Spider Mites

Order/Family: Acari/Various

Description:

  • Mites are extremely small, typically no larger than 1/2-millimeter in diameter.
  • Mite adults and nymphs have eight legs; larvae (smallest) have six legs.
  • Boxwood mites: brownish yellow.
  • Southern red mites: purplish or reddish in color.
  • Spruce spider mite: grayish black with a tan area behind the mouthparts.
  • Two-spotted spider mite – greenish yellow with a black spot on each side of the body.

 

Biology and Habits:

  • Except for the two-spotted spier mite, eggs, which are similar in color to the adults, are the overwintering stage on leaves and small branches. Two-spotted spider mite adult females overwinter as adults in bark cracks.
  • All stages of the mite, except the egg, use their needle-like mouthparts to suck plant juices, causing tiny spots (stippling) particularly on the leaves.
  • There are several generations per year.

 

Plants Attacked:

  • Boxwood mite: common, English, and European boxwood.
  • Southern red mite: azalea, firethorn, holly, mountain laurel, rhododendron, rose, viburnum, and yew.
  • Spruce spider mite: arborvitae, hemlock, pine, and spruce.

 

Damage:

  • Spider mites cause small spots (stippling) on the leaves or needles. Heavy infestations can cause the leaves or needles to turn pale green to yellow and drop.
  • In heavy infestations, the underside of leaves may appear dusty from the empty egg casings and molted skins.