A Pocket Guide Common Natural Enemies
of Crop and Garden Pests in the Pacific Northwest
EC 1613-E December 2007
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Using this Guide
The cards in this guide are designed to help you quickly learn the main groups of natural enemies of crop and garden pests, their predacious activity, and tips for observing them. Photographs are of the most common species in the Pacific Northwest.
Use this guide as a field supplement to other publications that provide more detail on how to scout for and manage specific pests and natural enemies.
Print each sheet on regular paper or cardstock. Then fold on the central horizontal line and cut on the dotted orange lines to create three 2-sided cards. (Laminate if needed.)
Most of the photographs in this pocket guide are from the Ken Gray collection.
All other photographs are from the author.
Determine the relative populations of pests and natural enemies with preliminary monitoring. Then use the following tactics to enhance biological control as part of an IPM program.
Protect natural enemies from disturbances such as pesticides, other management practices, their own natural enemies
g., ants), or adverse environmental conditions.
Provide supplementary nectar or pollen sources, alternate hosts, or shelter.
Manipulate the behaviors of natural enemies with attractants or with plant structure and arrangement.
Augment natural enemy populations with mass releases of lab-reared individuals.
Introduce natural enemies that are
absent from the area.
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General Observation Tips
When doing visual counts, also inspect the undersides of leaves.
Approach fast-moving insects slowly, or use nets, beating trays, and traps to get a closer look.
Distinguishing Natural Enemies from Plant Pests in General
Observe the specimen to see whether it feeds on animals or plants.
To see whether a particular natural enemy attacks a target pest species, place individuals of both species together in an enclosed environment that allows them room to move.
(Coleoptera: Coccinellidae) Identification
Adults orange to red with black spots, or mostly black; larvae longer; eggs in clusters.
1 ⁄ 8 – Adalia bipunctata 1 ⁄ 3 "
Observation tips All stages found on plants.
Adults and larvae prey on aphids, scale insects, mites, and other small insects.
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Green and Brown Lacewings
(Neuroptera: Chrysopidae and Hemerobiidae)
Light green or brown, large wings, long antennae; larvae flat with long mouthparts; eggs on stalks.
Green lacewings, e.g., Chrysopa californica
Adults often seen flying or on plants; eggs and larvae on plants. Brown lacewings, e.g., Hemerobius spp. Predacious activity
Larvae and adults mostly prey on aphids, mealybugs, and other small insects.
1 ⁄ 2 – 3 ⁄ 4 "