American Bumblebee

Growing up in Northwest Missouri, I distinctly remember insects being everywhere. Butterflies, bees, fireflies and many others were all plentiful and easy to find. Today, this is not the case, as more and more species find themselves in very real danger of becoming endangered and ultimately extinct. It seems bees are suffering population declines more than any other species of insects. There are more than 4,000 species of bees across North America, with more than a quarter of the bumblebee species in some state of decline, and nearly half of the other bee species listed as imperiled, threatened or endangered. These are truly frightening statistics! 

The American Bumblebee, once a widespread species often encountered in open fields, grasslands and agricultural areas, is now classified as threatened, critically threatened or endangered in all its range, having experienced population declines as much as 90% since the year 2000. They are currently extirpated from eight Northern states; Maine, Idaho, New Hampshire, Oregon, Rhode Island, Vermont and Wyoming. They are still commonly encountered in part of their range, mostly in southern states from Florida to Texas and north to Colorado to include many of the Midwest states like Missouri. Even though this bee still buzzes freely over a wide swath of Missouri, that does not mean we should become lackadaisical about its presence, in short order it can disappear leaving a void where it once survived. As a species that was described before our nation gained its independence, it would be sad indeed to lose it. 

The name of American Bumblebee is a bit misleading, as they are not the most widespread of the native bumblebees, although its historic range did include much of the United States and Southern Canada. These are a large bumblebee, with the queen measuring more than an inch in length, workers and males easily an inch in length or more. Males and females are dimorphic, with females having black and yellow banded abdomens typical of many bumblebee species, whereas males have all yellow abdomens that may or may not have a small rusty patch located at the end. This time of year, the new queens and males are spotted pollinating a wide range of flowers, such as thistle, goldenrod, clover and vetch, often favoring the purple flowering plants over others. These queens will mate and spend the winter hidden away in leaf litter or in rotten logs. The males and other members of the hive will perish. In early spring, as temperatures begin to rise, queens will seek pollen and nectar from any available plants and begin setting up a new nest. These bees’ nest above ground in thick bunches of grass or hay bales. They will sometimes use old bird’s nests, or even nest underground, utilizing old rodent burrows. Man-made items have been known to be used as well, such as cinder blocks, buckets and abandoned sheds.

The new queen will care for the developing workers until they reach adulthood. At this point she will remain home and continue to lay eggs while the workers keep the nest clean and care for their queen and her offspring. By summer’s end the nest may contain as many as two hundred workers. Occasionally female workers may produce their own eggs, which will develop without fertilization by a male, and will produce offspring destined to be males. The queen is often not tolerant of this behavior and will kill these workers. Maybe to reduce competition. Once the hive reaches sufficient size, the queen will shut off the hormones she utilizes to keep her female workers infertile and will begin laying eggs destined to be males and new queens. Squabbling among the workers and the queen is common, and by the end of summer the workers will attack their queen, stinging her repeatedly until she perishes. When the first cold weather of fall sets in, the infertile workers and males will all die, leaving only the newly bred queens that will overwinter and repeat the cycle all over again the following spring.

Like most wild creatures, they have predators who often prey upon them. Mammals like skunks, raccoons, and bears all prey on bumblebees and their food stores including pollen, nectar and larvae. Crab spiders, robber flies, and ambush bugs all feast on bees, and often hide among flowers to deceptively attack them as they forage for pollen and nectar. Sneakier still are the parasitoids, like many species of flies that attach themselves to the bumblebee in flight and lay an egg within the bee. The egg hatches inside the bee and feeds on the bee’s tissue from within. The bee will live almost two weeks under the onslaught of the feeding fly larvae. The fly then pupates and resides inside the bee throughout the winter as a fully developed adult. When spring returns, the fly emerges from the dead bee and seeks another bee to continue its lifecycle. There is also a nematode worm that parasitizes American Bumblebees. This parasite does not kill or even reduce its lifespan, but it does render the bee sterile.

Even though as much as 30% of bumblebees are parasitized by some sort of parasite, this is not the greatest threat these bees face. Humans and our activities are.  As open spaces are replaced by urban expansion and agricultural growth, the American Bumblebee finds itself struggling to survive.

 

Spittlebugs

 

Spittlebugs are the nymphs of froghoppers, and there seems to be some debate as to whether that is because they can jump 100x their body length! Or if the name came to be because their head superficially resembles a frog head. They are a common sight all over Missouri, the spit balls they leave behind are easily spotted and for those that have no idea what they are they can be a bit perplexing. Inside that foamy spit-like substance is the nymph of the froghopper. It is this foamy matter that earned them their common name. the foamy spittle goes by various names including frog spit, cuckoo spit, and snake spit.

Many insects feed on the sap of plants or trees, usually these insect are seeking the rich, nutrient packed sap. In the case of the spittlebug, it does something remarkable. It feeds on the nutrient poor diluted sap, made up mostly of water. This thinner water-sap is headed to the roots, and spittlebugs intercept it for a meal. They produce symbiotic bacteria, that allows them to receive the nutrients, such as important amino acids. This watery diet would most like kill any other bug for lack of important nutrients. Because of this watery diet they also produce copious amount of urine,  as much 280x their body worth of urine! This would be like a human voiding 2700 gallons of urine each day! Because the spittle evaporates faster than water, it explains why they must produce so much of it each day.

The foam is produced using the excreted urine emitted from their backside, that combines with a sticky substance that helps adhere it to plants. The foam not only hides them from potential predators and parasites, which is said to taste acrid and distasteful to would-be predators. Not that I would want to taste it and see if they are right!  The foam also protects them from weather fluctuations, by insulating them from cold and heat. This thermal control as well as the moisture control, keeps the insect from drying out, which would a certain death sentence. They are capable of producing a yellow blood-like substance from their legs, that it thought to taste bad to predators.

 

In scientific studies done in Berlin, Germany scientists were trying to understand the prey response to the foam. Using ants as their predator of choice, they discovered that when the foam was placed in a dish the ant would sip from it as if gleaning moisture from it. But when placed on the foam they struggle vigorously to free themselves, exhibiting the adhering capabilities of the foam. So how does the foam not cause the same problems for the nymph living inside? Apparently much like the spider navigates its own web without sticking to it, the spittlebug possess the same amazing ability. Breathing within the little foam shelter is done with the use of special breathing apparatuses on their abdomen. The foamy bubbles are filled with oxygen, and occasionally the nymph may pierce a bubble to extract oxygen.

Adults are capable of jumping as much as 28 inches vertically from plant to plant. This high jumpcapability would explain the name froghopper. This acrobatic feat is a more impressive performance relative to body size than the flea! In northwest Missouri the most common froghopper is the two-lined spittlebug. The adults are black with two reddish colored lines. Like the nymphs living in the spittle, the adults also feed on plant tissue. They usually don’t occur in large enough numbers to cause any significant damage to plants. Occasionally there may be population explosions, and during those outbreaks they can cause damage to turf grass and various plants. If their feeding is causing harm you may have to resort to insecticides for control.

A few weeks ago, my granddaughter and I were driving around the fields when she asked me what those white things were on the plants, and by white things she was referring to the foamy substance produced by the spittlebug. I told her that an insect lived inside,  but she looked rather dubiously at me, most likely thinking I am crazy. I opened one to show her, and she pronounced it cute. In a yellow-green, wet, alien-looking way I guess they are. Nature discoveries can be found in surprising places and there is no better way to explore than with a child. This shared exploration will take you back to your own childhood, and bring back the memories of the discoveries you made all those years ago.

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.