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written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA

‘Midnight marauders’ were the topic of one of my columns a while back. Before I launched an updated version this week, I checked to see when I wrote the previous one. It was in May of 1989. It’s definitely time to bring you up to date on the creatures that plunder our gardens under the cloak of darkness.

If no culprits can be found feeding on damaged plants during the day, the best way to determine what miscreants are at fault is to venture out after dark with a flashlight and catch them in the act. Here are the culprits you’re most likely to find.

SLUGS: Many gardeners new to the area don’t think we have slugs here, but area gardens do host these slimy mollusks that munch on plants at night. Sometimes in early morning you can see a glistening trail of slime that they’ve left behind on plants. Slugs will feed on both the tender leaves of young plants, as well as the tougher leaves of older plants. On older plants their damage is characterized as ragged chewing. On younger plants they devour large parts or entire young seedlings. According to WSU Hortsense, additional evidence of their presence includes ‘pretzel‑shaped’ fecal droppings.

EARWIGS: Most area residents are familiar with earwigs, those reddish brown fast-moving insects about three-quarter inch in length with a set of pincers at the end of their abdomen. During the day they like to hide in dark, moist tight spaces. I suspect they’ll be numerous in area gardens this year because they prosper when spring and early summer weather is wet.

These omnivores are considered beneficial because they feed on insect pests like aphids and mites, but they also feed on tender plant tissues, such as young seedlings and delicate flower petals. They can decimate seedlings, but on older leaves their feeding is characterized by small to large irregular holes and damage along leaf edges. On the surface of ripe soft fruit, including peaches and strawberries, they’ll leave shallow holes. Earwigs also feed on corn silks interfering with kernel formation.

CUTWORMS: Cutworms are the larvae or caterpillars of night flying moths and get their name because some cutworms eat around the base of young plant stems which results in ‘cutting’them off. Cutworms are not remarkable in appearance. They have hairless tan, gray or greenish bodies with various indistinct markings. Ranging from one quarter to one inch in length, they curl up when disturbed. They hide under plant litter, soil, and mulch during the day. Their main source of food is weeds, but they also feed on garden plants.

ROOT WEEVILS: Root weevils are another pesky nighttime insect. The adult weevils are black to brown snout-nosed beetles about one quarter to one half inch in length. Their damage is characterized by notching of leave edges, making them look like someone has cut along the leaf edge with pinking sheers. Root weevils attack over 100 plant species but seem particularly fond of lilac, euonymus, strawberries, peony, rose, rhododendron, and azalea. During the day they hide under plants in loose soil or plant debris.

If you go to bed as soon as the sun sets or you

re nervous about looking for nocturnal pests in your garden after dark, you can try trapping the offenders by placing damp, tightly rolled up newspapers near the plants under attack. Check the traps in the morning for slugs, earwigs or root weevils. Next week we’ll talk about what control approaches work best for these midnight marauders.

Published: 6/15/2012 2:54 PM



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