Like the psyllids, the eriophyid mite complex associated with M. alternifolia is unknown and no species are described. However, eriophyids occur all year but the damage is more apparent in the winter and spring.
The eriophyids distort new foliage and cause the leaf margins on the ventral surface to bend; cells on the leaf surface within the distorted area bubble and become hairy. The mites live within the distorted areas. Eriophyids prefer new growth but also occur on basal growth near the ground. Removal of foliage from the residual stems after harvesting, for example with a flame weeder, may delay the colonisation of new growth with mites. The value of flame weeders in this role needs confirming. Growers can check for the presence of mites by gently heating the distorted foliage and examining it with a hand lens. Heat causes the mites to become active and move about within the distorted foliage.
Work by the authors indicates varietal differences in susceptibility of monoclonal plants to the eriophyids. Current work by D.Knihinicki (NSW Agriculture, Orange) should resolve the taxonomy and ecology of mites associated with M. alternifolia.
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