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How to Manage PestsUC Pest Management Guidelines
DESCRIPTION OF THE PESTSOmnivorous leafroller is the most common and damaging of the leafrolling caterpillars. Omnivorous leafroller caterpillars may differ in body color from cream to brown with light brown to black head capsules and resemble other tortricid species, except that they have white, slightly convex and oval tubercles at the base of each bristle on the upper side of the abdomen. Orchards may be infested with omnivorous leafroller moths that develop on host plants outside the orchards. Omnivorous leafroller has four to six generations per year depending on climatic conditions. Fruittree leafroller, obliquebanded leafroller, and orange tortrix may also attack kiwifruit. Fruittree leafroller is a minor pest of kiwifruit that only has one generation per year. Overwintering eggs hatch in spring, and larvae can be found feeding on leaves until about June. The larvae are dark green caterpillars with black heads. Adult moths appear in June or July and lay the overwintering eggs. Obliquebanded leafroller may be the most common leafroller found in the Sacramento Valley. It has two generations per year in the Sacramento Valley. Larvae are green to tan-colored caterpillars. Orange tortrix is mostly found in the cool, coastal regions where it has two to four generations per year. The larvae vary in color but are generally yellowish tan to light brown. DAMAGEOmnivorous leafroller and the other leafrolling caterpillars directly damage fruit by scarring the surface when they feed. MANAGEMENTClosely examine blossoms and vegetative shoots in the orchard during prebloom and bloom for the presence of caterpillars, webbed leaves, or feeding damage. If present, or if leafroller damage was evident in previous harvest, a postbloom treatment is justified. This postbloom treatment is often sufficient to keep leafrollers under control for the remainder of the season. Decisions to treat summer generations of the omnivorous leafroller should be based on the presence of caterpillars observed from periodic visual inspection of the vines, not from moths caught in traps. No correlation exists between pheromone trap catches of adult moths and damage.
Biological Control
Organically Acceptable Methods
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UC IPM Pest Management Guidelines: Kiwifruit |
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