With a hand lens and photo-illustrated guide by Oregon State University Extension and Oregon Tilth, you can teach yourself to identify beneficial insects that prey on your crop pests.
The just-released guidebook, "A Pocket Guide: Common Natural Enemies of Crop and Garden Pests in the Pacific Northwest" – publication EC 1613-E – offers macroscopic photos of many natural predators and parasitoids in their life stages, along with identification and observation tips.
It is available on line for no charge at http://ipmnet.org/Pocket_Guide_of_Natural_Enemies.pdf.
The Farmscaping for Beneficials program at OSU's Integrated Plant Protection Center works with PNW growers to help foster beneficial invertebrate predators and parasitoids and native pollinators on their farms. These tiny creatures can help control crop pests such as aphids, cutworms, earworms, slugs, leaf miners, spider mites and earwigs.
"Predators and parasitoids that can manage farm and garden pests include lady beetles, predator mites, hoverflies, the green lacewing, damsel bugs, stinkbugs, parasitic wasps and predacious ground beetles," explains Gwendolyn Ellen, coordinators of Farmscaping.
"The trick is to learn to tell the good bugs from the bad."
That's where the guide will help, as well as additional photos of beneficials that can be viewed at http://mint.ippc.orst.edu/beneficalinsects.htm.
The new release prints out in four pages of colorful illustrations of various stages of each of 19 beneficials, providing pictures of various life stages of each.
The printout is designed to be best reproduced on cardstock, which can be cut into reference cards and laminated, if desired, for regular use in checking your plantings.
Protection of biocontrol beneficials is important, the guide reminds, and provides these tips to make sure you encourage good bug populations:
n Be careful using pesticides which can destroy beneficial populations
n Provide nectar or pollen sources to encourage beneficial populations
n Manipulate beneficial behavior using attractants or plant structures.
n Augment natural enemy populations with mass-releases of lab-reared individuals.
n Introduce natural enemies that are absent from some areas.