Sunday, November 29, 2009

Ephemeroptera

For now, this page shall be only order, until I am able to fully key this mayfly - I fear that it had a final molt to go, since it only had one pair of wings visible and does not seem to fit into the families with absent hind wings so as a result, may be difficult to key. It also had fine hairs on the wing margins, indicative of subimagos. At any rate, here is some information about the order Ephemeroptera - Mayflies - and a few lovely pictures.





Mayflies are small-medium, elongate, soft-bodied insects with two or three thread-like tails. They are common near ponds and streams. They have membranous wings with dense venation and the front pair of wings is usually large and triangular while the hind wings are small or absent. They live most of their life as an aquatic nymph, with leaflike or plumose gills along the side of the abdomen. Most feed on algae and detritus, contrasted with the highly carnivorous dragonfly nymphs. They rise to the surface of the water, molt into a subimago, land in a safe location and wait for their final molt to the adult form. The subimagos have a pair of wings, but the margin has hairs, as do the caudal filaments (see below). The nymphs may take a year or two to develop, but the adults live only a couple days at most.

Saturday, November 7, 2009

Rhaphidophoridae

After investigating the families of camel crickets a little further after that survey, I decided it was not so difficult to identify that it was worthy of an entry. Insects of the family Raphidophoridae are in the order Orthoptera (Crickets, Grasshoppers, Katydids), and are commonly called camel or cave crickets. They differ from other families of Orthoptera in that do not usually have wings, are hump-backed in appearance, and often live in caves, hollow trees, or other dark moist places. They have very long antennae, and most species belong to the genus Ceuthophilus.





Orthoptera; Ensifera; Rhaphidophoridae, Pristoceuthophilus sp.
Common Name: Camel Cricket

Information about this genus is rather sparse, with data from Washington, Oregon, and California. Other species include names such as P. arizonae, P. pacificus, and P. californiana, so they are somewhat widespread on the western coast of the US. This genus is relatively easy to distinguish from others, as the males have an obvious "crook" in their hind tibiae and a pronounced hind femoral tooth, both visible in one of the pictures above. The top image contains a female, and the bottom two images are of the same male. Also note the large spike coming from the apex of the female's abdomen - that is the ovipositor, with which she deposits her fertilized eggs.

Sunday, November 1, 2009

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.