Fresh Water Jellyfish

Craspedacusta sowerbii  - Wikipedia CC

An article in the News-Leader by Francis Skalecky introduced me to fresh water jellyfish.  Craspedacusta sowerbii is an Asian species of jellyfish accidentally introduced into North America.  According to Freshwaterjellyfish.org - (yes they do have their dedicated website) they are now found in 44 of the lower 48 states.

C. sowerbii jellyfish are small, reaching the diameter of a quarter. They have typical jellyfish features, an umbrella with stringy tentacles attached to the edges. These contain cnidocytes, specialized stinging cells which they use to paralyze their prey, macroinvertebrates and small fish.

They are easy to miss as they are somewhat translucent. Their gonads on the underside may be the first thing spotted before making out their overall shape.  Their lifecycle is difficult for me to grasp, involving podocysts, polyps and frequent asexual reproduction explained below.

"A tiny, stalked form of the jellyfish (the polyp) lives as colonies attached to stable underwater surfaces such as rooted plants, rocks, or tree stumps. The microscopic polyp colonies feed and reproduce during the spring and summer months. The polyps reproduce asexually. Some of their offspring are the jellyfish that can be seen at the surface. The "jellyfish" or medusa reproduce sexually. Fertilized eggs develop into planula larvae which eventually settle to the bottom of the pond or lake and develop into polyps. However, in the United States, most populations of jellyfish are either all male or all female, so sexual reproduction may be rare."  Freshwaterjellyfish.org

The polyps contract in winter forming podocysts or resting bodies which may explain how they have spread to isolated ponds and water bodies, possibly transported by aquatic animals and birds.*   They may be suddenly found in large numbers one year with none the following years.  In some cases they have totally disappeared from a lake.

Although they have stinging cells, there are mixed reports on whether they can sting us.  Many people report handling them with no discomfort while others report mild itching and red spots or a slight numbness. Either way, they appear to be nothing to worry about while swimming in Missouri waters.

* Freshwaterjellyfish has a very detailed FAQ including caring for them in an aquarium.  Although not specifically mentioned, this must be a possible way of spreading them by compassionate dumping of aquarium contents. 

Phorid Flies

Phorid fly from our sink

This may be the smallest fly in your house that you have never seen. Occasionally I will see tiny dark insects, 4mm long, darting around in jerky movements in the kitchen sink by the compost container. They were impossible to photograph while darting around, never flying away.  I finally caught one in a small container and tossed it in the freezer - yes, my Master Naturalist live-in editor is extremely tolerant.

Under magnification I was surprised to see one pair of wings typical of the order Diptera, and impressively long legs.  Chris Barnhart identified them for me as flies in the family Phoridae.  They are lovingly referred to as scuttle flies, coffin flies or laboratory flies.  The scuttle refers to their habit of darting around to escape rather than flying away.

As you might guess, many species eat decaying materials including some that can persist in a sealed coffin for long periods of time.  They are commonly found around kitchens, sinks and in laboratories which house research animals.  Many Megaselia species are found feeding on fungi.  The "world's smallest fly", Euryplatea nanaknihali (0.4 mm, the size of a grain of pepper), is a phorid fly. 



The most interesting group is Apocephalus (apo - away from, cephalus - head).  Many of these species are known as ant-decapitating flies.  They will lay their eggs on ants' abdomens.  When their larvae emerge they move up to the head, feeding on it until the ant's head until it falls off, sometimes while the ant continues to move.  On the other hand, members of the genus Dohrniphora actually will bite the ant's head off and haul it off as seen on this video.

While we may not have a lot of sympathy for ants, bees are another matter.  A. borealis lays its eggs on bumblebees and wasps, with the larvae moving into the bee's head.  The parasitized bee has been called a "Zombie Bee" because of its tendency to act crazy and fly at night before dying.  About a week later the flies emerge, decapitating the bee.  Last year attacks on honey bees were confirmed, also documenting the fly can transmit deformed wing virus and Nosema ceranae, suspected factors in Colony Collapse Disorder.

When compared to others of the order Phoridae, our occasional visitors are rather benign.  I guess I will have to learn to put up with them, especially since I am too slow to squish them.

Hummingbird Tongue II

Blue-Tailed Hummingbird - Honduras - Courtesy Robert Gallardo

Back in May in Hummingbird Tongue we discussed the new findings of how a hummingbird's tongue worked based on new postmortem studies.  To quote from that report:

"The hummingbird has a forked tongue which is lined with hair-like extensions called lamellae. When inside the flower, the tongue separates and the lamellae extend outward. As the bird pulls its tongue in, the tips come together and the lamellae roll inward. This action traps the nectar within the tongue."

New studies have expanded our knowledge of the physics involved in fueling a hummer, functioning as a tiny elastic pump. Using tiny glass tubes with artificial nectar, researchers made high speed videos of 18 species of hummingbirds in Connecticut, Texas, California, Ecuador, Columbia and Brazil.

"We show that the tongue works as an elastic micropump," the researchers said. "Fluid at the tip is driven into the tongue's grooves by forces resulting from re-expansion of a collapsed section" of the tongue closer to the mouth.  This fast technique allows the bird to drain between five and 10 drops of nectar from a flower within 15 milliseconds (about 100th of a second)," Rico-Guevara told Livescience.com

The part of the mouth closest to the beak expands, drawing in fluid which is then pumped into the throat.  Even more incredible, it involves the tongue structure alone, not involving any muscles or nerves.  Studies like this only make me wonder what we will learn about the physics of bugs that can suck the juice out of a stiff plant stem, or more personally, a mosquito blood out of my skin.

Photograph above is from our friend Robert Gallardo who has written Birds of Honduras.  He guides birders through Honduras which is the winter home of 60 of our Missouri migratory birds, especially warblers.  More information at Birds of Honduras.

Urban Swifts

Chimney swifts - Richard Crossley CC

We will be posting a lot about chimney swifts over the next year but I felt this issue couldn't wait for the calendar to catch up. 

I am reprinting Jim Fossard's letter to the editor in today's News-Leader as an introduction to the problems that swifts face as we "clean up" downtown Springfield as well as historic structures in all our cities.
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I have been impressed by the development in downtown Springfield, with the “Sky 11” and “The U” loft projects, but one unfortunate, but easily fixable, casualty of this development was the loss of a really great chimney swift tower in the form of a ventilation chimney on the southeast corner of McDaniel Building, now “The U” lofts.

Hundreds of chimney swifts would congregate every evening to roost in that chimney, much to the delight of downtown residents and customers, who would marvel at their acrobatics just as the sun set. Chimney swifts migrate to North America from the Upper Amazon basin, Bolivia and Peru in the spring. Unlike most birds, chimney swifts are unable to perch or stand upright and must have chimneys or similar structures in which to roost and raise their families. As summer draws to a close and the swifts have finished raising their young, these fascinating aerial acrobats begin to congregate in communal roosts prior to their migration in the fall. Some roosts may consist of an extended family group of a half a dozen birds or so, but the larger sites can host hundreds or even thousands of swifts.

Looking around downtown Springfield, there are several capped chimneys that would make excellent habitat for chimney swifts, which are unfortunately in a steep decline in North America because of the lack of chimneys in buildings and homes. It would be wonderful if those chimneys could be uncapped, at least for the warm months of the year. Residents and visitors to the area would really get quite a show during this time of the year and it would be a draw for businesses with visitors who enjoy this aerial display. If you have never seen such a display, you are missing one of the wonders of nature.

Jim Fossard is a member of Greater Ozarks Audubon Society with a special passion for swifts.  More on these projects later.

Drones and Conservation

Civil Drone FOX-C8-HD AltiGator- Wikipedia

Love them or hate them, drones are a hot topic throughout the world.  There is even a website devoted to the topic, conservationdrones.org.  As with many new drugs, first "it's a miracle cure" but a short time later "it will kill you!"  Now we are finding concerns about the use of drones in wildlife studies.

Drones are now used to monitor seabird populations, monitor elephant habitat, study marine habitat in Belize, and monitor wetlands in Scotland.  The greatest cause of mortality among the US Fish and Wildlife employees is small plane crashes during aral observation missions.  Retired military drones are now sparing their biologists hazardous plane flights while monitoring volcanoes, studying flood zones and tracking endangered wildlife.  In the tropical forests drones patrol to detect illegal logging.

The use of drones to monitor African wildlife and catch poachers has taken off but has attracted controversy.  Engineering and Technology Magazine has a major discussion of the issues including bans by many African governments.

With familiarity comes contempt as we start to recognize the downsides of this new technology.  Airline pilots are not the only mammals frightened by the proliferation of drones, they also bug the bears.

A report in  Discovery.com describes the results of a project which monitors bears.  They were studying bears in northern Minnesota, equipping them with GPS collars and cardiac biologgers capable of reporting their location and heart rate.  They logged 18 flights of five minutes each and noted that the bears did not seem bothered by the drones.  However their monitors showed a different story.

""Some of the spikes in the heart rate of the bears were far beyond what we expected," co-author Mark Ditmer of the University of Minnesota, St. Paul, said in a press release. "We had one bear increase her heart rate by approximately 400 percent -- from 41 beats per minute to 162 beats per minute. Keep in mind this was the strongest response we saw, but it was shocking nonetheless."

Another thing that bugs bears are ticks.  We have seen ticks on bears which have been trapped for collaring but now MDC is studying the tick burden in different seasons.  The initial summertime counts have gone from 200 to 1000!  That gives a whole new meaning to "ticked off."

Count the small white dots of engorged ticks

Some years back we had the opportunity to drift over elephants in a hot air balloon over the Serengeti.  These gentle giants were able to walk within a few feet of a Range Rover full of camera laden tourists but our balloon 100 feet overhead caused them to panic, trumpeting and breaking into a run.  Although they were the largest animals, seemingly oblivious to a wide variety of predators, a new threat from above spooked them.  We assume that wildlife ignores our aerial surveillance by planes and drones.  It seems that we have a lot to learn about wildlife.

Long-bodied Cellar Spider

Spreading out on the wall - REK

After years of watching these leggy spiders crawl all over the bathroom in our creek house, I thought it was time to give them their day in the sun.  After all they spend the rest of their lives sequestered in dark, damp places asking for nothing and bothering no one, unless it is a house guest too polite to mention them.  For the most part they just hang on a wall or slowly explore the tile floor, looking for tiny pests that we don't even know exist.

This is the Long-bodied Cellar Spider, Pholcus phalangioides, the most common of the Pholcidae or cellar spiders.  They have a number of common names including daddy long-legs spider, granddaddy long-legs spider, carpenter spider, and vibrating spider. Their bodies are 5-8 mm long, (less than 1/3") and their leg are 8 times longer.

"Daddy Longlegs" Crane Fly- Six legs of an insect  - REK

Crane fly - Limonia - REK

Their "daddy long-legs" name is appropriate but can be confusing.  This common name is also applied to both harvestmen of the Opilione class and to crane flies which are sometimes mistaken for giant mosquitoes.  Crane flies have 6 legs like all insects and wings typical of all the Diptera (true flies).


Long-bodied spiders have three distinct body parts (head, thorax and abdomen) while the Opiliones (harvestmen) have the head and thorax fused into one small part frequently making their bodies appear oval.  Both have eight legs typical of the Arachnids.

Harvestman - REK

Long-bodied Cellar Spider - REK

They originated in the sub-tropics but are now found on every continent, probably traveling along with the commerce of humans.  They do not tolerate cold but have found their niche in warm human habitats.  In their original lands they reproduce annually in the warm season while in our house it is always the season to reproduce and life is good.

Skull shaped head with two sets of three round eyes tightly clustered together - REK

Because of the shape of their thorax they are also commonly called a "skull spider."  Another defining characteristic of various spider species is the placement of their eyes.  In this case there is a set of three round raised eyes clustered on both sides of the head as well as another pair in front.

Female with egg case - Olei CC- Wikimedia

A female produces 20-30 eggs which she will patiently carry around in her pedipalps until the young hatch.  The young will molt six times before they reach maturity

Mother and babies - Luis Fernández García via Wikipedia

Their webs are irregular, messy but very small, tending to cling to a wall or other horizontal surface.  When they perceive a threat they start vibrating on their web, making them harder to see, thus the "vibrating spider" name.

Long-bodied spiders have very weak venom and are barely able to pierce human skin, with only a temporary discomfort.  On the other hand, they are considered beneficial as they are predators of many venomous spiders that are threats to us.  As we see an occasional brown recluse in the nooks and crannies, letting these leggy creatures patrol the house is a small price to pay.
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Recent studies have shown that this species is wide spread in Europe and North America but can have differences in DNA is small "islands" such as apartment buildings.  In Darwin Comes to Town Martin Schäfer of the University of Bonn studied the cellar spiders (Pholcus phalangioides)in buildings in five European cities.  "He discovered that the spiders living in different rooms within one building jointly form a single gene pool, but that each building is a separate gene pool: the spiders move chambers, but rarely move house." *
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* Schilthuizen, Menno. Darwin Comes to Town: How the Urban Jungle Drives Evolution (p. 115). Picador. Kindle Edition. 

Milkweed Bugs

We had a colony of Large Milkweed Bugs covering a small cluster of milkweed.  They are not a serious threat to the plants in general but this plant was being saved as a source for seeds.  I received permission from my editor to study them for several days before they were removed.

As you might guess by the name, Large Milkweed Bug, Oncopeltus fasciatus, there is also a Small Milkweed Bug which we observed in upstate New York recently.  Both have the bright orange aposematic coloration warning that says "I am full of milkweed toxin- consume at your own risk."

Small Milkweed Bug

Large Milkweed Bug

All five instars of nymphs clustered together

"The milkweed bug undergoes incomplete metamorphosis. The nymphs look like adults but do not have full wings and their color pattern is different. They have five instars before they reach adulthood. Black wing pads appear early in their development. Eggs are a light lemon yellow changing to a reddish color. Incubation period is about four to five days. Each molt lasts five to six days. An adult will live for about one month. The insect overwinters as an adult." Missouribotanicalgarden.org

Milkweed bugs suck the liquid from the plants using their long proboscis which extends down along the abdomen.  The toxic chemical they ingest from milkweed is transmitted into the eggs. They are extremely productive, laying 30 eggs a day and up to 2,000 in their lifetime.  This trait makes them ideal subjects for insect laboratory research because they also have a short life cycle and are easy to manipulate.








 

There are several subtle (to me) anatomical differences between the male and female.  The easiest way to tell is to compare a mating pair, because the female tends to be larger than the male. Since copulation lasts for up to 10 hours there are usually multiple pairs on a single plant. 

The large milkweed bug, Oncopeltus fasciatus, is a good species to study for an understanding of hemiptera ("true bugs").  They are said to be easy to raise with a short life span, making them the perfect "lab rat" for an entomologist or a classroom full of 5th graders.  They can be fed cracked sunflower or watermelon seeds.*  That said, I followed the directions carefully and all of mine went on a hunger strike and died.  Obviously I am not up to the 5th grade level.

* Instructions for raising milkweed bugs are available at this link.

A "must watch" video from Cornell discusses how Monarch caterpillars handle milkweed defenses. 

Another Missouri Invasive Species

Megachile sculpturalis at Springfield Botanical Gardens - Chris Barnhart

An unwelcome visitor was seen visiting the flowers at the Springfield Botanical Gardens this week, and for a change it wasn't a "Canada" goose. Chris Barnhart sent this picture of giant resin bees, Megachile sculpturalis, an Asian species probably accidentally introduced with some commercial product before first being discovered in 1994.

"The giant resin bee (Megachile sculpturalis) is so named because it is larger than most other leafcutter bees, ranging in size from 14 to 24 mm long, and because it uses its strong jaws to collect plant resin to seal the cells in which it lays eggs. This bee is native to Asia, but was inadvertently transported to the United States in the 1990's, where it was first identified in North Carolina in 1994. It is now present in most of the southeastern United States. This bee resembles bumble (Bombus spp.) and carpenter (Xylocopa spp.) bees, except that it lacks both the hairy abdomen that is present on bumble bees and the shiny abdomen that is present on carpenter bees."   EOL.org

By my definition, M. Sculpturalis is an exotic species that hasn't earned the title of "invasive species" yet, although that is somewhat a matter of taste.  I would define invasive species as exotic plants or animals that are creating damage and economic costs to society.  Researchers have reported seeing it aggressively evict native eastern carpenter bees from their nests. The frequency of these episodes and their effects on the ecosystem is not known.

From  iNaturalist.org

Although it resembles a carpenter bee, its strong jaws are not capable of boring into wood so it nests in cracks of wood walls and in holes created by carpenter bees or other wood boring creatures.  It is too early in their North American career to know if they will affect the carpenter bee population by competing for nesting sites (bad?).  These carpenter species are not on most homeowners list of favorite insects although they are important pollinators.

The female M. sculpturalis constructs its nest in a preexisting cavity by bringing in mud and rotten wood particles that are then glued together with sap and resin from trees.  Next she collects pollen on her hairy thorax (good!) and places an egg on it before sealing the cell and starting again.  The offspring live on the pollen over winter, pupate and then emerge in the spring.

Several bees may nest around a house which can be threatening but they are no danger.  The males have no stinger and the females will only sting if you hold them in your fist.  This is not a good idea with any bee and anyone trying it probably has earned a sting.

Modifying a Mosquito

   Photo by Muhammad Mahdi Karim/Wikipedia,

Sitting on the deck above the creek, swatting mosquito's, it is easy to wish for a scientific breakthrough that would eliminate all mosquitoes or at least modify them so they didn't transmit disease.  It looks like some of this could occur during our lifetime but an article from Scientific American reminds us to be careful what we wish for.

Scientists now have the ability to "edit" genes in insects.  Not only are there techniques that might someday prevent a mosquito from carrying malaria, but there are techniques that could potentially expand a given mutation throughout the whole population of insects.  Sounds good so far.

Then we come to the Pandora's Box effect.  Suppose an altered species escapes the lab before we know all the consequences of the mutation.  In new pharmaceuticals, the benefits are proven long before all the side effects emerge when a drug is used by a much larger number of people.  And this is in a case where we can stop prescribing the drug to limit the damage to a small group of humans.  When you consider altering species in the wild, the effects on the food chain, predator-prey relations, and the spread to related species, the consequences become really scary.

Yellow fever vector Aedes aegypti -Photo by Muhammad Mahdi Karim

Consider for a moment a gene that could stop female mosquitoes from biting us.  One that could spread through the whole world-wide mosquito population.  Since they require blood of humans or "lesser species" of mammals -insert your own definition here- the entire mosquito population conceivably go extinct.  However there are over 3,500 species world wide, most of which pose no danger of disease or even of biting us.  They are food for insects up and down the food chain, although no one species is dependent upon them.  Some are even incidental pollinators!

Then there is the risk of a genetic mutation that could jump to other species.  It only gets more speculative (and more scary) from here.  Way too many unknowns.

The Scientific American article emphasizes the need for fool-proof containment of the modified insects to the lab until we know all the ramifications of their future release.  Unfortunately we are unlikely to know all the risks for years after a release and our ability to secure labs has been dicey to say the least.  Remember that even recently government labs accidentally distributed live anthrax to nine different locations, and this was in from a highly secure facility.  There are no easy answers.

Thanks to "Daddy-Dave" Shanholtzer for the lead.

Snake Fungus

Black Rat Snake with O. ophiodicola granuloma -   Figshare.com

A deadly fungal disease in snakes is gaining more attention recently.  Ophidiomyces ophiodiicola is found in the soil but only in the last few years has it been associated with disease.  It has somewhat similar characteristics to white-nose syndrome in bats.  While occupying different niches both fungi share many of the same enzymes.  These enzymes allow the fungus to persist in the soil, metabolizing similar nitrogen and carbon sources.  Although surviving on dead matter it can also attack a live snake.

Ophidiomyces ophiodiicola -  Figshare.com

According to researchers at Illinois.edu, snakes affected by snake fungal disease include northern water snakes, eastern racers, rat snakes, timber rattlesnakes, Eastern massasaugas, pygmy rattlesnakes and garter snakes.  So far this has been found only in some eastern states, but some cases have been found in Tennessee and Illinois which abut Missouri.

At this time, researchers are uncertain if this fungus can attack healthy snakes or whether it only affects snakes with poor nutrition and impaired immunity.  Also unknown is why this fungus has only been causing disease in the last few years.

* There is far more detail in Chrysosporium-Related Fungi and Reptiles: A Fatal Attraction reported in PLOS.

Which Damsel ? - My Distress

This damselfly showed up on a branch just off of our deck.  I enjoy the challenge of identifying insects but a long visit to OdonataCentral and other sites convinced me that I was out of my depth.  I sent it to fellow amateur naturalist Jon Rapp of Columbia who responded in an hour with my answer.

Jon pointed out that it is difficult to identify because females are hard to understand.  Yeah Jon, tell me about understanding females!  Actually to use his words:

"Now then, the first two aren't as easy because they are female. Some guides don't even bother to show female damsels. They tell you that your best bet is to find the nearby males and ID those because so many females look alike. Given that, I think I can ID this one as a female Dusky Dancer - Argia translata. Females of this species are very similar to female Powdered Dancers. However, your view shows the striping on the segments S8-10 which Dusky's have and Powdered don't. So I think you're safe with this ID. (But keep in mind I am no expert!)."

Few people would claim to be an "Odonate expert" but the fact is that much of what we know about frequency and distribution of Odes (dragonflies and damselflies) and insects in general depends upon a core of "citizen scientists" who find and study a class of insects or other animals and diligently report their findings to scientific databases such as OdonataCentral and BAMONA.

With modern pocket cameras or even cell phones it is possible to get good insect photographs.  An example from this online key requires an examination of the hairs on the legs. "Are the spines on the 2nd joint of the legs twice as long as the spaces between the spines? Then your damselfly is a Dancer belonging to the genus Argia." By adjusting the camera angle in another photograph to get a better background and cropping to enlarge the legs, you can make the call - it is a Dancer.



Identification of insects to the species level often depends on identifying small differences in body parts that otherwise would escape notice.  An example is Jon's statement "striping on the segments S8-10" as seen above to separate a Dusky from a Powdered Damselfly.

I would encourage you to try finding your own answer using field guides and online resources.  You may find your inner naturalist.  We have listed some sources in the "Resources" link found at the top of the right hand column above.  WARNING- IT CAN BECOME ADDICTIVE!

Black Widow Meal

Black Widow hanging upside down from web with egg case - REK

Lisa Berger recently found a black widow spider in her window. Like any seasoned naturalist, she let it be and followed its progress over several days. When it captured an insect, she filmed videos of the carnage.

Wrapping up dinner - Lisa Berger

While their web detains its prey, like most other spider species widows administer the coup de grâce by envenomation. Their chelicerae (jaws) are hollow and connect to venom glands at their base. Spiders have a very narrow intestinal tract that only accommodates liquids. It even has two filters to keep out solid particles. Digestive juices are injected into the prey, then predigested nutrients are sucked up into the intestine.

The "kiss"

The prey was bitten several times and it took a while to die. In this video you can see the final "kiss" and the spider starting to use its back leg to drag it away. It ended up in the web funnel where the widow could digest its juicy meal in relative safety.




Black widows hang upside down in their low lying web, exposing their bright red hourglass. This is thought to be an aposematic coloration, advertising their toxicity to hungry birds. Since insects see a different light spectrum than birds, it probably doesn't put off the spider's prey according to a recent study.

More on Black Widow's mating dance is in this previous blog.