Scouting: Spider mites are easy to monitor despite their small size. Shake plants vigorously over a pail or bucket and then look for the tiny moving dots; they look like specs of sand walking around in the bottom of your pail. Initial infestations can be spotty, so it is important to check several places near the edge of the field. Spider mites are often found in potatoes near dusty roads or mite-harboring crops like alfalfa, corn, mint, or wheat.
Control: In many cases, a single, well-timed application will control spider mites. If you can see webbing on the leaves and bronzing or stippling from mite feeding, then it may be too late to get effective control with one application. Most miticide products target eggs and immature stages.
Photos
A two-spotted spider mite adult with eggs (photo by Andy Jensen, NW Potato Research Consortium).
Leaves without and with stippling caused by spider mite feeding (photo by Carrie Wohleb, WSU).
Stippling and gray fuzzy spider mite webbing (photo by Andy Jensen, NW Potato Research Consortium).
Control Options for Two-spotted Spider Mite on Potatoes
| Material | Application per Acre | REI | PHI | MOA | Eff. | Notes |
|---|---|---|---|---|---|---|
|
abamectin + cyantraniprole (Minecto Pro) |
5.5 to 10 fl oz | 12 h | 14 d | 6, 28 | G-F | Apply when mites first appear. Repeat the application after 7+ days if needed to maintain control. |
|
abamectin (Agri-Mek SC) |
1.75-3.5 fl oz | 12 h | 14 d | 6 | G-F | Apply when mites are first detected. |
|
bifenazate (Acramite 4SC) |
16 to 24 fl oz | 12 h | 14 d | 20 | E-G | Apply when spider mites are present. |
|
fenpyroximate (Miteus) |
2 pt | 12 h | 7 d | 21A | E | Apply before mite populations begin to build. Controls all life stages, also stops feeding and egg laying. |
|
hexythiazox (Onager, Onager Optek) |
16 to 24 fl oz | 12 h | 21 d | 10A | G | Apply at the first sign of mites i.e., apply early in the outbreak cycle. Controls mites via activity on eggs and immatures; it will not control adults, but they won’t lay viable eggs. |
|
mineral oil/petroleum distillate (BioCover MLT) |
See Label | 4 h | - | NC | ND | Apply when spider mites first appear. |
|
neem oil (Trilogy) |
See Label | 4 h | 0 d | NC | ND | Apply when mites first appear. |
|
proparagite (Comite) |
32 to 40 fl oz | 2 d | 14 d | 12C | G | Apply when spider mites are present. Comite has a REI of 2 days, which is long compared to other miticides. |
|
spiromesifen (Oberon 4SC) |
4-8 oz | 12 h | 7 d | 23 | E-G | Apply at the first sign of mites before adult populations build up. Controls all mite stages, but juveniles are more susceptible. |
|
spirotetramat (Movento HL) |
2.0-2.5 fl oz | 24 h | 7 d | 23 | F | Movento HL is not recommended as a rescue treatment for spider mites, but it may delay or prevent mite outbreaks when it’s applied to control other pests. Do not apply after Oberon (another Group 23) unless an application of an insecticide with a different mode of action is used first. |
| Material | Application per Acre | REI | PHI | MOA | Eff. | Notes |
|---|---|---|---|---|---|---|
|
abamectin + cyantraniprole (Minecto Pro) |
5.5 to 10 fl oz | 12 h | 14 d | 6, 28 | G-F | Apply when mites first appear. Repeat the application after 7+ days if needed to maintain control. |
|
abamectin (Agri-Mek SC) |
1.75-3.5 fl oz | 12 h | 14 d | 6 | G-F | Apply when mites are first detected. |
|
bifenazate (Acramite 4SC) |
16 to 24 fl oz | 12 h | 14 d | 20 | E-G | Apply when spider mites are present. |
|
fenpyroximate (Miteus) |
2 pt | 12 h | 7 d | 21A | E | Apply before mite populations begin to build. Controls all life stages, also stops feeding and egg laying. |
|
hexythiazox (Onager, Onager Optek) |
16 to 24 fl oz | 12 h | 21 d | 10A | G | Apply at the first sign of mites i.e., apply early in the outbreak cycle. Controls mites via activity on eggs and immatures; it will not control adults, but they won’t lay viable eggs. |
|
mineral oil/petroleum distillate (BioCover MLT) |
See Label | 4 h | - | NC | ND | Apply when spider mites first appear. |
|
neem oil (Trilogy) |
See Label | 4 h | 0 d | NC | ND | Apply when mites first appear. |
|
proparagite (Comite) |
32 to 40 fl oz | 2 d | 14 d | 12C | G | Apply when spider mites are present. Comite has a REI of 2 days, which is long compared to other miticides. |
|
spiromesifen (Oberon 4SC) |
4-8 oz | 12 h | 7 d | 23 | E-G | Apply at the first sign of mites before adult populations build up. Controls all mite stages, but juveniles are more susceptible. |