Yes, spider mites over winter by going into a sleep-like state called diapause that lets them survive cold months. Most species don't die off when frost hits. They find a hiding spot, shut down their bodies, and wait for warm weather to come back. Different species use different tricks to make it through, but the end result is the same. Your mite problem from last year can come right back in spring.
I found this out while pruning my apple trees one January. I peeled back a strip of loose bark and saw a cluster of tiny orange-red dots tucked into the crevice. Those were dormant female twospotted spider mites waiting for spring. That moment explained why the same trees got infested year after year. The mites had been hiding on the tree the whole time, right under my nose.
Spider mite diapause kicks in when days get shorter and temps start dropping in fall. Adult females stop laying eggs and enter a dormant state. Many species change color from green or yellow to a bright orange-red during this shift. Suzuki's 2012 research showed that artificial light can disrupt diapause. That's why your indoor plants don't get a break from mites in winter.
Each species hides in a different spot. Twospotted spider mites hide as dormant females in bark cracks and leaf litter. European red mites take a different path. They overwinter as tiny red egg spheres glued to twigs and branches where you can spot them if you look close. Spruce spider mites lay their eggs right on the needles of your evergreen trees.
Twospotted Spider Mites
- Hiding spots: Dormant females tuck into bark crevices, fallen leaf litter, and the top inch of garden soil around your plants.
- What to look for: Tiny orange-red dots in clusters of 5 to 20 on rough bark or under fallen leaves near host plants.
- Winter action: Clean up leaf litter in fall and inspect bark during pruning to find and remove dormant colonies.
European Red Mites
- Hiding spots: Overwinter as round red eggs glued to twigs and small branches on fruit trees like apples and pears.
- What to look for: Shiny red spheres about the size of a pinhead, often grouped near buds and branch joints.
- Winter action: Apply dormant oil spray in late fall or early spring to smother eggs before they can hatch.
Spruce Spider Mites
- Hiding spots: Lay dark round eggs on the needles of spruce, juniper, and other evergreen trees throughout your yard.
- What to look for: Tiny dark eggs tucked at the base of needles, best seen with a 10X hand lens in winter.
- Winter action: A dormant oil spray on evergreens in early spring catches these eggs before spring hatch begins.
Finding overwintering spider mites gives you a chance to act before spring brings them back to life. Apply a dormant oil spray to your fruit trees and evergreens in late fall or early spring. The oil coats the eggs and dormant females and smothers them before they can wake up. This one treatment alone can cut your spring mite pressure by a huge amount and save you weeks of work later on.
Your fall cleanup matters more than you might think for managing overwintering spider mites in your yard. Rake up leaf litter where dormant females hide. Pull out old plant debris and toss it in the trash, not your compost pile. In my experience, checking bark crevices during winter pruning tells you how bad next spring could be. These steps take away the shelters mites need to survive the cold and give you a real head start on next year's pest control season.
Read the full article: Spider Mites: Full Guide to Control
