Tuesday, May 26, 2009

Blattidae

The family Blattidae contains cockroaches with spines on the posterior ventral side of their middle and hind femurs and reach lengths over 18 mm. Also, the females have a longitudinally divided genital plate, and the males have slender, symmetrical styli. Within this family, there is one species called the Oriental Cockroach, which is the only one in the family where the adult has wings which do not completely cover the abdomen. It is a common pest in the United States, and this specimen was found by the beach.



Blattodea; Blattidae; Blatta orientalis
Common Name: Oriental Cockroach

They reach lengths of approximately 25 mm and the females are nearly wingless. They are also known as waterbugs, since they prefer dark moist places. They also prefer humid places, so San Diego is perfect for them. They are easily differentiated from German and American cockroaches by their shorter wings. They are larger than German cockroaches, and slightly smaller than American cockroaches. American cockroaches also have the ability to fly.

Hornworms

The cocoon below contains the larvae of a hornworm, most likely the Five Spotted Hawkmoth, and is a major pest of Tomato crops particularly. No way to know what it is exactly until it hatches. The larvae can be about two inches long, and almost a centimeter wide. Usually it is green with small white or yellow stripes along the side, but there are varying colors. For some pictures of the larvae, check here. Once the larvae have had their fill of the plant, they burrow into the ground and form a cocoon. Recently, my dad found one buried in the loose dirt near his tomato plants.



Lepidoptera; Bombycoidea; Sphingidae; Sphinginae; Sphingini; Manduca
Common Name: Tomato Hornworm/Five-Spotted Sphinx Moth (?)

I will update once it hatches - until then, it shall remain mostly a mystery. I can be certain it is of the genus Manduca at least, considering the cocoon type and its location. The cocoon is about two inches long, and the loop on one end contains the developing proboscis of the moth. When disturbed, it wriggles its pointed end.

Monday, May 25, 2009

Myrmeleontidae

The order Neuroptera is less well-known than the beetles, butterflies and moths, plant bugs, and flies. It contains soft-bodied insects with four membranous wings that have many crossveins and extra branches of the longitudinal veins. The name comes from the Greek word "neuron," meaning sinew, and "ptera" meaning wings. Hence, they are also known as the nerve-wing or net-wing order. The most common Neuropteran is the lacewing (suborder Planipennia, family Chrysopidae), which eats aphids and is usually a pretty green with delicate translucent wings. A previous entry described snakeflies (order Neuroptera, suborder Raphidioptera). I now bring you the antlion.





Neuroptera; Planipennia; Myrmeleontoidea; Myrmeleontidae; Dendroleon obsoletus
Common Name: Spotted Winged Antlion

The antlion begins its life as a rather scary looking larvae that digs a cone-like pit in the ground and waits for ants to fall into its waiting jaws. The larvae are also called "Doodlebugs" and have sicklelike jaws. Eventually, it pupates into a four-winged adult. The above-pictured antlion was found in Virginia, and is most common on the east coast of the United States. Antlions are the largest family of the order Neuroptera, and other species are common throughout the country. They differ from damselflies in that they are softer-bodied, have relatively long, clubbed antennae (which fell off on the above-pictured specimen), and very different wing venation. They are rather feeble fliers, and are attracted to lights. There are 13 genera containing 92 species.

Thursday, May 21, 2009

Theridiidae

I went out for a random night foray and saw a lovely black widow sitting in a corner. I tried to find food for her, but unfortunately beetles tend to fall through their very haphazard webs. The males are smaller and do not have the red hourglass shape on the abdomen. They court the female by bringing a dead insect as a nuptial gift, but of course run the risk of being eaten themselves. I have always liked black widows, since they are beautiful spiders, somewhat dangerous, and very cool hunters. I had the pleasure of capturing one and I threw a crane fly (tipulidae) into the jar with it. The crane fly was flying very fast and erratically, and the black widow was sitting at the bottom, a sticky thread between her front pair of legs, and in a split-second she lunged at the crane fly and caught it with the string. It was really remarkable - they have such amazing reflexes. Here are the lovely pictures.




Arachnida; Araneae; Araneomorphae; Entelegynes; Theridiidae; Latrodectus hesperus
Common Name: Western Black Widow

The family Theridiidae contains cobweb spiders, which spin webs that are three-dimensional or mesh sheets, instead of a traditional orb web. Usually these spiders have eight eyes, rarely six. The genus Latrodectus, which contains black widows, is widespread in the US. The venom is a neurotoxin, and symptoms of envenomation include swelling of the lymph nodes, profuse sweating, rigidity of the abdominal muscles, facial contortions, and hypertension. Antivenin is readily available, and no deaths have been linked to black widows since the 1940s. For more information on the biology of black widow venom, see my medical blog.

Cerambycidae

These shots are of a beetle, family Cerambycidae, and most likely tribe Lepturini - without a key it is difficult to pinpoint the genus-species, since within the groups there is variable coloring. At any rate, it enjoys hanging out in flowers. The elytra are broadest at the base and narrowed near the apex. The larvae bore into the pith of flowers. The adults are often colored with yellow and black bands or stripes, but also orange, blue, green, red, and other bright colors. They are excellent fliers, and sometimes the last segment of the abdomen is exposed. Despite their larvae consuming flowers, the adults are probably important pollinators.





Coleoptera; Polyphaga; Chrysomeloidea; Cerambycidae; Lepturinae; Lepturini
Common Name: Flower Longhorn Beetle

Tuesday, May 19, 2009

Updated Insect Collection

I recently labeled and placed in the appropriate boxes approximately 40 insects, so my collection is looking a lot more respectable now. Here are the big four: Diptera, Lepidoptera, Hymenoptera, and Coleoptera, along with Hemiptera and Orthoptera because they look cool. The next entry will feature an antlion, a specimen sent by Kit's mother in Virginia - they are extremely interesting, so don't miss it! After that I am considering featuring more Cerambycidae and a notable garden pest, but I can't give everything away.




Why are Coleoptera, Lepidoptera, Hymenoptera, and Diptera labeled "The Big Four" insect orders? Well, the quick answer: they contain the largest proportion of insects, and have the greatest diversity. Coleoptera, or "beetles", make up 1/5 of all known animal species, and 40% of all known insects. Lepidoptera contains 180,000 known species. Hymenoptera has just over 100,000 known species worldwide, while Diptera is the fourth most diverse, with 100,000 known species. All four are also holometabolous, meaning they have one sudden change from larval to adult stage, instead of the hemimetabolous insects which gradually molt until they reach their adult form. Holometabolous insects are thought to have an advantage because their adult and larval forms are so distinct - the larvae usually live in different habitats and have different feeding habits from the adults, so there is no competition for food or space. Also, all four are pterygotes, meaning they can fly and thus disperse and exploit a greater variety of habitats and ecological niches, contributing to their diversification. Since I also enjoy spreading insects, and the diversity among Hemipterans, here are two other favorites:

Friday, May 15, 2009

Phorid Flies

This entry isn't part of the typical "collection" posts, but I wanted to address a certain topic. I greatly dislike when the media oversensationalizes something which is already interesting on its own. Case in point: Phorid flies as parasites of ants. It is a very fascinating parasitoid, and the title used for the article is "Parasitic flies turn ants into zombies." In a way it is technically true, but it gives a very hokey description of a neat process. Also, it is misleading in its topic, suggesting in the article that the maggots "control ant populations and the ant's movements," almost in a science fiction-y horror way. Thankfully, one of the scientists sets the record straight by saying, "I wouldn’t use the word 'control’ to describe what is happening. There is no brain left in the ant, and the ant just starts wandering aimlessly. This wandering stage goes on for about two weeks."

I learned about this parasitoid in my Insect Ecology course, and what happens is a Phorid fly attacks an ant, and lays an egg in the thorax. The larvae hatches and moves up into the ant's head, eventually consuming the brain and decapitating the ant (it dies and its head falls off). While it is being consumed, sure, the ant wanders around aimlessly, but that is really no surprise - insects can wander around for a while without heads or all their limbs, or with crushed body parts. The head capsule serves as protection for the larvae as it develops and eventually it emerges as an adult fly. Adding a sci-fi/horror/fiction aspect to it diminishes the true awesomeness of real-life nature.

Information about family Phoridae, aka Hump-Backed Flies:

These small flies are recognized by the humpbacked appearance, special veination of the wings, and laterally flattened hind femora. They also run in a very erratic fashion. The adults are common in habitats like decaying vegetation, and the larvae live in a variety of places: decaying animal or vegetable matter, fungi, or they are internal parasites of other insects. Some even live in the nests of ants or termites, and have reduced or absent wings.

Thursday, May 14, 2009

Arctiidae part 2

A second moth has emerged, which this time was able to fully pump its wings and looks much better. I suspect it is a male, because the female had non-feathery antennae and was laying eggs - more elaborate antennae is necessary for males to find females, as females release pheromones to attract mates. Also, the abdomen and hind wings are less pink, but that may simply be due to the lack of hemolymph in the female. Here are the pictures, which are much nicer compared to the other specimen.





Lepidoptera; Noctuoidea; Arctiidae; Arctiinae; Arctiini; Gramma nevadensis
Common Name: Nevada Tiger Moth

I am more confident in the identification now that the wings are more inflated and the color and markings are more accurate.

Wednesday, May 13, 2009

Cantharidae

I found this beetle flying around some purple thistle on my recent trip back to Northern California. He is a pretty common specimen, a soldier beetle (family Cantharidae). Soldier beetles are elongate, soft-bodied beetles that reach up to 15 mm in length, and are similar to lightning bugs, but their head protrudes beyond the pronotum (shield-like structure on the thorax) and they do not have light-producing organs. Usually the adults are found on flowers, and the larvae are predaceous on other insects.



Coleoptera; Polyphaga; Elateroidea; Cantharidae; Pacificanthia consors
Common Name: Brown Leatherwing Beetle

Here is another picture of a cantharid beetle, but it is Cultellunguis perpallens sanctaeclarae thanks to the good people at bugguide.net - it appears they have some soldier beetle experts there, to get it down to subspecies.


Reduviidae

This specimen is a member of the family Reduviidae, which includes assassin bugs, ambush bugs, and thread-legged bugs. They are predaceous bugs, and are fairly common. They are often blackish or brownish, but some are brightly colored. They have an elongate head, which is restricted behind the eyes. An important keying characteristic is that they have a three-segmented beak which fits into a groove in their chest (prosternum). The abdomen is also wide, and extends beyond the lateral wing margin.







Hemiptera; Heteroptera; Reduviidae; Rhynocoris ventralis
Common Name: Assassin Bug

Because they are powerful predators they can inflict painful bites if disturbed, but if they are preying on humans, their bites may be painless from the chemical they release as they feed. Within this family there is also the genus Triatoma, which are assassin bugs that feed on human blood. They are commonly known as "kissing bugs," or "Mexican bed bugs." In South America and Mexico, members of Triatoma are a vector for the protozoan Trypanosoma cruzi, which is responsible for Chagas disease. For more information, see my medschool blog. Kissing bugs can look similar to the above pictured Rhynocoris ventralis, but kissing bugs have a longer, narrower "nose," hence the name "cone noses" for Triatoma.

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.

Tuesday, May 12, 2009

Arctiidae

A while ago I posted pictures of woolly black/orange caterpillars. A few weeks ago they stopped eating so I left them be to see if they were preparing to pupate, and when I returned from the cruise, two of them had pupated. Now, a total of four have pupated, one has hatched, and the other two caterpillars simply had not eaten enough to proceed to metamorphosis and died. I was correct in my estimation that they are from family Arctiidae, however the genus was incorrect - I was linking them incorrectly to a much larger larvae. At any rate, here are the pictures. On top we have the pupa, then various angles, and bottommost we can see all the eggs she has been laying. I do not know when she hatched, so she may have hatched a long time ago and due to not mating is now unloading all her unfertilized eggs. Her wings also do not look fully pumped with hemolymph, so it is hard to key as her wings may look different if they were fully inflated. As such, I have only identified her to genus, not species. I will further identify once I have another moth hatched.







Lepidoptera; Noctuoidea; Arctiidae; Arctiinae; Arctiini; Grammia
Common Name: Tiger Moth

There is some speculation that the genus Grammia is named so from the latin "grammus", which means marked, or in reference to the the Grammus mountain range. Both could refer to the markings on the wings, which are rather triangular. The family Arctiidae contains tiger moths, footmen moths, and wasp moths. The subfamily Arctiinae contains tiger moths, which are very common. These moths are primarily nocturnal, and their larvae are the "woollybear" variety. Cocoons are largely made from the body hairs of the larvae. The tiger moths of Grammia have black front wings with red or yellow stripes and the hind wings are usually pinkish with black spots.

Tuesday, May 5, 2009

Raphidiidae

This is a specimen of the (sub)order Raphidioptera, family Raphidiidae. There is some debate as to whether snake flies should be separated into their own order or remain a suborder. There are 17 species of the genus Agulla and 2 of Alena, which are distributed through western North America from Texas and California up to Alberta, Canada. They are distinguishable most easily from the other family in Raphidioptera by having an ocellus, while the family Inocellidae does not have ocelli. Ocelli are light-sensitive pseudo-eyes commonly found on insect foreheads which help them detect movement. Another difference between Inocellidae and Raphidiidae is that inocellids are larger than raphidiids, and may have longer, thicker antennae.





(Neuroptera); Raphidioptera; Raphiidae; Agulla
Common Name: Snake Fly

This snake fly was found in La Verne, CA. Snake flies are able to raise their heads above their bodies in a snake-like, earning them their name. The adults are predaceous, but only catch small, weak prey. The female has a long ovipositor and lays her eggs in clusters in crevicies in bark, and hte larvae are usually under bark. Larvae are also predaceous, feeding on aphids and caterpillars. Here are some live pictures taken on May 6 of a second specimen found in Contra Costa County, CA.

Curculionidae

The pictures below show a beetle from the family Curculionidae, which includes snout beetles and true weevils. They are found almost everywhere, and there are more than 3,000 species in North America. Their distinguishing characteristics include a well developed snout, and antennae arising from the middle of the snout. These insects feed on living and dead plants, and many are serious pets, particularly the larvae which feed on the roots and internal tissues of plants. The adults may bore into fruits, nuts, and other parts as well.

Because the family is so big, my textbook has information on the subfamilies. The subfamily Entiminae contains the broad-nosed weevils, so named because the sout is generally short and broad. This subfamily is flightless, as the elytra are fused together and the hind wings are vestigial. They are serious agricultural pests in the southern states, and tend to live in arid habitats like the southwestern United States.





Coleoptera; Polyphaga; Curculionoidea; Curculionidae; Entiminae; Eustylini; Diaprepes abbreviatus
Common Name: Diaprepes Root Weevil

This species is originally from the Caribbean, but was found in Florida in 1964 in a nursery near Apopka. It is thought that the weevil arrived on an ornamental plant shipment from Puerto Rico. Since its introduction, it has spread all over Florida and is a serious threat to the citrus and ornamental plant industry. It has begun to spread to Texas and California, where it has been spotted in Orange County in 2005 and San Diego County in 2006. These specimens were caught in Fall of 2008 in La Jolla of San Diego County.

Monday, May 4, 2009

Zopheridae

Until recently, these beetles were members of the family Tenebrionidae. Now, they are classified as Zopheridae, Ironclad Beetles, which includes approximately 30 species in the United States. They are extremely difficult to pin because they have a very hard, thick exoskeleton, hence their name. The antennae are short and stout, and nearly all in North America are found in the western states.





Coleoptera; Polyphaga; Tenebrionoidea; Zopheridae; Zopherinae; Nosoderma diabolicum
Common Name: Diabolical Ironclad Beetle

This species ranges in length from 15mm-25mm, and color can vary from pale brown to dark gray. It is commonly found on oak and cottonwood plants, consuming fungus-ridden wood. When disturbed, they tuck in their legs and fall to the ground, playing dead.