Monday, June 3, 2024

American Medical Leech

Photo by: K. Leeker

Many years ago, when working for the Missouri Department of Conservation, I was helping a local professor locate frog eggs in an ephemeral pond. This particular pond was located within the woodlands behind the building where I worked. After finding some eggs and wading into the water to collect them I became all to aware of what else was living in that small pond. LEECHES! I exited the water and to my surprise I found two leeches attached to my legs. I didn’t know whether to be fascinated or grossed out. Then I remembered something I was once told, “A dedicated nature enthusiasts never says “EWWW”, instead they exclaim “OHHHH, how interesting.” I did my best in that moment to be a dedicated naturalist, who other naturalists could be proud of, but the ick factor got the better of me and I quickly evicted these little bloodsucking vampires from my person. After all these years I have never forgotten that moment, which goes to show what a lasting impression these parasites can leave on our psyche.

There are nearly seven hundred species of leeches found worldwide. Leeches are found in freshwater ecosystems, a few are found in marine habitats, and rarer still are species that are terrestrial and live their lives on land. Slow-moving freshwater habitats such as streams, lakes, and ponds are the preferred habitat for most species, and under the best of conditions may have as many as 7,000 individuals per square meter! The lions share of leeches are sanguivorous, meaning they feed as blood sucking parasites. A small portion of leeches are predators and feed on small invertebrates and snails, some may even feed on other leeches, even their own kind. Leeches are part of the same group of animals as earthworms, and just like their worm cousins are heavily muscled with flexible segmented bodies. They range in size from less than an inch to nearly twenty inches and may grow as much as five times their normal body size after feeding. They are VERY stretchy! Many species have suckers located at each end of their bodies; these suckers allow them to move much like an inchworm moves. You may find them inching along under the surface film of the water hanging onto the sticky top layer of water molecules with both rear and front suckers. They are undulating and graceful swimmers preferring slow-moving, warm watery habitats. They will also move in this inchworm-like way on the bottom of ponds or other watery environments they are found.  Ephemeral ponds frequently dry up during extremely hot weather or during seasonal droughts. When this happens, the leeches will burrow into the mud, waiting for rainy weather and optimal conditions to return. They may survive a year or more without a blood meal!

For more than 3,500 years, leeches have been used for medicinal purposes. As far back as Pliny the Elder leeches were used as a means for bloodletting. Early physicians called leeches, a word derived from the old English word “leace” and translates to mean doctor or physician. These early physicians believed the body was made up of four “humours” that included blood, phlegm, black bile, and yellow bile, By applying leeches to slowly remove tainted blood from their patient, doctors of ancient times used them to cure patients of many medical complaints that ranged from gout to sore throats. It has long been believed that George Washington died from overzealous bloodletting by the presidential physician. Complaining of a chronic sore throat, Washington was bled four times in two days, relieving our first president of valuable blood supply and ultimately claiming his life.

Napolean Bonaparte imported six million leeches to treat his soldiers of various ailments. Most likely to help treat amputations and necrotic wounds. It has long been known that leeches can improve blood circulations which greatly increases the chance you will recover from a serious wound with no serious infections.

By the mid-1800s demand for leeches was so great that the French imported four million leeches a year for medical purposes. Eventually England jumped on the leech bandwagon and began importing as many as six million leeches a year from France. This was a lucrative field of work; in which individuals would collect leeches from any and all available water sources. This over collection greatly reduced their populations. Today medicinal leeches are bred and raised in sterile conditions that is referred to as hirudiculture. No fear of wild caught leeches being used to treat what ails you. Today leeches are used to help heal wounds after reattachment surgery, to help with healing tissue after plastic surgeries, as well arthritis and circulatory related health issues which is but a few beneficial aspects of their natural feeding habits.

Because leeches are more frequently parasitic than predatory by nature, the host, or prey they feed on get to live another day. Typically, they will feed on the blood of frogs, and other amphibians. Some individuals say if you want to remove the leeches from your pond, remove the frogs. I personally would not be a proponent of that strategy, as removing frogs from an established habitat creates another set of problems that can and does greatly affect the food chain in your pond. Some leeches are specialist though and feed only on fish, or perhaps turtles, others are generalists and don’t seem to care where their next blood meal is coming from. Using chemical receptors on their head provides a sense of smell and those that possess primitive eyes called ocelli can detect chemicals, light, heat, pressure, touch, and disturbances in the water. I am sure it was these opportunistic bloodsuckers that set their sights on my legs that day. My wading in the shoreline would most definitely be a disturbance in the water no respectable leech is going to pass up.

Most leeches release an anticoagulant and a form of painkiller to attach themselves without notice and allow for blood to flow freely for easier feeding. It may take a few minutes or up to an hour or more for the leech to feel satiated and release their host. If you find yourself in a predicament like I did, gently remove the leech using your fingernail to release the suction of the leeches mouth. Pulling on it may leave mouth parts behind causing severe itching. Do not use chemicals to remove the leech, while vinegar, turpentine, and alcohol will make it let go, it will also cause the leech to vomit in the wound potentially creating the perfect conditions for an infection to establish itself. Generally, bites are not painful (although there are exceptions), and do  not cause any lasting effects, but on the rare occasion that a person finds themselves allergic to the enzymes in the leeches saliva, a bite can be serious enough to require medical attention. Serious reactions would include red blotches, an itchy rash, swelling around the lips or eyes, feeling dizzy or faint and difficulty breathing indicating an anaphylactic reaction. In even rarer cases bacteria, viruses, and protozoan parasites from previous blood sources can survive within the leech for months and may potentially act as a vector and pass those pathogens onto the next host. However, this has only been confirmed on a few occasions.

If you are not completely grossed out and disturbed by the very idea of leeches, you can keep them as a pet that is sure to render some interesting conversations by visiting guests. Just feed them some snails or raw hamburger and your pet may stay around for more than ten years. Like many animals living in nature, they possess benefits to humans or other living creatures. In the case of the leech, it has helped in many medicinal ways for more than three thousand years, they provide food for fish, as well as a variety of other predators, including other leeches. If you find yourself the unexpected host of a bloodsucking leech…. remain calm and like all dedicated nature lovers say to yourself “how interesting,” then you have permission to freak out.

Monday, May 13, 2024

Carolina Leafroller Cricket

Several years ago, flashlight in hand, I was exploring my yard at night looking for insects to capture or photograph. A whole new variety of insects is active at night versus the daylight hours. The only way to find them is to stay up late and hope a beam of light flashes across a shiny body among the leaves. On this particular night, I found a small, but odd-looking cricket-like insect I had not encountered before. I captured several pictures of this new-to-me bug before it lost interest in my presence and walked rapidly away. The walk was more like a fast, awkward, hop-like sprint.

After searching the internet and field guides, I identified it as a Carolina Leaf-Roller Cricket (Camptonotus carolinensis). They are small crickets reaching barely ¾ of an inch, with antennae at least five times longer than their body. They are honey-like golden brown, which helps camouflage them against the foliage and leaves they live on. Some researchers claim they can hop, while others say they walk or run. The one I encountered did not try to hop. So maybe some species within this family of crickets can hop, while others cannot. While they are not uncommon in their range throughout Eastern North America, they are rarely encountered.

This is mostly due to their nocturnal nature, as they are active when most of us are sleeping. During the daylight hours, they produce a silk-like substance, comparable to the silk that silk moths produce, from glands located in their mouth. They use their mandibles to tear the ends of leaves and fold them back and while sitting on the leaf they will pull the cut pieces over their body and stitch them closed with the silk they produce. They are even able to pull those extremely long antennae into the enclosure!  This creates a nice little home in the form of a rolled leaf that camouflages it against the trees and other greenery they live on. This habit of rolling leaves for hiding spots is what earned them their common name of leafroller.

There are over six hundred species of leaf roller crickets in the family Gryllacrididae, which are the raspy crickets. Over a third of them are found in Australia, and the one featured here is the only species in North America. Unlike most crickets, grasshoppers, and katydids, the raspy crickets do not sing to attract mates or advertise their location. Nearly all insects that make sound also have ears for hearing. This helps them locate the proper mate during the breeding season. The raspy crickets, however, lack ears. So, it is still unclear why they possess the ability to make any sound at all when they cannot hear the sound being made by a potential mate. When alarmed they make a raspy sound that is produced by rubbing their legs across their abdomen. They may also stomp their feet in a cricket-like tantrum warning others to just hop away as this breeding site is taken and the female residing there is his.

 

During courtship, they make a vibrating sound by drumming on the substrate. Both males and females may perform a drum duet to attract each other's attention. Females possess a long projection coming from the back end of the abdomen, this projection is called an ovipositor and is used to lay eggs. This protrusion is not used for stinging. Crickets cannot sting. They can, like most all crickets, bite, fortunately, they are not prone to do so.

The female CLRC will likely dig into the soil and use this special apparatus to lay eggs that will hatch the following year. When the young hatch they will begin feeding on small soft-bodied insects like aphids or tiny caterpillars. They may also feed on some vegetation if the mood strikes them. Both nymphs and adults are omnivores and eat a wide variety of available food. The nymphs can also roll shelters and like their adult counterparts, may reuse these shelters rather than create new ones. They will leave a pheromone-laden scent trail they can track with their antennae back to the shelter. This reuse of shelters helps conserve energy by avoiding building new nests each day.

A night walk among the gardens and vegetation in and around your yard may yield unique and odd insect life like the nearly silent hunter, the Carolina Leafroller. Grab a flashlight and coax your children to join you,  then head outside and explore. 

 


 

Sunday, April 28, 2024

Evergreen Bagworm

Spring is a time of awakening when the landscape is green again, flowers are blooming, birds are making their way back home and the bagworms are hatching. One of the banes of homeowners, landscapers, and arborists is the bagworm. Tree branches decorated with spindle-shaped ornaments are not exactly what we had in mind when we planted our trees. So, what is a bagworm exactly? To me, they are both irritating and fascinating.

In our region, the most common one you will encounter is the Evergreen Bagworm, but Worldwide there are over a thousand different species. They go by several common names including Common Basketworm, North American Bagworm, Bag Moths, and my personal favorite Cuddle Sacs. This reminds me of the term Cul-de-sac, which is French for “bottom of the sack.” What an apt nickname for this unique little insect.

Their lifecycle begins in spring when the eggs hatch within the bag and leave the security of their winter home. Many will remain on the host tree, while others spin a thin thread of silk and wait for the wind to carry them to a new host tree or plant nearby. This phenomenon is called ballooning or parachuting and there is another animal that also uses this mode of transportation, spiders. Do you remember the end of Charlotte's Web when all of Charlotte’s babies, except one, ballooned away to new homes leaving Wilbur behind? Is there a quicker way to arrive at a destination than flying?

After arriving at their new host plant, the tiny larvae will spin a silken cocoon around itself and begin decorating it with bits and baubles found on the host. This sack will effectively camouflage the tiny larvae inside protecting it from predation. Now their only job is to eat and grow. The larvae stick their head and thorax out of the bag to munch on leaves and can retreat quickly if danger is nearby.

If you watch a bagworm closely you can see it move as the larvae wiggle around inside. They can move about freely carrying their sack with them, an insect version of a mobile home. Often we do not know we have a bunch of bagworms using our evergreens (or other trees) as their all-you-can-eat buffet until mid to late summer when the bags have grown exponentially and are now visible. They almost seem to appear overnight! The sacks have somewhat pointed ends, one end is for feeding, one end is for pooping. By August or September, they are ready to attach themselves permanently to their host tree and will use surprisingly strong silk to do so. If you have ever tried to remove a bagworm from a tree branch you can attest to just how strong this silk is, as it takes some effort to pull it free.

Everyone loves a love story, in the days of legends and myths there was a beautiful princess by the name of “Psyche”, and she fell in love with the son of Venus who as most of us knows was “Cupid”. Venus did not approve of this love relationship between her son and his beloved Psyche. Venus made life miserable for the poor princess. After some time, Venus felt guilty for her ill treatment of Psyche, and it was within her power to grant a great gift upon her, this gift was“immortality” Many moths are in the family of Psychidae and are called Psyche moths, which is a perfect name for moths believed to be the spirit of the lovely Princess Psyche.


At this point, they will pupate inside their bags and appear a few weeks later as adults. This is where things get really interesting. Males leave the sack and seek females who are still securely sequestered in their bags. Females cannot fly, they lack wings altogether. Therefore, the male must go to them. Some females will leave the bag and mating will occur after which she returns to the safety of the bag.  Although many more remain in the bag where mating takes place in what I can only imagine is a very awkward moment. The male then flies off in what I would describe as love them and leave them sort of way. Mother Nature, however, has a plan for our tiny Don Juan, he is destined to die shortly after mating. The female still stuck in her bag, having never seen the world like her lousy boyfriend, will lay up to a thousand eggs, and then she too will perish. The eggs overwinter in the bag and the cycle starts over again in the spring. Some females do not lay eggs, instead the larvae emerge directly from her body come spring. No one said life was fair. If all of this isn’t strange enough, in some species the females will lay eggs that are fertile without male fertilization in a phenomenon known as parthenogenesis. Saves the female those awkward love them and leave them moments.

Male Evergreen Bagworm---photo by K. Leeker

The most common bagworm in our region is the Evergreen Bagworm, and they are often found on juniper, cedar, and pine, although other hosts will be used as well such as sycamore, box elder, maple, and locust. For the past several years they have been on my St. John’s Wort plant.

For most of us having bagworms on our trees is just unacceptable and unsightly. I can certainly understand that feeling. Fortunately, the vast majority of the time they cause no lasting harm, in those cases your tree just may not be as aesthetically pleasing to look at. There are a few populations, however, that can be a serious problem. In those situations, when a severe outbreak is occurring, control will need to be used. If the problem is within the normal range handpicking the sacks off will be effective, although time-consuming. In the case of a severe infestation, you will need to use chemical sprays that contain Bt. Be sure to implement your control measures at the right time of the year for the most effective result. Whether handpicking or spraying they need to be removed in early to mid-winter. This is when the eggs are secured in the bag, therefore you can kill them before the eggs hatch. If handpicking, do not drop them to the ground, they will still hatch and find another host plant nearby. The bags must be destroyed to effectively control them

Besides ballooning, these tiny moths can spread by other means. Remember me saying that some females do not lay eggs, but rather the eggs remain inside the mother and the larvae emerge later from her body? Birds find them a tasty treat, and they will seek out these egg-laden females for food. The eggs have a very hard shell for an insect and often pass through the digestive system of the bird and remain unharmed, effectively spreading them far and wide, only to hatch and create a new generation. Not only do birds find them tasty and a great source of protein so do some people around the world. In primitive villages, the bagworms are encouraged to grow and then later harvested for a protein-rich snack.

If you decide the little spindle-like ornaments hanging from your trees are just not fitting in with your design vision, I recommend hand-picking as a means of an environmentally safe control option. If, however, your infestation is too severe chemical measures will need to be taken, just remember to follow directions exactly as given. While we are all busy cursing and controlling the dreaded bagworm, maybe we can take a few minutes to appreciate the uniqueness of the cuddle sack and its lifecycle.