Stenopelmatidae Part 2

After my disappointment that I couldn't find a live specimen for my first Stenopelmatidae post, I found one in my pool, extremely distended but perfectly preserved, and thought it a good opportunity to show off some insect anatomy. Below, I have an unlabeled photo and a labeled photo of the "face" of one of the Stenopelmatus species.

Stenopelmatus sp.

In case any of the labels are too hard to read, here they are listed, generally from top to bottom: Frons, Pedicel, Scape, Anterior Tentorial Pit, Frontoclypeal Suture, Clypeus, Abductor Tendon, Mandible, Labrum, Stripes, Postmentum, Prementum, Lacinia, Paraglossa, Hypopharynx, Galea, Maxillary Palp, Labial Palp. Now for a few other lovely pictures - In the ventral view, you can see the soft, unsclerotized endoskeleton that connects the sclerotized shield-like segments. This is necessary for insects, because if their whole exoskeleton were fused and sclerotized they would be unable to move.

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.

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.

Stenopelmatidae

Apologies for the hiatus - I have been trapped by medical school obligations and it's hard to find a spare thought for other concerns. I will upload a picture as soon as the specimen is done drying (probably a week from now), but since it was an easy identification, I thought I would make a preview post. A common, large insect in California is the Jerusalem Cricket, family Stenopelmatidae. There are only two genera within the family: Ammopelmatus, which is critically endangered and only found in California in the Kelso Dunes of the Mojave Desert and coastal Point Conception, and Stenopelmatus, which is widespread. The insects are approximately 1.5-2 inches in length, with an awkward gait. They are wingless, have long antennae on a large head, and a black-banded abdomen.

Orthoptera; Ensifera; Stenopelmatidae; Stenopelmatus
Common Name: Jerusalem Cricket, Potato Bug

This family is unique in Orthoptera, for lacking wings, overdeveloped hind femurs, and auditory organs. They communicate with one another by producing vibrations on the ground with their abdomen, in place of rubbing their wings together as do most true crickets. Jerusalem crickets feed on decaying plant matter and some small insects, and are capable of burrowing into soft ground. They also emit a pungent smell, particularly upon death. The scent is similar to that produced by mantises and other insects. They are mostly nocturnal, so they are often encountered when gardening, lifting up logs and rocks, or when cleaning out pool filters.

Acrididae

A recent grasshopper I have pinned is in the genus Schistocera, or bird grasshoppers. They are called bird grasshoppers because they are very large - this specimen is approximately three inches long, with a five inch wingspan. This species is common in Southern California, and were caught in Los Angeles County.

Orthoptera; Acrididae; Cyrtacanthacridinae; Schistocera nitens
Common Name: Gray Bird Grasshopper

The subfamily Cyrtacanthacridinae contains 12 species, and Schistocera is the only genus within the subfamiliy. Most of them are large and strong fliers. The name Schistocera comes from the Greek skhistos (σχιστος)- "split or divided" + kerkos (κερκος)- "tail". This genus includes the locust famous for swarming in Egypt, Schistocera gregaria. There was once a swarming locust of similar agricultural significance in North America, the Rocky Mountain Locust (Melanoplus spretus), but it was wiped out - possibly by farmers destroying its larval/egg/pupa stage by plowing the land. It is thought to have swarmed in the largest numbers known among animals: one swarm containing an estimated 12.5 trillion insects. In 1874, entomologists sighted a swarm that covered 198,000 square miles - greater than the area of California. At any rate, they are extinct since ~1905 and specimens can be found in glaciers, for the time being. However, that species was a member of the subfamily Melanoplinae, spur-throated grasshoppers, while the bird grasshoppers are in the subfamily Cyrtacanthacridinae, miagratory bird locusts.

Acrididae

Here are a couple grasshoppers common in California. An unfortunate side effect of preserving grasshoppers is that they tend to discolor and become more orange than they were when first caught. For newly collected insects, I will try to photograph them while they are still alive, to preserve their color. The same goes for Katydids, who become a duller green after they are collected.

Orthoptera; Caelifera; Acrididae; Oedipodinae; Trimerotropis pallidipennis
Common Name: Pallid-Winged Grasshopper

These grasshoppers are of the family Acrididae, or Short-Horned Grasshoppers, which includes the swarming locust variety. They are a distinct family for having relatively short antennae and tympana (or sound organ) on the side of the first abdominal segment. They are extremely common in California, and tend to have a mottled, variable color - some are extremely dark, others extremely light. These two specimens are approximately 1.5 to 2 inches long, found in San Diego. The subfamily, Oedipodinae, refers to "band-winged grasshoppers," based on the color bands on the wings. The distinguishing characteristic for the genus, Trimerotropis, is that the front wings have dark markings, and the ridge on the posterior half of the thorax is faint or absent.

Tettigoniidae

The following are two species of Katydid - the medium-sized one I thought was an instar of the larger one, but apparently they are different species. Each is about 3 inches long, wingspan about 4 or 5 inches. The largest and smallest specimens were caught in the San Diego area, and the medium specimen was caught in La Verne.

Orthoptera; Tettigoniidae; Phaneropterinae; Microcentrum rhombifolium
Common Name: Greater Angle-Wing Katydid



Orthoptera; Tettigoniidae; Phaneropterinae; Scudderia mexicana
Common Name: Mexican Bush Katydid



Orthoptera; Tettigoniidae; Phaneropterinae;
Unknown nymph - possibly Scudderia mexicana, Microcentrum retinerve (Lesser Angle-Wing Katydid), or Microcentrum rhombifolium.

Katydids communicate through song, and the subfamily Phaneropterinae is commonly called "False Katydids." They can vary in color from brown, to pink, to green, and often mimic leaves. The Greater Angle-Wing Katydid is differentiated from the Lesser Angle-Wing Katydid by a small tooth on the dorsal, frontal edge of the thorax - that part of the Lesser Angle-Wing Katydid is smooth. The Greater Angle-Wing Katydid is common in Southern California. They eat plant material and develop through several molts called instars, the final instar being winged. As a mating ritual, the male brings the female a nuptial meal, a spermatophylax, which is a gelatinous blob of carbohydrates, protein, and water. The male mates with the female while she is consuming the spermatophylax. As a result, the larger the meal, the longer it takes the female to consume it, and the longer time the male has to inseminate her, thereby producing more offspring.

As for the Mexican Bush Katydid, it is a member of the Scudderia genus, or Bush Katydids. Bush Katydids do not fly often, but glide from bush to bush and their forewing is noticeably shorter than the hind wing, with an elongate, narrow appearance relative to other genera. The species are mostly differentiated through male genitalia, and I did not key this specimen to species - I merely suspect it is Scudderia mexicana. The nymph may be a member of Scudderia because its femur is smooth, compared to Microcentrum which has spines on the femur.