Earwigs
Forficula auricularia



As we have all noticed, the earwigs are out of control this year! I have done some research, and will try to give you a helpful summary.

Earwigs lay their eggs in the fall. The mothers guard the eggs all winter, until spring warmth comes and the eggs hatch. At this point, the earwigs all emerge--man, woman, and child-- to FEED! The earwigs are ominvores, eating aphids and slugs (YES!) as well as marigolds, corn silks, and many other of our favorite vegetable leaves (NO!)! They are most active in our valley during May, June, and July. Many people have said that this is the worst year for earwigs in Davis in a very long time.

An adult earwig looks like this:

Image of a earwig. Gross.

Damage looks like this (it may look differently, too... if there is severe damage in your garden right now, it is most likely earwigs. If you're not sure, visit your garden at night with a flashlight. You'll see them. 

Basically, trapping is the most effective method of controlling earwigs. Earwigs are active at night, retreating to a dark, moist place in the mornings. Set a trap in the afternoon or evening; the following morning you will be able to shake dozens of earwigs out of your trap to their deaths in soapy water. Or you can relocate them, but please take them FAR! Rolled up newspaper makes a great trap. You can also pack straw into a flowerpot and leave it upside-down.

Another option is an oil trap. Use a fishy-smelling, unwashed, short tin can (tuna cans and catfood cans are ideal). Pour several centimeters of vegetable oil into the bottom. The earwigs will be attracted to the fishy smell, crawl in, and drown in the oil. Be sure to change the oil regularly.

The earwig's only insect predator in North America is the tachinid fly. It is attracted to alyssum, calendula, dill, and fennel. It looks like this: 

Diatomaceous earth, a powder made of ground diatom skeletons (diatoms are ancient tiny organisms dug from the earth... no cruelty involved!), may also be used, but it has to be re-applied fairly frequently. The microscopically sharp edges of the particles pierce the bodies of crawly pests, killing them. Diatomaceous earth does not harm earthworms! It is available at Redwood Barn and Ace.

Here are some good websites for more information:
  http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74102.html
  http://cecommerce.uwex.edu/pdfs/A3640.PDF
 

Please consider trying some sort of earwig control in your plot... your plants and your neighbors will appreciate it!