Wood Acres Tree Specialists MD, DC, VA
call for tree service-1-888-464-3926
10315 Kensington Parkway, Kensington MD 20895-3358
Leaf Notes Blog
Tree & shrub care services
General Tree Work:
Plant Health Care:

Spruce Spider Mite

USDA Forest Service - Region 4 - Intermountain Archive, USDA Forest Service, Bugwood.org
[Oligonychus ununguis (Jacobi)] has the broadest host range of any spider mite that feeds on conifers. Hemlocks, arborvitae, Juniperus spp., and others are affected. Symptoms of spruce spider mites feeding vary, but usually cause either bleaching/stippled yellowing/whitening at needle bases (arborvitae or hemlock) and/or bronzing/needle drop/webbing (spruce or fir).

The tiny eggs are orange with ridges and have a “thread” coming off the top called a stipe. This “orange-bomb” shape distinguishes them from other spider mites. Eggs hatch 5-10 days after being laid and it takes ~2 weeks for SSM to go through several green/orange nymphal stages and finally molt into the green/yellow-orange adult stage. This entire life-cycle may take only 12-19 days in optimum conditions.
Misinformation persists around the seasonal biology of SSM. Several (5+) generations occur per year, depending upon temperature. SSM is a cool-season species. Temperatures above 85F halt their development. With the current temperatures and dry weather, SSM is poised to resume activity after its summer “sleeping” phase. It is possible to see the highest yearly populations of SSM from September to November.

Miticides are often needed when predators are not abundant.
Pro-active tree & shrub care
Insect & Tree Pest Index Tree & Shrub Disease Index Tree & Shrub Damage Index Monthly Plant Health Care Report
Tree & Shrub Care info
Maryland Aborist Association   Tree Care Association Accreditation   ISA Certified Master Arborist ISA Certified Arborist
Maryland Arborist
Tree Care Industry
International Society
of Arboriculture
Master Arboist
On Staff
Copyright © 2010-2017 Wood Acres Tree Specialists - All Rights Reserved