Written by  David Williams, Agriculture Victoria, Tatura

Mite management in orchards (part 2)

European red mite (ERM) is a dark red mite about the same size as TSM.

ERM (Continued from last issue)
ERM is a dark red mite about the same size as TSM.
It has white tubercles, with strong hairs (setae) protruding from the tubercles, on its back. ERM overwinters as dark red, onion-shaped eggs that have a spine arising from the central top. These eggs are laid around the bud scales on twigs and shoots.
The white tubercles on the backs of the adult mites, and the spines on the eggs, are easily seen with the aid of a hand lens.
The overwintering eggs hatch around the green-tip stage of tree development in spring and the nymphs move to the developing leaves.
This pattern of egg laying means that ERM infestations are more widespread throughout the tree than are TSM infestations.
Where ERM and TSM appear on the same leaves ERM will usually inhabit the upper surface of the leaf and TSM the lower surface.
ERM does not produce much webbing. ERM appeared in orchards on the Mornington Peninsula in the 1980s and spread to Gippsland, Yarra Valley, Bacchus Marsh, North-East, and Harcourt. It has been found in small pockets in the Goulburn Valley since about 2000.
Biological control
Predatory mites were introduced to Victoria to control ERM in the 1980s and the comments regarding biological control of TSM hold equally for ERM.
Bryobia mites (cont next issue)

See this article in Tree Fruit Feb 2019