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.