Loxosceles rufescens (Dufour, 1820), the Mediterranean recluse spider
Last month, I found this spider in Seitz Hall on the campus of Virginia Tech where we house the Virginia Tech Insect Collection. At first glance, I thought it was a Brown recluse spider (Loxosceles reclusa Gertsch & Mulaik, 1940), but sent the specimen to Matt Bertone at North Carolina State University, who determined it was the Mediterranean recluse.
The Arthropod Museum in the Department of Entomology at the University of Arkansas has a nice article about the two species and how to tell them apart. The Mediterranean recluse is an introduced spider with origins in the Mediterranean region, but it is well established in many places. Another introduced species of arthropod from the Mediterranean region is the fleet-footed House centipede Scutigera coleoptrata (Linnaeus, 1758). As both are predators, I imagine them battling it out for the delectable cockroaches and silverfish prey running around.
Scutigera coleoptrata (Linnaeus, 1758), the House centipede
Cedar glade mimic millipede
This millipede is the species Brachoria cedra Keeton, 1959 from the The Cedars Natural Area Preserve in Lee County, Virginia. The Cedars Preserve is a wonderful limestone glade habitat, and it gets its name from the Eastern redcedar growing in the area (Juniperus virginiana L.). The millipede is officially listed as a state threatened species in the state.
Enoclerus ichneumoneus (Fabricius, 1776)
Larva of the Net-winged beetle, Caenia dimidiata (Fabricius, 1801)
This is the larva of Caenia dimidiata, a Net-winged beetle of the family Lycidae. The top image shows the dorsum (back) of the beetle, and the bottom is the venter (underside). The adult beetle has a striking orange and black appearance. Many lycid beetles produce noxious lycidic acid or pyrazine and they warn potential predator of their toxicity through conspicuous coloration (Eisner, 2005). The strange protuberances on either side of its body segments are composed of cuticle and serve an unknown role. The beetle’s head is bizarre and possesses stubby antennae and reduced mouthparts.
- A high-res version of the beetle image is linked here (9.2 MB).
- Eisner, T. (2005). For love of insects. Harvard University Press.
- Thanks to D. Hennen for collecting it, and J. Cicero for identifying the species.
- There are no images of C. dimidiata larvae online, so feel free to use this one anyway you see fit since it’s in the public domain (CC0)
A new species of therophosid tarantula: Aphonopelma mareki
This week a tarantula from the desert southwest was named after me. The species was named by my colleagues Chris Hamilton, Brent Hendrixson, and Jason Bond in the journal ZooKeys (doi: 10.3897/zookeys.560.6264).
A few years ago on October 27, my wife Charity and I (and our dog) took a backpacking trip to West Clear Creek Wildnerness in Yavapai County, Arizona. It was a beautiful place and an excellent recommendation by Charity.
West Clear Creek Wilderness, Arizona
During the hike, we backpacked, camped, swam, and took day hikes (and night hikes). One evening, we hiked out from the camp and found a neat black tarantula with sandy blonde highlights. I knew it wasn’t the common and widespread species Aphonopelma chalcodes, so I collected it for my spider colleagues. (Tarantulas are easy to collect because they’re relatively docile—you just touch their back legs and they’ll crawl right into a peanut butter jar.) The spider turned out to be a new species, and I was truly honored to have it named after me. The article that contains the new species is 340(!) pages long, and includes taxonomic treatment of all 55 species of the genus Aphonopelma. It’s was a huge undertaking and a wonderful published work.
The theraphosid tarantula Aphonopelma mareki in nature
Death’s-head Hawk moth, Acherontia atropos (Linneaus, 1758). D. Descouens CC BY-SA 3.0
Join entomologists from Virginia Tech and celebrate National Moth Week! Come out to the university farm and discover insect biodiversity and nighttime nature. We’ll be at Kentland Farm at 9PM this Thursday, July 23. We’ll set up an insect-alluring mercury-vapor lamp and UV black light.
This year’s National Moth Week is celebrating the moth family Sphingidae, which includes the hawk moths, sphinx moths, and hornworms. Pictured above is a member of this family from France. It’s a close relative to our Tomato hornworm (Manduca quinquemaculata) here in the United States. Sphingid moths are fascinating insects with a superb ability to fly. Often displaying “swing-hovering”, sphingids have the agile ability to make rapid lateral movements. This flying behavior may have evolved to evade their sit-and-wait predators hanging out in the flowers that the moths visit to sip nectar.
The Death’s-head Hawk moth, which is distributed throughout Europe and Africa, possesses a skull shape pattern on its thorax. Here’s a picture of one specimen with a particularly excellent skull. Acherontia atropos has some fascinating behaviors. The adults go on nighttime raids of bee nests for honey and they make a peculiar squeaking noise if disturbed (thanks Rhea for sharing that factoid!)
- Directions: enter Kentland Farm’s main entrance and go west past the UAV strip. We will be south of the road in the driveway of the old house on Kentland’s campus. The exact latitude and longitude are: 37.19533, -80.58061 A link to the location is at:
This week, we published a study documenting the rediscovery of the millipede Xystocheir bistipita, which turns out to be bioluminescent and a species of Motyxia, the Luminous mountain millipedes (Marek & Moore, 2015). A few folks have asked what the distribution looks like with these new data. Here’s an updated distribution of the genus including Motyxia bistipita (we transferred the species into Motyxia after determining it was more closely related to bioluminescent millipedes in the genus Motyxia). The distribution of Motyxia is overlaid on Level III USGS ecoregions.
- Marek, P.E. and W. Moore (2015) Discovery of a glowing millipede in California and the gradual evolution of bioluminescence in Diplopoda. Proceedings of the National Academy of Sciences, USA. early edition [Open access]
The bioluminescent jellyfish Aequorea victoria is the source of green fluorescent protein (GFP) Credit: Sierra Blakely, Wikimedia Commons
My research team, which is funded by the National Science Foundation (NSF), explores bioluminescence—the biological production of light by natural chemical reactions. Specifically we focus on the evolutionary origins of bioluminescence in Motyxia, the only millipede genus in California that is bioluminescent.
Interestingly, Motyxia are blind, and so their visual signaling can only be seen by members of other species, such as predators. In addition, Motyxia produce hydrogen cyanide, an extremely poisonous gas as a chemical defense. Some of our research indicates that Motyxia’s bioluminescence serves as a warning signal to deter nocturnal mammals from eating these highly poisonous millipedes.
By helping to reveal the evolutionary origins of bioluminescence, we can better understand and investigate how other complex traits arise in nature. In addition, bioluminescence research has a history of offering many proven and potential societal benefits in fields ranging from national defense to medicine. Some examples:
- Bioluminescence is also called “cold light” because the biochemical reaction that generates bioluminescent light is typically more than 90 percent efficient, meaning that only 10 percent of bioluminescent chemical energy is wasted as heat. By contrast, incandescent light bulbs are only 10 percent efficient! We could enhance the efficiency of our lighting systems by designing them to mimic natural bioluminescent reactions.
- The bioluminescent underbelly of the marine bobtail squid blends with background light from the water’s surface and so decreases the squid’s vulnerability to attack from predators dwelling below it. This natural camouflage offers the potential to inspire luminescent (glow in the dark) hulls for warships. The U.S. Navy is currently studying marine animals that use bioluminescence.
- All humans spontaneously release ultra-weak photon emissions and generate light through processes that are similar to bioluminescence in other animals. However, cancerous cells emit more light than do normal cells. This difference suggests that human luminescence may be used as a clinical tool to help diagnose illness and pinpoint the exact locations of cancerous cells.
- NSF-funded biologist Osamu Shimomura wanted to know what caused the jellyfish Aequorea victoria to glow green. One protein he found in the jellyfish, called green fluorescent protein (GFP), has revolutionized how scientists study cells. GFP is now widely used in biological and biomedical research as a fluorescent tag to help researchers track specific biological activities, such as the spread of cancer, the production of insulin and the movement of HIV proteins. And in 2008, Shimomura along with Drs. Martin Chalfie and Roger Tsien received the Nobel Prize in Chemistry for the discovery and development of GFP.
- The enzyme that is responsible for bioluminescence in beetles is used by researchers to carry out next-generation pyrosequencing—a fast, inexpensive method for sequencing genomes. In 2008, pyrosequencing was, for the first time, used to sequence the full genome of an individual human; the human was Dr. James Watson—the co-discoverer of DNA. Also, in 2008, pyrosequencing was used to sequence the complete genome of a Neanderthal.
- Enzymes responsible for bioluminescence are used by researchers to detect ATP (adenosine triphosphate), which is an essential substance for living cells.
- A version of a light-emitting compound from the seed shrimp Vargula (a small bioluminescent crustacean) is used by researchers to measure superoxide anions, which are a critically important component of metabolic systems that are difficult to detect in nature.
- Many types of physiological processes trigger changes in concentrations of intracellular calcium ions—an essential component of biological processes. One way to track intracellular calcium concentrations is to insert into cells a type of photoprotein known as aequorin, which is derived from the bioluminescent jellyfish A. victoria. Aequorin is highly sensitive and specific to calcium and—most importantly—emits light when it reacts and thereby signals calcium concentrations. In addition, it is non-toxic to most cells.
- Other photoproteins derived from diverse animals might be used someday to help understand other complex but fundamentally important biological dynamics. For example, Beroe, a comb jelly and Thalassicolla, a radiolarian, might also be used to help detect calcium ions, and Harmothoe, a scaleworm, might be used to detect iron ions.
Next time you’re up late and it’s dark outside (even better right after a summer rain), visit your local natural area—a moist gully or streamside are the best. Turn off your flashlight and allow your eyes become adjusted to the light. Blue ghosts, railroad-worms, luminous millipedes, and snail-eating firefly larvae are some of the bioluminescent organisms you might see. When you observe these fascinating organisms, consider how they emit light and why their ability to bioluminesce evolved. But importantly, just take a moment to quietly observe the nightlife and nature’s living light.
Parasitoid wasp in the family Braconidae (genus Asobara)
Parasitoid wasp in the family Pteromalidae (genus Pachycrepoideus)
Jamie Wahls, grad student in Tom Kuhar’s Vegetable Entomology Lab @ VT, visited our lab again with some of his fascinating parasitoid wasps. These are images of unidentified species of braconid and pteromalid that we captured with our microphotography system. Handsome beasts.
(Canon 6D, 65 mm lens, 3x, 1/125s, f5.6 – image stack)
The toxic web of Orfelia fultoni (Diptera, Keroplatidae)
While on a collecting trip to the Pisgah Mountains of North Carolina, we found the fly Orfelia fultoni. These luminous fly larvae dotted the mossy bank of a spring and emitted a continuous blue glow. The spectrum is the bluest of any terrestrial bioluminescence, and originates from the larva’s head and tail. This luminescence has been experimentally shown to be effective in attracting insect prey (Sivinski, 1982). The fly larvae, which were about 1 cm long and translucent, appeared on the surface of the moss suspended in a web adorned with little ampules of clear fluid. In the image above, the fluid-filled ampules appear as tiny white cones, and you can see the larvae just to the right of the web in the middle of frame, you’ll have to look close. The ampules are filled with oxalic acid and when an entangled insect disturbs them, they rupture spilling the toxic fluid onto the insect prey (Fulton, 1939).
- Fulton, B. B. (1939). Lochetic luminous Diptera larvae. Journal of the Elisha Mitchell Scientific Society, 55, 289-293.
- Fulton, B. B. (1941). A luminous fly larva with spider traits (Diptera, Mycetophilidae). Annals of the Entomological Society of America, 34(2), 289-302.
- Sivinski, J. (1982). Prey attraction by luminous larvae of the fungus gnat Orfelia fultoni. Ecological Entomology, 7(4), 443-446.
- Viviani, V. R., Hastings, J., & Wilson, T. (2002). Two Bioluminescent Diptera: The North American Orfelia fultoni and the Australian Arachnocampa flava. Similar Niche, Different Bioluminescence Systems. Photochemistry and Photobiology, 75(1), 22-27.
- The adventurous blog of Danté Fenolio: anotheca.com/wordpress