THE BUG MAN: Earwigs

By James A. Bethke, for Let’s Talk Plants! July 2022.

James Bethke

Figure 1. The European earwig, Forficula auricularia L. Photo from Pixabay.com.


Earwigs


A television show that I will never forget was called “The Caterpillar”, an episode of The Night Gallery by Rod Sterling (https://thewordwebzine.weebly.com/tv/night-gallery-earwig-episode-might-be-greatest-horror-tv-episode-ever). The actor was supposed to put an earwig in a rival’s ear, and it was supposed to produce such great pain and agony as it fed that it caused the person to want to die. Unfortunately, the earwig ends up in his own ear instead. He survives the agony only to find out that the earwig had eaten through his brain and laid eggs on the way out the other ear. Cool!


While this was an entertaining story as a child, earwigs don’t, in fact, attack people. However, they can be a pest for gardeners. Earwigs are in the insect Order Dermaptera, an Order all to themselves. Earwigs are mostly scavengers or omnivorous, but they can be predatory on other insects. Most likely, they are opportunistic. If there is a good food source, they will exploit it. They are nocturnal and hide during the day in a cool, moist environment. There are plenty of misconceptions about earwigs. They use their pincers to protect themselves, but they are not poisonous, nor do they carry diseases.


Oddly enough, in our area the most common earwig found is an invasive earwig called the European earwig, Forficula auricularia L. (Fig. 1) The most common native species in our area is the ring-legged earwig Euborellia annulipes (Gené) (Fig. 2). The two species are easily separated. The European earwig has two brown wing pads that contain long leathery wings, and yes, they fly. The ring-legged earwig is wingless, much darker in color, and they have shorter pincers than the European earwig. Both species exhibit a form of parenting by guarding their eggs and newly hatched young. You may see this if you turn over stones or boards in your yard in the spring.

James Bethke.

Figure 2. The ring-legged earwig, Euborellia annulipes (Gené). Photo by James A. Bethke.


Earwigs, however, can be a real hassle in the home garden and landscape because they eat the leaves and petals of a wide variety of foliage plants. Years ago, I grew a great number of artichokes in my garden. My first harvest was awesome, and I put them in our sink and covered them in water to wash them before cooking. When I returned to finish cleaning the artichokes, I found about a hundred earwigs in the sink. Apparently, an artichoke flower bud is an excellent place to hide and feed. In a good search of my garden, I found tremendous numbers of earwigs under pieces of plywood I used as steppingstones.

Earwigs are also known as a pest of young citrus trees. They will hide at the soil level during the day and move up the plant at night to feed on the new flush growth. Some citrus growers use plastic sleeves to protect the trunk of young trees. The earwigs hide in these sleeves in great numbers then move up the young plant at night.


I don’t use pesticides in my garden, so I used a couple of other tricks that I am aware of to get rid of earwigs. I tried pitfall traps, but I caught all manner of things, some of which I wanted to keep in the garden like small lizards and centipedes. I resorted to the hand vacuum. Yup! I would suck them up from under the boards in the hundreds every so often. Unfortunately, earwigs have a scent gland that emits a very strong smell, and the hand vac became an outdoor device soon afterward.


Another trick that worked very well was the use of empty paper towel rolls. I pinched one end shut, got the roll wet and placed it in a well shaded area of the garden. The next day, I would pinch the other end, place it in a plastic bag and trash it. There are lots of ideas like that that can be used as pest control methods in the garden in lieu of pesticides. Pesticides are likely a poor control alternative for earwigs.

 

James A. Bethke is the Floriculture and Nursery Farm Advisor Emeritus for San Diego and Riverside Counties.


The Floriculture and Nursery Farm Advisor Emeritus conducts applied research, education and outreach programs to improve production and viability of the floriculture and nursery industries in San Diego and Riverside Counties.


Jim's program emphasizes the integrated pest management of major pests of floriculture and nursery production. He collaborates with regulators, growers, and other scientists on advisory committees that set policy based on science.