Southern Red Mites exploding

The long cool spring seems to have been great for cool season mites. In North Carolina,

Adult southern red mite. Photo: SD Frank

Adult southern red mite. Photo: SD Frank

the most important cool season mites are the spruce spider mite (Oligonychus ununguis) and southern red mite (Oligonychus ilicis).   These are among the earliest and most damaging pests in nurseries and landscapes. As their name implies, cool season mites are active in spring and fall when they suck fluid from cells on plant leaves and needles. In hot summer months these mites are dormant. However, it is summer when their damage becomes apparent as chlorophyll bearing cells die. Thus, by the time plants exhibit aesthetic damage the mites are gone and treatment is wasted.

Today I found all stages of Southern red mite on cherry laurel but is feeds on many broadleaf evergreens such as azalea, camellia, holly, and rhododendron. With eggs juveniles and adults all present these mite populations are well underway and deserve attention from nursery and landscape personnel.

Multiple southern red mite life stages on cherry laurel. Photo: SD Frank

Multiple southern red mite life stages on cherry laurel. Photo: SD Frank

Scout plants that had mites or mite damage the previous year as they are likely to have them again because the mites have overwintered as eggs. You can identify plants that had mite last year by looking for fine stippling damage on the old leaves. Turn them over and look with a hand lens for silk webbing, shed skins, and mites. On broadleaf evergreens, look on the underside of leaves for the southern red mite. The most efficient method of scouting for cool season mites (and other mites) is to hold a piece of white paper or a paper plate below a branch and strike it with a pencil or stick to dislodge arthropods. Spider mites will appear as tiny moving specks about the size of the period at the end of this sentence.

Southern red mite damage on cherry laurel. Photo: SD Frank

Southern red mite damage on cherry laurel. Photo: SD Frank

For more information and control options consult the NCSU insect note at http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/ort077e/ort077e.htm

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s