Spider Mites

Characteristics

Spider mites are a type of mite closely related to spiders and other arachnids. They have silk glands in a part of their mouths that they use to produce mats of webbing on foliage. They go through 5 stages before they become an adult: egg, six-legged larva, protonymph, deutonymph and finally an adult stage. Mites hatch from an egg and grow into an adult in about 5-20 days.

Spider mites are less than 1.3 millimetres long and look like tiny dots on trees and shrubs. Mites use a pair of needle like mouthparts, to rupture the cells of leaves or needles. They use their mouths to suck out fluids from foliage.

A common species of spider mite - the spruce spider mite-  will attack coniferous trees, especially the dwarf Alberta spruce. Unlike other mites, it prefers cooler temperatures in early spring and late fall.

Signs & Symptoms

Spider mites will leave small yellow spots on the leaves and branches, and cause curling branches. In widespread infestations, masses of webs will be visible on the foliage of leaves and needles. On coniferous trees, needles will turn yellow - brown, and eventually fall off.

Treatment & Recommendations

A dormant oil application in early spring is the best way to help control the population of spider mites. Pruning trees to remove dead branches and allow for better airflow through branches can help reduce mite populations. Healthy trees with adequate growing conditions will be less prone to mite problems.

If your tree appears to be suffering from mite problems give our office a call. One of our qualified arborists will provide you with information on how to keep your tree healthy.