Nature in Fragments: Raccoon Snoring, Tadpoles Gulping Air, Insects Fighting to the Death and More!

Summer is over and my phone is full of photos, videos and audio, so it's time for a memory dump. Dig around and see if you find anything you like ... be sure to wash your hands afterward.

Raccoon Snoring! Raccoons (Procyon lotor: Procyonidae) have a wide range of vocalizations (as many as 51 different sounds!) but I have yet to hear a raccoon snoring on the internet ... until now! Bandit is our resident raccoon. He spends his days sleeping under some rarely-used steps behind our house. We have a friendly but respectfully-distant relationship. Janet passed the steps the other day, and she thought he was growling at her. Turns out, he was just sleeping.
     Whenever I tell someone that we have a raccoon living under our steps, I get asked whether I'm concerned about rabies. Well, Bandit might have given me rabies a couple times, but a few zinc lozenges and plenty of fluids seemed to take care of it. I do feel like biting people sometimes, but no more than before I got the rabies.
     Seriously, though, raccoons are one of the four main reservoirs of rabies in the USA. According to the Center for Disease Control, 31% of wild animals with rabies in the United States are bats, 29% are raccoons, 25% are skunks, and foxes come in at about 5%. The largest reservoir in Puerto Rico are mongooses. Raccoons are probably the biggest concern in Maryland.  Still, it's hard to know what to do with the information available; it doesn't tell us the proportion of raccoons that are infected at any given time. What we really want to know is the probability of encountering a rabid raccoon. The odds are probably rather slim. A rabid raccoon only lives 1 to 3 days after becoming infectious. What happens if you're bitten by a rabid animal? Well, the CDC considers the situation to be urgent, but not an emergency. Cleaning and treating the wound is the first order of business followed by injection with rabies prophylactics, which are about 100% effective. An active infection of rabies is virtually incurable (1-3 people die each year in the US from rabies), but preventing an active infection after exposure is as close to a sure thing as you're going to get in a medical treatment. It ain't Little House on the Prairie or Old Yeller anymore, folks. (By the way, don't ever watch the movie Old Yeller, just don't do it.). According to the CDC's list of primary causes of death, you are more likely to kill yourself than to be killed by a rabid raccoon ... and you are more likely to kill yourself after watching Old Yeller.
Frogs!

I remember a rather lame horror movie entitled Frogs (1972). It was about the creatures of a swamp taking revenge on a family that abuses the environment or are otherwise jerks. I recall three main things about the movie: The frogs (toads, actually) were omnipresent but really didn't do much but hop around and disrespect people, a snapping turtle ate a lady, and Ray Milland really deserved better acting gigs. I think the following video is better than Frogs, if I say so myself.

Tadpoles Surfacing to Gulp Air on a Hot Day in July This video was taken at a small, spring-fed pond behind my house. I find the video to be very relaxing. Newly hatched tadpoles of typical frogs (Ranidae) get most of their oxygen through the skin and by small external gills. As the tadople matures, the external gills are replaced by internal ones, although the skin continues to be a very important respiratory organ. Currents passing over the internal gills are created by buccal pumping, that is, by increasing and decreasing the volume of the oral cavity. The timing of lung development varies a lot between species. Ranid frogs tend to develop lungs fairly early, long before they are actually needed. Tadpoles may not come to the surface to breath very often, even if the lungs are present and fully functional. Experiments have shown that they can complete metamorphosis without ever using their lungs, as long as the water is well oxygenated. However, as water temperature increases, the amount of dissolved oxygen that the water can hold decreases. So, on hot days, tadpoles may visit the water surface fairly often. The air temperature was in the 90s on the day I took this video, which probably accounts for the video-worthy performance of the tadpoles. I am not sure what species these are. Based on their size and number, I suspect it is Lithobates clamitans, the Northern Green Frog. Maryland Biodiversity Project.

For a more-detailed description of respiratory metamorphosis, see Burggren & Infantino (1994).

Patuxent State Park near Hipsley Mill Road Access, Early September

Lithobates sylvaticus. Wood Frog (Ranidae). This frog ranges from the northeastern U.S., throughout most of Canada and into Alaska. It occurs above the Arctic Circle. Obviously, it must have a pretty powerful antifreeze, which is the subject of a fair amount of research. It occurs throughout Maryland and, along with spring peepers, they are the first frogs to start singing in the spring. While peepers peep, wood frogs produce a sort of quack. They wander far away from the vernal ponds after breeding season.
     It was getting dark when I took this photo. I was a little disappointed with the detail, and my model held the pose just long enough for one shot. However, the result has a kind of water-color look that has grown on me. Maryland Biodiversity Project

Lepidoptera!

Late August, Southern Frederick County

Left: The day-flying Coffee-loving Pyrausta Moth, Pyrausta tyralis (Crambidae: Snout Moths), on Wild Carrot or Queen Anne's Lace, Daucus carota (Apiaceae: Carrot Family). The moth occurs from New York to Illinois in the north and Florida to Arizona in the south. In Florida, its caterpillar feeds on Wild Coffee, Psychotria nervosa (Rubiaceae), although the seeds of this "coffee" don't have caffeine and are not brew worthy in any other respect. Outside Florida, the caterpillars feed on certain composites (Asteraceae), specifically, Swamp or Purple-stem Beggarticks (Bidens connata), Dahlia species and perhaps other plants yet to be determined.
Right: A Crossline Skipper, Polites origenes (Hesperiidae: Skippers) on Red Clover, Trifolium pratense (Fabaceae: Legumes or Pea Family). Maryland Butterflies

Left: Junonia coenia (Buckeye) (Nymphalidae: Nymphalinae). Late August, Southern Frederick County. A common and very pretty butterfly in Maryland and throughout much of the United States. The wings of this individual are a little worse for wear. The larvae feed on plants in Plantaginaceae (plantains, toadflax, snapdragons) and Acanthaceae (wild petunias). Maryland Butterflies
Right: Eumorpha pandorus (Pandora Sphinx Moth) (Sphingidae). Mid-August, Univ of Maryland. A large and strangely colored moth...camouflage with a tinge of pink, very fashionable. The larva feeds on plants in the grape family, Vitaceae: Grapes (Vitis spp.), Virginia Creeper (Parthenocissus quinquefolia) and Porcelainberry(Ampelopsis glandulosa). BugGuide, Maryland Biodiversity Project

Euchaetes egle. Milkweed Tiger Moth (Erebidae: Arctiinae) on Common Milkweed, Asclepias syriaca (Apocynaceae: Dogbane Family). Early September, northern Montgomery County. Like Monarch caterpillars, the caterpillars of this species eat milkweed and sequester cardiac glycosides in their tissues to deter predators. This species likes the older leaves and the monarch likes them green, "And so between them both, you see, They licked the platter clean." The chemical is retained in the adult moths, which communicate their distastefulness to bats by emitting clicks. It is unclear whether the bats are all that deterred, however. Butterflies and Moths of North America, Bug of the Week (Mike Raupp)

Climbing Plants: Vines and Bines!

Apparently, a vine is a climbing plant that uses tendrils or suckers to support itself, while a bine uses the stem itself to spiral, loop or hang on a substrate for support. Who knew?

Yet Another Invasive Climbing Plant!

Humulus japonicus. Japanese Hop or Hops. (Cannabaceae: Hemp Family). I watched this plant for a couple weeks waiting for it to flower. I thought it might be a Wild Cucumber, Echinocystis lobata (Cucurbitaceae), but it wasn't, of course. Japanese hops is a bine rather than a vine and a close relative of Cannabis. It was introduced to the U.S. during the late 1800's from temperate Eurasia for use in herbal medicine and as an ornamental. It is still available commercially, but why?  Plants are either male or female, with the male bearing panicles of small greenish flowers (pictured) and females having the typical appearance of hops (a sort-of cone composed of tiny leaves). It can be used as an additive to beer but is not as good as common hops, H. lupulus. Japanese hops prefers rich, moist soils in sunny locations and has become an invasive in Maryland, especially in open riparian floodplains. This plant was in the news recently for creating problems for a project aimed at reforesting a floodplain of the Monocacy River near Frederick, MD. The hops climbed the sycamore saplings, topped them and bent them over. Some broke under the weight of the hops plant. Jerks.

Cynanchum laeve. Honeyvine. (Apocynaceae: Dogbane/Milkweed Family). I first mentioned this vine in the post Local Color. Part 2. I continue to be intrigued by it, but I am not sure why. A "milkweed" vine fully capable of supporting even monarch butterfly larvae. Cool. As if I needed further proof, my most recent visit to the vine revealed nymphal milkweed bugs (pictured). The flowers still smelled amazing but are virtually gone. Sad face.

Insects!

Left: Wheel Bug, Arilus cristatus (Reduviidae) a large predatory bug. Center: Banded Netwing Beetle, Calopteron reticulatum (Lycidae). The orange and black aposematic coloration advertises that the beetle is unpalatable due to at least two chemicals that it produces, one called lyctic acid. The color pattern is shared by a long-horned beetle Elytroleptus (Cerambycidae), which apparently gets it lyctic acid by eating netwing beetles, and the zygaenid moth Pyromorpha dimidiata and erebid moth Lycomorpha pholus, which seem to be palatable and are just taking advantage of the situation. Right:  Buprestis rufipes. Red-legged Buprestis (Buprestidae: Metallic Woodboring Beetles). BugGuide
  Retraction and Update!

The video below shows a large wasp attacking a cicada, Neotibicen sp. In my original post, I had assumed that the wasp was a cicada killer, Sphecius speciosus (Crabronidae). This solitary wasp stings and paralyzes cicadas and transports them to a burrow, where it provisions each future son with one cicada and each future daughter with two.  Entomologist and blog reader Dr. Al Green was puzzled at the amount of time and effort that the wasp was expending to dispatch the cicada. Cicada killers are very proficient ... think ninja and poison stiletto ... and generally wrap things up in under a minute. But the video seems more like a long episode of Big Time Wrestling. Closer inspection revealed the aggressor to be a European Hornet, Vespa crabro (Vespidae), a social wasp related to  yellowjackets. Hornets are mainly predatory and attack a wide variety of insects, including honey bees, but cicadas are at the extreme end of the size range. According to Al Green, hornets and other social wasps gnaw rather than sting their prey into submission. Large, well armored insects like cicadas thus present something of a challenge, but this one was apparently up to it.

European Hornet vs. Cicada