European Red Mite, Panonychus ulmi (Koch)

Description and Life Cycle

The European red mite causes considerable damage to apples in some orchards, it also becomes a problem in vineyards from time to time. 

The adult female of the European red mite is dark red to reddish-brown, has eight legs and is about 1/50 inch long.  Adult male mites are smaller than females and have a pointed abdomen; they are usually dull green to brown.  Eggs, which are globe-shaped and red, are laid on the undersides of leaves in the summer.  The eggs are tiny and require a magnifying glass to be seen.  During late summer and early fall, eggs are laid around cane nodes, where they overwinter, several generations occur each season.

Damage Symptoms

The adults and nymphs of this species feed on the undersurfaces of leaves, and in heavy infestations, the leaves turn a bronze color.  If bronzing occurs early enough in the season, a negative effect on fruit ripening may occur as feeding may interfere with the normal photosynthetic process of the leaves.

 

Management

Growers should apply miticide sprays before bronzing occurs.  In some vineyards, this pest is kept at low levels by naturally occurring predatory mites and predaceous insects.

Monitoring

Monitoring for European red mite can be accomplished by looking at the underside of the leaves for their presence at the same time you are scouting your vineyard for leafhoppers and grape berry moth.  You may also keep a close eye out for bronzing while traveling through the vineyard on your tractor.  This can be done at the same time your applying fungicide sprays to your vineyard.