Northern Mole Cricket

Few insects in nature are as rarely seen or as odd in appearance as the mole cricket. Looking superficially like its mammal namesake, the mole cricket possesses paddle-like forelimbs well adapted for digging and burrowing. Their head and thorax are heavily armored (for a cricket) and much wider than the rest of their body which is much softer in comparison. This abnormally large head is useful when barging your way through soil creating tunnels all night which they can do at surprisingly rapid speeds.  A torpedo-shaped body covered in fine hairs allows them to move rapidly both forward and backward through the tunnels they excavate. Their back legs somewhat resemble the legs of true crickets, but rather than being adapted for leaping (which they do poorly), they are used for pushing their way through soil. Northern Mole Crickets (pictured) are found throughout the eastern United States and parts of Canada. Their preferred habitat is the muddy or sandy soils along ponds and creeks. They also occur with some regularity in agricultural fields.

Males, like all crickets sing to attract mates, in the case of the mole cricket they dig a funnel-shaped tunnel that leads to the surface. Many species of mole crickets leave the tunnel open to the surface, but the Northern Mole Cricket places a dirt covering over his tunnel. Most likely this is to evade predators located at the surface. This danger to the male usually comes in the form of parasitic wasps, however other insect-eating predators like mice, toads, and wolf spiders all find mole crickets a tasty meal. The call of mole cricket is extremely loud and may attract females from as far as five miles away. Even with the dirt cover over his tunnel the male Northern Mole Cricket makes himself heard and his song vibrates the ground up to eight inches in diameter. For an insect barely an inch and a half long, this is an impressive feat. Both males and females possess shortened wings and are capable of flight, but females are more prone to fly than males. About half of females have functional wings, whereas the other half do not. Once a female homes in on a male's enticing song, those that can fly will take flight to his location. The unfortunate females lacking usable wings must travel over the surface of the ground in a daring journey with many obstacles and dangers in the form of predators. If a female is lucky enough to be underground nearby, she may travel by digging a tunnel that leads her directly to the male. Once mated the female will lay a large cluster of eggs in a chamber located off one of the main burrows. She will enclose the chamber with soil and remain with the eggs and guard them from predators for a short period before dying. The male dies shortly after mating.  Once the eggs hatch the young nymphs will feed on the root systems of various grasses and other plants.  In temperate climates, like Missouri, they will overwinter as nymphs or in some cases adults.

In their native lands mole crickets rarely cause harm to plants with their feeding because of the various predators that have evolved along with them to keep them in check. However, species that find themselves in new lands can wreak havoc on turf and pasture grasses. As they tunnel through the top few inches of soil they push the ground up creating ridges that increase the evaporation of surface moisture which disrupts the germination of seedlings and may damage the root systems of young seedlings. They will also feed, often unchecked on the roots of turf and pasture grasses. This constant burrowing and feeding can dry out the roots causing large patches of dead grasses. Fortunately, these invaders have not made their way into Missouri as of yet. However, they are found in many southern states where they do cause significant damage annually. Controlling mole crickets is not as easy as controlling other fossorial insects like grubs. It requires extensive management of the grasses and turf in question. First, it must be determined if the problem is mole crickets or some other culprit. If it turns out to be mole crickets, you will most likely need to speak to a turf grass expert to determine the best course of action to take.

Mole crickets are harmless to humans, but if you should decide to handle one be prepared that it may secrete a foul-smelling brown liquid from the posterior region that is sure to make you release it. If not, you may get a nip for holding on too long. The bite will be superficial but will definitely get your attention and make you think twice before handling one again. However, you will rarely see a mole cricket as these unique and odd insects are only active at night and live nearly their entire life underground. Occasionally they may come to the surface and a chance encounter will happen. Like those in Zambia, Africa, where mole crickets are considered good luck we too should consider ourselves lucky for the experience.

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.

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.