A Stick isn’t Always a Stick!

This northern walkingstick (Diapheromera femorata) is close to 4 inches long and is most likely a young insect or nymph, which are light green.

The northern or common walkingstick insect is a master of mimicry. Slender, green or brown, nocturnal and timid, it looks like a twig or branchlet. I’ve only spotted a few at our cabin in Central Minnesota over several years’ time. They were brown — except for this one, which was pearly green and sitting on the side of our cabin.

Since they are wingless, slow-moving and don’t bite, northern walkingsticks need some way to elude their predators — mainly songbirds and parasitic insects. They are extraordinary mimics and blend in perfectly with tree branchlets and twigs. Unless you spot them crawling, or they roost on a building or another object, it’s very difficult to see them. Males are brown and about three inches long. Females are greenish brown and closer to four inches in length.

So what do walkingsticks do? They are primarily nocturnal and rest during the day extending their front legs forward next to their antennae, which makes them appear more sticklike. At night they eat! The larval stages eat leaves of shrubs that are close to the ground, especially hazel, rose, blueberry and serviceberry. Adults feed in the tops of trees and appear to favor oaks, basswood, black locust and black cherry. When eating, they often sway like the leaves and branches around them, which provides greater camophlage.

Walkingsticks fold their front legs straight forward, next to their antennae, to appear more sticklike.

Northern walkingsticks mate in the afternoon and evening from late summer to mid-autumn. The female lays her eggs from high up in the trees. The eggs just drop to the ground to overwinter in the leaves. In the south, the eggs hatch the following spring. In the northern states and provinces, there’s a two-year cycle in which the eggs don’t hatch until the second spring. So, in Minnesota, the odd-numbered years produce many young and the even-numbered years produce fewer insects. The newly hatched larvae, or nymphs, climb up into shrubs where they molt several times before reaching adulthood. They are miniatures of their parents, but are green like new spring leaves.

We have just one species of walkingstick in Minnesota — it lives in the eastern United States and the southern portions of adjacent Canadian provinces. Most of the world’s 3000 stick insects live in the tropics.

Further reading: 

Northern Walkingstick: UW-Milwaukee Field Station

Walkingstick: Iowa State University Extension and Outreach

Northern Walkingstick: Minnesota Seasons

Ebony Jewelwing

What do you associate with the words “winged beauties”? Many would answer birds and butterflies — and I’d add damselflies and dragonflies, too. On a sunny, warm morning, a pair of inky black wings flutter near the Snake River. At first I think it’s a butterfly, but a closer look reveals the electric-blue-green body of a male ebony jewelwing damselfly; he flashes cool and iridescent in the morning sun.

Inky black wings and a blue-green abdomen identify this male ebony jewelwing (Calopteryx maculata).

A member of the broad-winged damselflies, ebony jewelwings fly more like a butterfly than like their dragonfly relatives. Their wings are 1-to-1½ inches long and their body length is up to 2¼ inches. The male’s colorful abdomen — green, teal, blue, even a hint of purple — shimmers in the sunlight. A female ebony jewelwing is similar in appearance, but not as showy as a male. Her body is brown with little bits of blue or green. Her wings are more transparent black and display a distinct white spot near each tip. (See a female at Wisconsin Odonata Survey.)

In the eastern United States and southeastern Canada, look for ebony jewelwings perched along shady banks of shallow streams and slow-moving rivers from late May until September. Adults live for about 20 days. A mating pair will often fly attached in the heart-shaped “wheel formation” and remain connected for several hours. Females deposit eggs inside of submerged water plant stems in quiet sections of streams or rivers. The larvae or naiads live in the water for about a year and eat other aquatic larvae, such as mosquitos and mayflies. Adults eat most soft-bodied insects, for example small moths, mosquitos, mayflies, gnats, flying ants and termites.

The Snake River in east-central Minnesota provides the habitat needed by ebony jewelwings.

Even though jewelwings are voracious predators, they serve as supper to other creatures — turtles, frogs, fish, bats and birds, such as red-winged blackbirds, blue jays, flycatchers, purple martins and kingfishers.

How does one distinguish between a damselfly and a dragonfly? A few simple differences make it easy to tell them apart. Generally, damsels hold their wings folded vertically above their body, while dragons spread them horizontally when resting. Damselfly abdomens are more slender than the stout dragonflies’. Damselfly eyes are set far apart on the sides of the head, but dragonfly eyes wrap around and touch on top of the head.

A green darner dragonfly (Anax junius) exhibits the horizontal wings, stout body and wrap-around eyes characteristic of dragonflies.

Vertically folded wings, a slender body and eyes set far apart on each side of the head are characteristic of the ebony jewelwing and other damselflies.

Damselflies and dragonflies belong to the order Odonata, which means “toothed ones.” Many come in beautiful, iridescent color combinations. Fossil records indicate that Protodonata, the ancient ancestors of both dragons and damsels, arose about 325 million years ago. The first Odonata fossils are dated at a little older than 250 million years, which means they’ve inhabited Earth’s skies since before dinosaurs existed. I love to watch and think about these ancient, graceful creatures that add so much beauty to our woods and gardens.

 

Late Summer Along Minnesota’s Snake River

Bottle gentians (Gentians andrewsii) signal the arrival of late summer in east central Minnesota.

Much as I hate to admit it, (since I’m a big fan of sun and warmth), the unmistakable signs of late summer color the banks of the Snake River in Pine County, MN.  After 36 summers and autumns along the river, I know them well.

A female long-horned bee (Melissodes, spp.) pollinates a tall sunflower (Helianthus giganteus).

The season’s first bottle gentians, ironweed, tall sunflowers, native field thistle, Joe-Pye and goldenrod add their showy flowers to black-eyed Susan’s, fleabane, monarda and coneflowers already in bloom. Riverbank grapes turn dusky blue, dogwood berries ripen to white on scarlet stems, wild rose hips, hawthorns and chokecherries hang plump and red.

It’s a productive year for the bur oaks. Acorns fall like small rocks that bounce and roll down the roof before they plunk onto the wooden decks. Chipmunks, squirrels and mice snatch up ripe hickory nuts and soon the hazelnuts will be ready. As hard as I’ve tried, I’ve never beaten the squirrels to the tasty hazelnuts.

Crickets and katydids sing in place of wood thrushes and robins. Thank goodness for cardinals that sing at dawn and dusk, and for the melodic cooing of mourning doves during the hot afternoons.

It’s all lovely, and I wouldn’t change it — perhaps stretch it out further into the year — but this late-summer beauty makes me wistful for abundant hours of sunlight, wide-open windows, warm breezes and a simple outfit of shorts and a T-shirt. Let’s hope for a long, mild autumn.

Our neighbor, Ed’s, puple coneflowers (Echinacea purpurea) attract many species of butterflies.

Native field thistles (Cirsium discolor) provide pollen and nectar to insects and nutritious seeds for birds and other creatures.

Green-headed coneflowers (Rudbeckia laciniata) provide pollen to bees later in the fall. A hover or flower fly (Toxomerus geminatus) rests on the bloom.

Bur or mossycup oaks (Quercus macrocarpa), a type of white oak, are named for the fringe that surrounds the top of the acorn cup. They are an important food source for many birds and animals.

Riverbank or frost grapes (Vitis riparia) are a native Minnesota grape that favors a moist environment and feeds many bird species.

Gray dogwood berries, or drupes (Cornus racemosa) are a favorite of thrushes, robins and other birds.

Black-eyed Susans (Rudbeckia hirta) mix with fleabane and field thistle in a colorful patch next to the road.

Garden Bugs: Nifty or Nasty?

Like most of life, my garden is a mix of good and not so great: desirable plants and weeds, loamy soil and heavy clay, beneficial insects and annoying pests — and early August brought many types of insects to our garden. Here are just a few stand-outs.

Japanese beetles (Popillia japonica), an invasive species, are a type of scarab beetle that destroy many plant species in North America.

The biggest pest in our yard is the Japanese beetle, which skeletonizes the flowers and leaves of many plants. A few weeks ago they favored apple and crabapple trees, but I’ve also pulled them off of my rose, asters, day lilies and purple coneflowers. Now, they are shredding my hosta and anise hyssop blossoms. According to the Minnesota Department of Natural Resources, the beetles are native to northern Japan and probably arrived in a shipment of iris bulbs in 1916. They have no natural predators, although some birds, such as starlings, robins, bluejays and sparrows will sometimes eat the adult beetles and the grubs, which live in lawns.

Yesterday I picked 46 beetles off of my royal standard hostas. I used to squish them, but that releases their pheromones, which attract more beetles. Now I pick them off by hand and drop them in a small pail of soapy water, which kills them quickly without releasing their pheromones. I don’t use an insecticide because so many beneficial insects would die from the chemicals.

The convergent lady beetle (Hippodamia convergens) is a North American native that feeds on aphids, whiteflies and other pests.

Not all ladybugs are red or orange. The tiny esteemed ladybug (Hyperaspis proba) is black with yellow spots.

Unlike the Japanese beetle, ladybugs, or ladybird beetles, especially those native to North America, are beneficial to gardens. More than 500 species of ladybugs have been identified in the United States. Mom taught us never to harm ladybugs because they eat aphids, a major garden pest. Our native ladybugs don’t bite, so if you feel a pinch and find it’s from a ladybug, it is likely to be an Asian ladybug, which do nip — mainly because they seek moisture and salt, or they feel threatened. Asian ladybugs were imported in the 1970s to help destroy predators in agricultural operations. I let them be when I find them because they destroy so many aphids and other pests. However, the native ladybugs are better suited to our gardens and plant species.

Aphids, that favorite food of ladybugs, are tiny, often wingless, and very plentiful. There are more than 300 species of aphids in Minnesota and they are found on all types of plants. Most aphids on a plant are females that reproduce asexually, without having to mate. They also give birth instead of laying eggs. The newborns are clones of their mother, so they, too, are female. (Environmental conditions sometimes cause females to produce both female and male offspring, which are genetically identical to the mother, except that males lack one sex chromosome.) They come in many different colors. I’ve seen green, black, red, and I have orange ones on some of my milkweed plants. When aphids suck a plant’s sap, it causes curling, yellowing and browning of the leaves. Aphids also secrete a sticky, sweet liquid called honeydew. Last summer, during a heavy infestation of aphids, my milkweed plants were dripping with honeydew and covered with ants, which are attracted to the sweet liquid. Even though I washed the milkweed with water from the garden hose daily, the plants were disfigured and messy.

Tiny soft-bodied aphids (Aphids nerii) suck plant juices from common milkweed. The white specks are moltings that are stuck in the honeydew.

 

This juvenile male eastern pondhawk (Erythemis simplicicollis) will attack any type of insect its own size or smaller, including others of the same species.

In contrast to the slow, rather clumsy flight of beetles, several species of dragonfly dart and swoop among the garden plants. Perched on a milkweed leaf, a green eastern pondhawk zips lightning-quick from its perch to capture a fly. Its powerful jaws quickly crush and consume its prey. Common in gardens, dragonflies eat mosquitoes, gnats, flies and other insects. Their shining colors add beauty to the garden.

Most meadowhawks (Sympetrum spp.) fly in late summer and autumn.

Monarchs, red admirals and other butterflies are frequent visitors to our garden — especially now when the milkweed is blooming and the plants are in their prime for feeding monarch larvae. These tiny caterpillars feed only on milkweed and I discovered two of them a week ago. Adult monarchs sail through the garden stopping to nectar on milkweed, Joe-Pye, garden phlox and purple coneflowers.

Monarch caterpillars hatch and grow only on milkweed plants.

Adult monarchs (Danaus plexippus) and many other butterfly species nectar on common milkweed (Asclepias syriaca).

A red admiral (Vanessa atalanta) nectars on garden phlox (Phlox paniculata).

Red admirals are smaller and fly faster and more erratically than monarchs. A male finds a sunny spot and watches for a female to fly by. After mating, the female lays eggs on nettle plants. Adults nectar on milkweed, red clover, ripe fruit and tree sap. They are one of the few species that overwinter in Minnesota, often in a wood pile or mound of leaves.

The summer garden harbors so many interesting, and often beautiful, insects. Next time you’re working in your garden, or simply enjoying your yard, take a look at the diversity of these tiny creatures all around us. The majority of them are either beneficial or harmless. Nifty or nasty? You decide!

Lake Michigan Walk

In August, many wildflowers begin to bloom in the Upper Midwest. Bees, wasps, moths and butterflies visit them for nectar and pollen. While in Milwaukee, Wisconsin, last weekend, we walked along Lake Michigan to enjoy the warm sun, gentle breeze and flowers both native and non-native that grace the shoreline. Among the blooms were chicory, Queen Anne’s lace, everlasting pea, goldenrod, sweet clover, gray-headed coneflower, bouncing Bet, red clover, Black-eyed Susan, monarda and lesser burdock. (If you look closely, you’ll spot a few pollinators, too.)

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Summer Solstice

The first wild rose (Rosa blanda) of early summer.

It is the season of light in the North. Earth bows its northern pole to the sun extending daylight to almost sixteen hours — eight more since winter solstice last December. Spring flowers are finished blooming, trees are fully covered in lush green leaves, and swelling buds on many perennials will open soon. Fireflies glow in the night. During the day, delicate lacewings, damselflies and dragonflies patrol the garden for pests. I spotted my first monarch of the season a couple of weeks ago when it visited our milkweed patch, which is almost ready to bloom.

Solstice was mild and clear with a high of 76℉. I enjoyed the company of good friends for lunch at an outdoor restaurant. Later, I sat in our garden to soak up the late-afternoon sun’s warmth, to listen to the robins sing and to toast the long summer ahead.

A monarch (Danaus plexippus) seeks nectar among the buds of swamp milkweed (Asclepias incarnata).

Lacewings (Chrysoperla carnea) eat aphids, mites and other garden pests.

An eastern forktail (Ischnura verticalis) catches late-evening sun in the garden.

A bumble bee nectars in a wild geranium blossom (Geranium maculatum).

Sundrops (Oenothera fruticosa) belong to the evening primrose family.

‘Husker red’ beard tongue (Penstemon digitalis) has maroon stems and leaves.

Monarda ‘Jacob Cline’ begins to open.

Red clover (Trifolium pratense) is a favorite of bumble bees.

Common milkweed (Asclepias syriaca) buds will soon open to provide nectar to monarchs and many other insects.

Garden Damsels and Dragons

A thread-slender eastern forktail (Ishnura verticalis) damsel fly.

A thread-slender eastern forktail (Ischnura verticalis) damsel fly.

The early morning garden is a place of shadows and peace. Cardinals, goldfinches, mourning doves and house wrens ring out their song in neighborhood trees. Already, bumblebees work the flowers — bluebells, bee balm, hyssop and milkweed — buzzing softly.  Almost camouflaged in the deep green shadows, a tiny damselfly perches atop a milkweed leaf. An eastern forktail (Ischnura verticalis), its slender body, less than an inch long, is mint green, blue and black. The wings are folded over its back in damselfly style.

Across the backyard, a much larger dragonfly relative hangs from the edge of a hosta leaf, wings held away from its body horizontally. It is a green darner (Anax junius), one of the largest dragonflies in the world at three inches in length and with a wingspan of more than four inches. Its spring-green head and thorax hide it among the hosta. It “wing-whirs”, or rapidly vibrates its wings to warm up its flight muscles — and that movement catches my eye and reveals its presence.

A common green darner (Anax junius) is one of the largest dragonflies.

A common green darner (Anax junius) is one of the largest surviving dragonflies.

Damselflies and dragonflies are members of the order Odonata, which means “toothed ones”. Unlike the peaceable bumblebees, they are fierce predators, hunting for small insects in the garden and eating many pests. Odonata are descended from some of Earth’s most ancient creatures. Fossils of ancient dragonfly ancestors (Protodonata) date back 325 million years. Scientists believe that bees evolved more recently — about 120 million years ago; the oldest bee fossil discovered so far is about 100 million years old. Both insect families contribute to a healthy garden.

 

Late-Autumn Insects

Last week, the coming winter teased us with snow flurries mixed in with the rain. But, during the first week of November, the temperature rebounded to the 70s. The breeze is gentle, the afternoon sun is hot and a few insects are active in some sun-warmed patches of our backyard.

On the garden’s last purple coneflower, a yellow-green, spotted beetle, similar to a ladybug at first glance, nibbles on the coneflower’s center.  It is a spotted cucumber beetle (Diabrotica undecimpunctata).  And, though it’s a garden pest, it won’t survive the Minnesota winter, so I let it stay. It looks beautiful on the deep magenta bloom.

Spotted Cucumber Beetle

Spotted cucumber beetle (Diabrotica undecimpunctata) on a purple coneflower.

Across the yard in another sunny spot, bright red insects huddle together on a common milkweed pod. They include three different developmental stages, or instars, of the same insect, the large milkweed bug, (Oncopeltus fasciatus).  They use a tubelike mouth to inject digestive enzymes into the pod and then suck out the partially digested plant material.  Because they eat milkweed, they have the same toxicity found in monarchs and other insects that dine on the plant.  When I first noticed them a few weeks ago, I thought they were red aphids until I spotted an adult on the pod.  Over time, they began to grow larger, develop black markings, and become darker red.  Like the spotted cucumber beetle mentioned above, the large milkweed bug is migratory and those still here won’t survive our northern winter.

Early instars of Large Milkweed Bug

Early developmental instars of large milkweed bug (Oncopeltus fasciatus).

Large milkweed bug in developmental stages.

Large milkweed bug in several developmental stages on a common milkweed pod.

The orange shells of Asian lady beetles (Harmonia Axyridis) glow where they’ve settled on the sun-warmed brick of our house and on a few hardy garden plants.  Unlike the insects mentioned above, these beetles survive the Minnesota winter.  They were introduced into the southern United States in the mid-1900s to help control agricultural pests and first appeared in Minnesota in the 1990s, according to University of Minnesota records.  To some people they’re pests because the beetles often find a way inside in the autumn. But, they also eat aphids found on trees, in gardens and on agricultural crops.  The easiest way to distinguish Asian lady beetles from native species is by an “M” or “W” mark (depending on the viewing angle) on the thorax between the head and abdomen.  (More about Asian and native ladybird beetles in another post.)

Asian lady beetle on goldenrod.

Asian lady beetle (Harmonia Axyridis) on goldenrod.

Asian lady beetle on 'Henry Kelsey' rose.

Asian lady beetle on ‘Henry Kelsey’ rose.

2015 Monarch Journey South

Coppery orange and black monarch butterflies glow against the warm, late summer sun.  Monarch migration to Mexico is underway in the northern United States.  According to monarchwatch.org’s peak migration chart, at 45° latitude the greatest number of monarchs will migrate between August 29 and September 10.  In St. Paul, Minnesota, I’ve primarily seen the butterflies floating beneath trees in backyards and along the streets.  A few rest in our garden and nectar on garden phlox, goldenrod, snakeroot, Japanese anemones, black-eyed Susan’s and Joe-Pye weed, which appears to be their favorite.

Monarch resting on white snakeroot (Ageratina altissima)

A male monarch suns itself on white snakeroot (Ageratina altissima)

Monarch resting on one of more than 40 species of goldenrod (Solidago) native to Minnesstota.

A monarch rests on one of more than 40 species of goldenrod (Solidago) native to Minnesota.

A monarch drinks nectar from sweet Joe-Pye weed.

A female monarch drinks nectar from sweet Joe-Pye weed (Eutrochium dubium).

Will this year’s migration numbers be higher or lower than 2014’s?  It’s easy to help scientists track the data by contributing your own monarch migration observations.  Visit learner.org’s Fall 2015 Migration Report Page and complete the short information form for monarchs.  Or, if you’re just interested in how 2015 fall migration is progressing, you can check out the latest information on their Fall 2015 Maps and Sightings page.

Rainy Evening Gift

The backyard was lush and green after the week’s heavy rain. The air felt chilly and damp as I picked up windfalls from our beacon apple tree.  Soaked, bedraggled bumble bees and long-horned bees clung to Joe-Pye blossoms and the undersides of leaves.  Only a few crickets chirped in the unusually cool August evening air.  As I reached into the garden to pull some weeds, I felt a fluttering against my fingers and heard the slightest rustle of wings.  Barely grasping my fingertips was a beautiful green dragonfly —a common green darner.  Its aqua-green thorax and dark maroon abdomen hinted that it was probably a female or juvenile.  I thought it was injured, or perhaps dying. Gently, I held my hand next to some sedum plants.  The dragonfly struggled onto the flower buds and I left it for the night.

Common Green Darner (Anax Junius).

Common Green Darner (Anax junius).

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In the morning, the green darner was gone.  I found no scattered wings or chitin, no other remains in the garden to indicate that it had been eaten. I believe that the sun’s warmth revived it.  Since then, I’ve glimpsed a large dragonfly zooming over the garden on several different days; perhaps it is the same one. I hope that it lives to make the long migration flight south to the Gulf Cost in September.