Many materials available for pear psylla management

Michael Haas, and Larry Gut, Michigan State University Extension, Department of Entomology - March 15, 2012

With high temperatures expected this week, Michigan pear producers should start managing for psylla by applying a dormant oil application with or without insecticide.

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

Michigan pear producers know that management of pear psylla presents a challenge each season. Psylla become active early and numbers can quickly grow to unacceptable levels. Also, the ability of this pest to rapidly develop insecticide resistance makes it especially important to carefully consider each material included in a management plan. A dormant oil application is a good start to a program that alternates materials with different modes of action (MOA) as needed throughout the remainder of the season. Given the temperatures expected this week, it would be a good time to start managing for psylla by applying a dormant oil application with or without insecticide.

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

Materials that share the same MOA group number have the same mode of action even if the number is 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. Do not underestimate the power of natural enemies in the management of pear psylla. An orchard of Bartlett pears at the Trevor Nichols Research Center in Fennville, Mich., unmanaged for psylla, has had no sign of psylla for the last several years.

Check the current “Michigan Fruit Management Guide” (E-154) for information on the effectiveness of many of the control options listed in the table.

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	lambda-cyhalothrin	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).