Forficulidae

I think I'm starting to get lazy - when I realize I happen to have a picture of an insect which I have already identified and haven't yet done an entry about, I just pick that one to write about instead of getting out the scope and keying one of the ones I have on my pinning board. For this entry, I have chosen Forficula auricularia, or the European Earwig. Earwigs are very interesting insects, which most everyone has come across at one time or another, and in the US that type is almost always the European Earwig. Earwigs make up the order Dermaptera, and consist of slender, elongate, somwhat flattened insects that have forceps-like cerci (apical extensions from the abdomen). Adults may be winged or wingless, most have short, leathery, veinless wings that do not reach very far down the abdomen. They are hemimetabolous, meaning the immature earwigs look like miniature adults, though they have fewer antennal segments. They also have male abdomen characteristics (10 segments) and female cerci characteristics (straight forceps, not curved). The forceps are the easiest way to determine gender in mature earwigs.

Dermaptera; Forficulidae; Forficula auricularia
Common Name: European Earwig

Earwigs are generaly nocturnal and hide during the day in cracks, crevices, under bark, in flowers, in debris, etc. They mostly feed on dead and decaying vegetable matter, but some feed on living plants and a few are predaceous - both of the earwigs pictured above are male, based on the forceps, and the lower male is feasting on a small insect. Earwigs, like the Orthopterans and Mantids, are capable of emitting a foul-smelling fluid, which some are able to squirt for a distance of 1 cm. Earwigs do not bite, but are capable of pinching with their forceps when handled; it does not often break the skin. Unlike their name, they do not enter people's ears. Earwigs overwinter as adults, and the females exhibit maternal behavior - they guard their eggs until they hatch, and even then they look after the nymphs until they are ready to take care of themselves.

The family Forficulidae includes European and Spine-tailed Earwigs. The European earwig is the most common - it is a brownish-black insect 15-20 mm long and is distributed across North America. It can cause significant damage to crops and ornamental plants.

Random Night Survey

I came across a sleeping Jerusalem Cricket earlier and somehow it didn't occur to me to take a picture, since I have that one posed and drying on the pinning board. Since they're nocturnal I thought I might look around outside and see if I came across any - as there are three at the bottom of our pool right now. I ended up running into different insects plus arthropods, gastropods, and salamanders. Below are the pictures - with quick general identifications.

Formicidae (Ants), Xystodesmidae (Millipede Family), Coleoptera (I have three specimens, will devote a later entry to more specific identification), Machilidae (Bristletails)




Machilidae, Xystodesmidae



Raphidophoridae (Camel Crickets), Pulmonata (Slugs, Snails)



Coleoptera, Forficula auricularia (European Earwig)



Carabidae?(Ground Beetle), Pulmonata, Anisolabididae (Ring-Legged Earwigs, male based on asymmetric pincers)



Pulmonata, Diplopoda (Millipedes, Class)



Forficula auricularia, Ensatina eschscholtzii (Monterey Ensatina)



Batrachoseps attenuatus (California Slender Salamander)



Pulmonata eggs, Araneae (Spider) eggs, Pulmonata



Agelenidae (Funnel-Web Spiders), Lumbricina (Earthworm)

Eventually I'll get around to keying the three Coleopterans, but at this point I still am rather busy with medical school. I should make it a habit to do night surveys - they're a lot of fun. Thanks to Phil for the salamander IDs - it pays to have a friend who knows herps and amphibians.

Chelisochidae

While in Hawaii, I took pictures of whatever insects I happened across. As it turns out, I came across a black earwig, family Chelisochidae, of which there is only one species. It is most common on islands in the Pacific. The passage from Borror and DeLong indicates that they may be found in California. Earwigs are members of the order Dermaptera, and are found all over the world. They can pinch with their rear pincers if disturbed, and feed on small insects such as caterpillars. I would have collected this as a specimen, as it is one of the families we need, but I did not know at the time whether it was a native species to Hawaii. Unfortunately, many native insects in Hawaii are threatened by invasive species. Regardless, I will be keeping my eye out for any in California - down in San Diego is probably one of the more likely places they will be as it is closest to tropical, and this species prefers moist climates.

Dermaptera; Chelisochidae; Chelisoches morio
Common Name: Black Earwig

The word Dermaptera comes from the short leathery wings, "derma" referring to skin and "ptera" to wings. There are approximately five families of Dermaptera, depending on which taxonomic guide one uses. The most common one seen in California is the European Earwig, family Forficulidae. Earwig females lay a dozen or so eggs, and some remain by the eggs until they hatch.