Miticides options for controlling mites in cherry

Many options are available for mite control in Michigan cherries.

Mite populations at the Northwest Michigan Horticulture Research Center remain low at this time, but we have received reports that mite numbers are building in orchards in the region. With a relatively drier season, 2016 poses the potential for higher than normal pest mite densities. Furthermore, insecticides targeting the complex of late season pests, particularly pyrethroids for spotted wing Drosophila (SWD) control, could contribute to mite flaring; growers should be prepared for the possibility that orchards may need a miticide this season.

Pyrethroid insecticides are toxic to mite predators, and their use can lead to a flare up of pest mites. Fortunately, there are several registered miticides available for use on cherries (Table 1). However, growers should check labels for pre-harvest intervals and registered uses if a miticide is applied before or after harvest. Please refer to the “2016 Fruit Management Guide” by Michigan State University Extension for additional information on miticide efficacy.

Scouting for mites should begin prior to harvest with enough time to determine if a miticide will be needed prior to harvest. This pre-harvest monitoring period should begin early enough to consider that some miticides have a long pre-harvest interval. One method of monitoring twospotted spider mite motile populations consists of sampling 25 intermediate-aged leaves at three to five sites within a block. Count the number of leaves that have two or more twospotted spider mite motiles from each sample, and follow the binomial charts to estimate the number of mites per leaf (Tables 2-3). Treatment thresholds for twospotted spider mites are eight to 10 mites per leaf from July through post-harvest.

Table 1. Miticides to use on cherry crops to target certain mite pests

Compound

PHI cherry

Life stage target

Life stage target

Seasonal timing

Residual control

Savey

28

 

European red mite

Egg/larvae

Early***

8-12 weeks

Twospotted spider mite

Egg/larvae

Mid (or threshold)**

6-8 weeks)

Onager

28

Twospotted spider mite

Egg/larvae

Mid (or threshold)**

6-8 weeks

Apollo

21

European red mite

Egg/larvae

Early***

8-12 weeks

Twospotted spider mite

Egg/larvae

Mid (or threshold)

6-8 weeks

Agri-Mek

21

European red mite, Red mite

Motiles*

Early****

8-12 weeks

Twospotted spider mite

Motiles*

Mid (or threshold)

6-8 weeks

Gladiator

21

European red mite, Red mite

Motiles*

Early****

8-12 weeks

Twospotted spider mite

Motiles*

Mid (or threshold)

6-8 weeks

Vendex

14

European red mite

Motiles*

Mid (or threshold)**

4-6 weeks

Twospotted spider mite

Motiles*

Mid (or threshold)

4-6 weeks

Zeal

7

European red mite

Egg/larvae

Early (or threshold)**

8-10 weeks

Twospotted spider mite

Egg/larvae

Mid (or threshold)**

6-8 weeks

Envidor

7

Twospotted spider mite

Egg, motiles*

Mid (or threshold)

6-8 weeks

Nexter

300

European red mite, Red mite, Twospotted spider mite

Motiles*

Mid (or threshold)**

6-8 weeks

Acramite

3

European red mite

Motiles*

Mid (or threshold)**

6-8 weeks

Twospotted spider mite

Motiles*

Mid (or threshold)

6-8 weeks

Danitol

3

European red mite

Motiles*

Mid (or threshold)**

4-6 weeks

Twospotted spider mite

Motiles*

Mid (or threshold)

4-6 weeks

Magister

3

Twospotted spider mite

Eggs, motiles*

Mid (or threshold)

3-5 weeks

(Table modified from “Miticides options for controlling mites in fruit” by John Wise, Rufus Isaacs, Larry Gut published on April 26, 2016).
* Motile forms include mite larvae, nymph and adult stages.
** Optimally used petal fall through August when mites reach threshold.
*** Optimally used pre-bloom through first cover.
**** Optimally used petal fall through second cover.

Table 2. Binomial sampling chart for twospotted spider mites

# of leaves with two or more mites

% of leaves with two or more mites

Avg. # mites per leaf

10

40

2.1

12

50

3.0

15

60

4.1

17

70

5.4

20

80

8.5

21

84

10.1

* Examine 25 leaves per site at each of three to five site per block.
* Charts are adapted from “Orchard Pest Management” published by Good Fruit Grower, 1993.

Table 3. Binomial sampling chart for European red mites

# of leaves with two or more mites

% of leaves with two or more mites

Avg. # mites per leaf

10

40

0.7

12

50

1.1

15

60

1.6

17

70

2.6

20

80

4.7

22

90

11.4

20

95

15.3

* Examine 25 leaves per site at each of three to five site per block.
* Charts are adapted from “Orchard Pest Management” published by Good Fruit Grower, 1993.

Dr. Rothwell’s work is funded in part by MSU’s AgBioResearch.

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