Tetranychus spp., Paratetranychusspp. and Olygonychusspp.

Nature of damage

• Mites can damage maize from the seedling stage to maturity.
• Spider mite injury is inflicted through piercing and sucking on the foliar tissue.
• As the colonies of mites increase in size, they cause the lower leaves of the maize plant to become dry; the mites then migrate to the upper leaves.

Signs

• The presence of small, faint, yellow blotches on the lower leaves.
• On the underside of damaged leaves, one can observe tiny green to reddish brown mites protected by a delicate web secreted by the adults (Paratetranychus spp.) whose eggs have a pearl-like appearance.

Factors favoring development

• Mites (which are more closely related to spiders than insects) go through a larval and two nymphal instars and multiply very quickly in hot, dry weather.

Geographic distribution

• Worldwide distribution.