Rosinweed

Thanks to my wife's work with a conservation-minded gardening group, dozens of wildflower species adorn our Columbia, Missouri, yard; of these, rosinweed is certainly the tallest, topping out at almost seven feet.  A native of prairies east of the Rockies, this wildflower may look like a sunflower species but is actually a member of the aster family.

 

Since rosinweed spreads by both seed and root systems, it may form extensive stands under favorable conditions.  And while it attracts a wide variety of pollinating insects, it is also a host plant for gall wasps, the larvae of which attack its tall, sturdy stem.  In some regions of the country, this wildflower has been domesticated for seed oil and livestock forage.

Of course, at our place, rosinweed is purely decorative though we welcome all pollinators that visit these towering plants. 

Their Time in the Sun

Over the past week, annual cicadas have been emerging in our neighborhood, their loud, ringing calls but a minor disturbance.  Indeed, compared with their periodic cousins, which emerge in massive swarms, the annual cicadas vary in their number and impact each year.

Having spent a few years gathering nourishment from tree roots beneath the soil, they emerge in late summer to molt, mate, lay their eggs on terminal tree branches and then die; they will not eat during their brief period above ground.  On the other hand, they themselves may be consumed by Mississippi kites, blue jays, raccoons, feral cats and other wildlife. 

Once the larvae hatch from the eggs, they drop to the ground, burrow into the soil and attach themself to a rootlet; thus the cycle continues.  How can we complain about their noisy mating calls knowing that they enjoy such a brief time in the sun? 

A Feast on the Driveway

For the last few days, a mix of songbirds have been gathering beneath our large Siberian elms, feasting on nearly invisible prey that they pick from the driveway.  Based on past experience, I know the victims are the tiny, translucent larvae of elm-leaf beetles.

Robins, spotted towhees, house finches and chipping sparrows have been the primary diners and it is amazing how quickly they locate and ingest the larvae.  Of course, those slugs that fall into the grass are relatively safe; no comparable flock of hunters has been observed on that side of the tree.

Another brood of larvae will hatch and drop in late summer when a second feast will ensue.

See also: A Shower of Larvae 

Common Green Darners

Yesterday afternoon, a common green darner was zooming about our front yard.  Easily identified by its large size and thick, green thorax, this dragonfly is common throughout most of North America and is known for its seasonal migrations, often in large swarms.  On the other hand, some green darners do not migrate at all, wintering as aquatic larvae in ponds.

Autumn migrations, generally to Florida or Mexico, begin by September and spring migrants usually appear by April, often arriving before non-migrant darners emerge from the water.  Of course, as with monarch butterflies and other migrant insects, those returning from the subtropics are the offspring of those that migrated southward in the fall.

Both the adult darners and their aquatic nymphs play an important role in controlling mosquito populations.  For that and for their aerial displays, we humans are grateful. 

Hovering Grasshoppers

Sitting in the shade on another hot, sunny day along the Front Range, I watched a small group of grasshoppers, hovering above our burned-out "lawn."  Though I have often seen them making brief flights between feeding areas, I don't recall having observed such prolonged hovering.

Indeed, to my human eye, they resembled a patrol of military choppers, searching for enemies in the grassy tangles below.  In fact, they were likely male grasshoppers, trying to impress females on the ground.  This mating behavior, apparently common, has managed to escape my attention over the years.

Just the latest example of my limited knowledge of the complexity and diversity of nature, despite many years in the field.  We should all acknowledge our incomplete understanding of the natural world and protect as much as possible while it still exists. We depend on her varied ecosystems far more than we are willing to admit. 

From Cicadas to Fireflies

Now that the swarms of periodic cicadas are dying off, fireflies have emerged to grace our evenings and, of course, to entertain children.  Soft-bodied beetles, fireflies are represented by more than 2000 species across the globe; their range includes Temperate, Subtropical and Tropical regions where they prefer relatively moist environments.

Due to the large variety of fireflies, it is difficult to generalize about their life cycle, which may span a couple of months or several years.  In most species, eggs are laid on or within the soil; these hatch to release larvae which feed on a variety of invertebrates.  Bioluminescence is present in most larvae species and is thought to warn predators that they are distasteful, poisonous or both.

Most species of firefly overwinter as larvae and then pupate. Adults emerge in late spring or summer and it is then that we notice them, twinkling in the darkness.  Bioluminescence in adults is used both to attract mates and to scare off predators though the females of some species use it to attract males on which they feed; the adults of some species do not feed at all while other species feed on small insects or vegetation.  Whatever their habits, they are certainly a more agreeable bunch than the cicadas.  

Sex & Procreation

Last evening, I watched thousands of periodic cicadas swarm our large deciduous trees.  Blue jays and starlings turned up to munch on a few while flocks of chimney swifts devoured those that strayed above the treetops.  

Gathering to mate, the cicadas' behavior is purely instinctual; like almost all animals, they do not understand its purpose.  They have no concept of parents and will never see their children.  Yet, their behavior is an important cog in nature's cycle of life.

We humans, endowed with a large brain, have long understood the relationship between sex and procreation.  We have also come to recognize the importance of sexual activity beyond its role in perpetuating our species.  Unfortunately, certain segments of human society (religious and political) want us to function like cicadas; in their minds, sex is purely a procreative act and any behavior that disrupts this association is sinful, illegal or both. 

Feasting on Cicadas

This morning, a flock of six Mississippi kites skimmed the treetops in our neighborhood, feasting on the countless cicadas.  Such a windfall of nutrition does not go wasted in nature.

The periodic cicadas seem to be reaching their peak emergence, landing on anything or anyone that they encounter.  As I worked in the yard today, I regularly brushed them from my cap or shoulders and they (or their exoskeleton) adorned almost every plant on our property.

As for the kites, which seem to be increasingly common summer residents in Central Missouri, the slow-moving cicadas are easy targets.  After filling their bellies, they ascended to higher altitudes, soaring above the city and letting other, less agile birds attack the hapless insects.

Cicada Armageddon

This spring, periodic cicada brood XIII, in the Midwest, and periodic cicada brood XIX, across the Southeast, will emerge together for the first time in 200 years.  Unlike annual cicadas, which are noisy but are otherwise shrugged off as a minor nuisance, periodic cicada broods can be deafening and pose some significant problems.

While they do not bite and are not poisonous, they can cause vegetation damage.  Domestic pets can develop intestinal obstruction if they consume too many of these tasty insects and humans can be injured if they slip on the decaying carcasses.  But the cicadas offer a windfall of nutrition for many birds and mammals and, in death, return nutrients to the soil and plants.

Brood XIII, 17-year cicadas, hatched in 2007, while brood XIX are 13-year cicadas that hatched in 2011.  The hatchlings drop from the trees in which their eggs were laid and burrow into the soil; finding a rootlet, they spend almost all of their life in the dark, drawing nutrition from that appendage.  When the larvae finally emerge, they crawl up a tree trunk and molt to their adult stage; adults, which do not feed, live only long enough to attract mates (hence the noise), mate and lay eggs. 

 

Summer Switch

By mid summer, many birders lose their enthusiasm for birdwatching jaunts (at least at their local hotspots).  The migrants are gone and the well-known summer residents have settled into the business of raising their young.  Heat often dampens one's interest in hiking and many of the country roads have turned to dust.

Of course, most birders are naturalists at heart and take an interest in other life forms as well.  Summer is a great time to explore the insect population, an activity easily combined with "wildflower watching."  Indeed, these colorful and interesting plants attract a wide variety of pollinators and this interaction is vital to the health of natural ecosystems.  On this sunny afternoon, our stand of purple coneflowers (photo) was alive with dozens of bees, butterflies and other insects.

Shorebirds will begin to drift southward in a week or two and late summer vagrants will add a bit of spice to birding trips.  In the meantime, I recommend learning more about some of our planet's smaller and more colorful species. 

 

A Mourning Cloak in Winter

Yesterday afternoon, while hiking atop a ridge south of Columbia, my wife and I enjoyed both the mild, sunny weather and broad vistas through the leafless forest.  But the highlight of our walk was the sighting of a mourning cloak butterfly.

Common throughout Missouri, mourning cloaks winter as adults, sheltering in tree cavities or beneath loose bark; on warm, sunny winter days, they often emerge to scour the woodland.  These Northern Hemisphere butterflies may live up to 12 months but produce only two generations each year.  Eggs are laid on the terminal twigs of host trees (elms, poplars, hackberry, willows) and the caterpillars (which undergo several molts) feed on the leaves of those trees.  Adult mourning cloaks feast primarily on tree sap though they may sip nectar from woodland flowers as well.

In all my years of wandering through winter forests, this may be the first time I have encountered a butterfly in February.  Just the latest reminder that nature's diversity is under appreciated, even by those of us who spend a great deal of time tramping through her landscapes.    

Starlings Take Over

Now that most of the swallows, swifts and nighthawks have departed for the south, European starlings are swooping across the mid-day sky, snaring insects that continue to thrive in the mild autumn weather.  Though despised for a variety of reasons, these immigrants do play an important role when it comes to insect control.

Furthermore, starlings are agile fliers, as demonstrated by their aerial ballets over farm country.  Watching them maneuver above our property, they are certainly as capable of feasting on flyings insects as the summer insectivores mentioned above.

Nature's complex web of life is flexible.  When one predator moves on or succumbs to human activity, another takes its place, whether native or non-native.

Palm Lines

This afternoon, while sitting on our back deck, I read a short story by Max Beerbohm titled A. V. Laider.  Set in the early 20th Century, it relates the discussions of two English gentlemen who meet at a seaside resort while recovering from influenza.  Their initial discourse is spawned by an article in a London journal titled Faith and Reason.

This leads to a debate about palmistry and they both claim to accept its legitimacy.  The remainder of the story is devoted to the guilt that has haunted A.V. Laider after he failed to warn friends about what he saw in their palm lines, leading to unnecessary tragedy.  The reader is left to decide if his account was truthful or simply a debate ploy.

When I finished the short story, I gazed at my own palm with its varied lines and wrinkles.  As I did, a ladybird beetle landed on that open hand and wandered about its surface, seemingly inspecting its crevices and their significance.  Before flying off, the beetle left a short, dark line of its own, a powdery residue from its latest meal.  Apparently, she and I agree on the subject of palmistry (and on Faith and Reason for that matter).

Lesser Meadow Katydid

Most grasshoppers are not overly appealing (except of course to the birds, reptiles and mammals that feast on them).  Indeed, hordes of grasshoppers can destroy crops or gardens and may even produce a slippery mess when they turn up in cities (see Grasshoppers invade Las Vegas).  Then there is their habit of spitting "tobacco" in your hand, a fact that I learned as an adventurous kid.

But this afternoon, while sitting on the porch, I encountered a tiny grasshopper with extremely long antennae.  It was a lesser meadow katydid, identified by its size (less than a half inch long), its bright green color with a rusty spine stripe, its very long antennae and its long, thin legs; females have a pointed abdomen that serves as an ovipositor.  Like other grasshoppers, it feeds on a wide variety of grasses and other plants but it's too damn cute not to like; besides, it's also known to consume the eggs of some "harmful" insects.

Meadow katydids are found across the globe, preferring warm, humid grasslands.  Apparently, our front lawn qualifies in that regard. 

Cloudless Sulfur Butterflies

Over the past week, I have noticed a large number of moderate-sized, yellow butterflies in our Columbia yard, moving rapidly through the property.  These are cloudless sulphur butterflies, common throughout the eastern half of the U.S.

The adults feed on a wide variety of flowering plants but females lay a single, pill-like egg on the leaves of cassias, a group of legumes.  The egg hatches to yield a bright green or olive-colored caterpillar that harbors longitudinal stripes.  After feasting on the host plant, the caterpillar spins its chrysalis which resembles a folded, dying leaf; of course, an adult eventually emerges from this camouflaged chamber.

Closely related to cabbage whites, cloudless sulphur butterflies produce several generations in the course of a summer and then drift southward as autumn approaches; the majority winter in South Florida or South Texas.  The increased numbers that I observed this week likely represent the vanguard of that migration. 

Tiny Dragonflies

Last evening, as the sun was setting, I stepped out into the sultry air to survey the yard.  There I encountered a swarm of insects, zooming above the lawn and flowerbeds.  Their size initially suggested that they were bees but, once immersed in the swarm, I realized that they were very small dragonflies.

None alighted on vegetation to permit close examination and the dragonflies did not possess any distinct or colorful markings that characterize larger, more familiar species.  I concluded that they were likely eastern amberwings, attracted to the yard by unseen gnats or mosquitos.

Their uncertain identity did not detract from the spectacle and I watched their energetic attack until the heat and humidity encouraged my own retreat.  Of course,  I appreciated both the show and their service; natural insect control is far preferable to the use of toxic chemicals.

An Aerial Feeding Frenzy

Last evening, while reading on the front porch, I caught sight of a large swarm of gnats, hovering above our lawn and illuminated by the setting sun.  Of more interest were squadrons of dragonflies, streaking through the insect cloud from all directions.

Though not nearly as dramatic, the event reminded me of  a scene from marine nature documentaries in which large schools of fish are attacked by gannets, sea lions and dolphins.  In reality, our modest suburban feeding frenzy was just as important in nature's complex web of life; both spectacles nourish predators, promote natural diversity and keep prey populations in check.

Unfortunately, most suburbanites are uninterested in the insects that inhabit or patrol their yard.  It is only when those "pests" attack their gardens or invade their homes that they take notice and call their friendly exterminator. 

Cicada Debut

The first chorus of annual (Dog-Day) cicadas rang through the neighborhood late this morning.  Common throughout much of the country, especially east of the Great Plains, these insects, unlike periodic cicadas, do not appear in overwhelming numbers.

Nevertheless, annual cicadas do make their presence known and their loud calls increase through the summer.  Having spent a few years underground, nourished by the fluids in a tree root, they emerge only to breed; indeed, adults do not eat during their brief lives though they do provide food for jays, raccoons, opossums and house cats, among other scavengers.  Eggs are laid in grooves that the female carves on terminal tree branches; once they hatch, the larvae drop to the ground, burrow into the soil and begin their years underground.

While cicada choruses can become annoying by late summer, their initial, tentative calls are welcome, assuring suburbanites that nature's cycle remains intact despite our careless stewardship of the planet. 

A Skink in the Compost Bin

When taking watermelon rinds out to the compost bin last evening, I opened the lid to find a five-lined skink (also known as a blue-tailed skink) scurrying across the vegetative debris.  A dedicated insectivore, he was surely taking advantage of the fact that numerous insects and spiders are drawn to the bin's rotting contents.

In a way, we are facilitating his hunting activity, just as bird feeding concentrates prey for a number of falcons, hawks and other predators.  Are we thereby creating an imbalance in our backyard ecosystem or does the value of a compost bin outweigh the impact on our resident invertebrates?  Should I screen in the compost to keep out predators?

This argument is partly in jest but also reminds us that most human activity, however well-intentioned, has an impact on natural ecosystems.  Our species broke from those ecosystems once we developed the means to avoid being prey ourselves.  For now, with all due respect to the spiders and insects, I will not evict the skink from our compost bin.

White Clover

White clover (often called Dutch clover) is a Eurasian species that has become widely naturalized in North America.  Our clover "crop" seems especially abundant this year, in part due to the fact that we do not use herbicides or pesticides on our lawn.

A perennial, white clover forms extensive root systems which may remain viable for 100 years or more.  Beyond its role in adorning lawns (and providing material for clover chains), this wildflower attracts a wide variety of bees and butterflies and is consumed by most mammalian herbivores (especially cottontails).  Humans also partake of the stems, leaves and flowers, using them in salads and soups or as garnishes for a variety of foods.

Sitting on our front porch this afternoon, I watched honeybees as they foraged across the floral carpet.  Unlike some suburbanites, we are pleased to have a healthy clover crop.