pyganic	pyrethrin
3, 27A	pyrethrin + piperonyl butoxide	Evergreen	pyrethrin
4A	acetamiprid	Assail	neonicotinoid
4A	clothianidin	Clutch	neonicotinoid
4A	imidacloprid	Couraze, Pasada, Provado, Impulse, Nuprid, Prey	neonicotinoid
4A	thiacloprid	Calypso	neonicotinoid
4A	thiamethoxam	Actara	neonicitinoid
5	spinetoram	Delegate	spinosyn
6	abamectin	Abacus, Abba, Agri-Mek, Epi-Mek, Reaper, Zoro	antibiotic
6	emamectin benzoate	Proclaim	avermectin
7C	pyriproxifen	Esteem	insect growth regulator
15	diflubenzuron	Dimilin	benzoylurea
16	buprofezin	Centaur	insect growth regulator
18B	azadirachtin	Aza-Direct, Ecozin, Neemix	botanical
21	fenpyroximate	FujiMite, Portal	phenoxypyrazole
21	pyridaben	Nexter	pyridazinone
	sulfur	Golden-Dew, Kumulus DF, Micro Sulf, Microthiol Disperss, Sulfur-DF
	horticultural oil	horticultural oil
	calcium polysulfides	Rex Lime Sulfur Solution, Sulforix
	kaolin clay	Surround	particle film
	oil, paraffinic	Citrus oil, JMS Stylet-oil
	potassium salts of fatty acids	M-Pede

1 mode of action classification

This article was published by Michigan State University Extension. For more information, visit https://extension.msu.edu. To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464).