Maple Spider Mites - Nursery IPM

**Maple Spider Mites (Acer rubrum)**

Overwinter in bark crevices as adults and eggs
Some also seek refuge under dead armored scale insects
Migrate to the underside of the leaves in the spring
Adults are 0.25-1mm in length, multiple hairs along their back, and
reddish brown in color
Eggs are spherical, and red to clear in color
- Found in bark crevices, along leaf veins, or near branch buds
Larvae have six legs, adults have eight
Larvae and nymphs have lighter colorations or a green hue
Have needle-like mouthparts that rupture plant cells
- Feeds on cell mesophyll
Multiple years of damage can reduce plant vigor and growth
Damage increases in hot weather
2-3 weeks to complete one generation, and many generations
occur per season
Causes brown flecking or stippling of the foliage
Entire leaves can become yellow, silver, or bronzed
Host plants: maple trees (Acer spp.), particularly red maples
- (Acer rubrum) and Freeman maples (Acer x freemanii)

Natural predators: lady beetles, thrips, predatory mites, lacewing larvae, minute pirate bugs
Cultivate an environment that attracts natural predators
- Diverse flowers, water sources
Scout in the spring
- Spider mites are small, slowly moving, brown or black dots
- Predatory mites are fast moving
- Scout on susceptible cultivars or trees that were the most damaged the previous year
Reduce plant stress
- Proper planting, spacing, and water
- Avoid excessive nitrogen fertilization
Do not spray carbaryl (aphrodisiac)

Contact insecticides:
- Pyrethroids [3]: –thrins
Systemic insecticides:
- Avermectins [6]: abamectin
- Acephate (translaminar)
- Bifenazate [20D] (reduced risk)
- Acequinocyl [20B] (reduced risk)
Considerations:
- May harm non-target species