A rare find

Despite having a lot of their favorite host plant (swamp milkweed) in my backyard, I have only seen the milkweed leaf beetle (Labidomera clivicollis) a few times.

Milkweed leaf beetles are vegetarian — they prefer the leaves and flowers of just about any milkweed species.  Their bold black and orange coloration warns predators to stay away from a potentially poisonous meal, but these beetles don’t sequester the toxic milkweed chemicals like  the monarch caterpillars do.

This is the only species of milkweed leaf beetle found north of Mexico, and is apparently pretty rare throughout some of its range.  Surprising, since its close relative, the Colorado Potato Beetle is a real pest.  But one researcher found that the larvae of this beetle are highly vulnerable to predation when they occur on milkweed species growing in an old field or prairie where the vegetation is continuous.  They survive much better on swamp milkweed where the plants might be surrounded by a moat of water, a barrier to the roaming predators.  Well then, welcome to my garden.

The one beetle I found in the morning acquired a friend by the evening. I imagine it’s difficult to stay affixed to a large, spherically shaped, slick, waxy object when your legs are too short to get a good hold. The male continually tapped the female’s back with his antennae while trying to jockey himself into position.

“Slip-slidin’ away…You know the nearer your destination, the more you slip sliding away.”  Paul Simon’s lyrics seem appropriate for this couple.

Odd flies

There are plenty of flies, as well as bees, buzzing the garden flowers these days. Macro close-ups of some of them reveal some interesting features.

At first I thought this was a horse fly with pollen on its legs. Looking closer however, it seems to have yellow feet at the terminus of each of its legs.  So I googled “yellow-footed fly”, and a photo of a Tachinid fly (Tachina species) on BugGuide.net came right up.

Tachinid flies are parasites (coexist inside the host) or parasitoids (use the host’s body for development, ultimately killing it) on a multitude of host species:  beetles and beetle larvae, butterfly and moth caterpillars, true bugs, grasshoppers, even other flies.

In addition to his yellow feet, this fly has a yellow face and yellow patches right at the base of the wing.  Forelegs together, cleaning his proboscis before moving on.

Specialized ovipositors enable the female to pierce the cuticle of potential hosts to insert her egg; the larva hatches within a few days to immediately begin consuming organs of the host.  Some Tachinid fly species lay their eggs on the plants consumed by the host so that eggs are ingested and then hatch in the digestive organs of the host.  Sounds gruesome, but these flies are actually good bio-control agents for some insect pest species.  In addition, the adults which feed on nectar, are pretty effective pollinators for many plant species.

Picture-winged flies (Delphinia picta)have a peculiar way of sitting at rest with their wings spread out, slightly cocked like a propeller blade.   They are intermediate in size between a fruit fly and a house fly with brown bodies and matching eyes and legs.  The most distinctive thing about them is the strange markings on their spread wings.

A frontal view shows the fly cleaning its proboscis with its front legs. The black and white pattern on the wings is more clearly visible from this angle.  Picture-winged?  I don’t see it.

Both larvae and adult Picture-winged Flies are saprophagic, meaning they feed on dead and rotting plant material, especially bulbs of onions, iris, rotting fruit, etc.  In fact, they are most often found near garbage dumps and will lay their eggs right in the rotting vegetation to hatch and complete larval development.  The heat of plant decomposition probably helps speed their development along.  The first batch of larvae to develop in the spring will complete their pupal development to adulthood and start the life cycle over again.  But successive generations of these flies are very photoperiod sensitive, with late summer larvae going into a diapause (like hibernation) for the remainder of the summer and winter, finally completing their pupal development the following spring. Pretty smart for a bug!

Pollen collectors

In between rain storms, the pollinators are hard at work in the garden collecting pollen for their nests.  Several species were visiting the Spiderwort, which provides only pollen but no nectar for its pollinators.

Tri-petaled purple flowers of the Spiderwort open one at a time in the early morning, but close in the mid-day heat.

Bright yellow pollen sacs on the tips of the anthers stick up above the petal surface. The solitary stigma (smaller yellow tipped structure at 3 o’clock on the right) will be brushed with the pollen from adjacent flowers as pollinators crawl around the pollen sacs.

Bumblebees (Bombus spp) are so heavy, especially this one loaded with huge orange pollen baskets on its hind legs, that they pull the anthers down when they land on them.  They gather the anthers toward their mandibular jaws with their forelegs to harvest the pollen.

Green sweat bees (Agapostemon spp.) were a little more deliberate in their pollen collection than the rapidly moving bumblebees which spent only milliseconds on one flower.  These are short-tongued bees, dependent on pollen to provision larvae in their ground nests, since they can’t reach the nectar supply in most flowers.

Small syrphid flies (Toxomerus spp) also eat pollen, but they are ineffective pollinators for this flower because their bodies are too small to contact the protruding stigma while foraging on the pollen sacs.  The stigma is on the lower right of the fly’s body at 5 o’clock.

Thanks to the many species of pollinators working these flowers in previous years, there are now about 50 spiderwort plants spread all over the garden from the original 6 that I planted.

this old house — revisited

An earlier post featured an abandoned prairie home at the Lake Johanna Eskers Preserve that dates back to the early 1900s.  I wondered who lived there and what their life was like in those days of the rapid settlement of the Great Lakes region by immigrant Scandinavians.

The old farm house at Lake Johanna esker. Unfortunately (for historians), this house will soon be removed from the property, so that the land can be returned to its completely natural state as a part of the Lake Johanna Esker Preserve.

With a little research and a phone call, my husband was able to learn more about these people, including why they settled in this area in particular.

The Homestead Act of 1862 promised 160 acres of land to immigrant farmers at little to no cost.  This was particularly attractive to European farmers who sought religious freedom, relief from their own economic crises, and land for those who weren’t the first-born inheritors of the family farm.  Norway sent more immigrants to the U.S. than any other European country from the 1820s to 1920s (almost a third of their population), and the family that settled in this area was one of them, arriving here in 1866.

Farm pond at the Lake Johanna Esker preserve.  The climate was so dry during the depression of the 1930s, the pond dried up, and the pond bottom was the only site wet enough for the family to have their vegetable garden.

Why did they come to this area?  Norwegians, like other Scandinavians, immigrated to the Great Lakes area because the topography reminded them of home, and this family, in particular, settled on the Lake Johanna esker because the hills and wetlands were so similar to the land they had left behind.  Of his 160 acres, only about 35 acres of the homestead were actually tillable, which were put into corn and oats production. The rest was too wet, too rocky, or too dry (e.g., around the esker itself).  If the family had settled 1 mile to the east on the flat, rich, deep soil of the tall grass prairie, they would have lived in what is now Bonanza Valley, known for its high agricultural productivity.

The original house had two rooms, one on the ground floor and one above it.

The ancestor who built the house wanted enough room for his growing family of ten children, so he built a two story home, with a kitchen and family room on the ground floor and sleeping quarters for the family on the upper one.  Some food (e.g., a year’s supply of flour) was also stored on the upper floor.  The family bought flour and sugar but little else.

Farming didn’t provide enough income to support his family, so the farmer repaired thresher equipment and utilized his skills as a carpenter for some extra income. Although plowing was still done by teams of horses pulling the plow in the mid to late 1800s, steam-powered threshers patented in the 1830s in the U.S., were used to separate grain from their stalks much more quickly and efficiently than human-powered flails.

Farmers collect these old grain threshers for display as yard art today.

It was a simple life, but a hard one, trying to eke out an existence on this rather unproductive remnant of a glacial river.  But Norwegians were tough, survived, and produced generations of famous Minnesotans, like Walter Mondale and Hubert Humphrey, among a long list of notable Norwegian-Americans.

Going to seed

In the two weeks since I last visited the Lake Johanna Esker property, a few of the prairie plants have bloomed and gone into seed production mode, and a few new species have sprung up from the thin prairie soil on top of the esker.  (For more information about this unusual prairie site and a definition of “esker”, see my earlier post.)

I saw a lot of the Ground Plum (Astragalus crassicarpus) in full flower on May 20, not knowing what it was. Lilac-purple flowers on short stems sticking up from a bush of finely divided leaflets — it looked like some sort of pea plant.

Two weeks later, fruits have formed, although there are far fewer than the number of flowers produced.  Their stems are too fragile to support their weight, so they lie on the ground under the vegetation.  

Dakota and Lakota Native Americans ate the fruit which is full of many small black seeds.  They are green and raw tasting inside right now, though, definitely not fully ripe yet.  Ground Plum is easily confused with “loco-weed” which it resembles but the latter is toxic to livestock.  The vegetation and fruits of this plant were apparently eaten by passing herds of buffalo and native people referred to it as “food of buffalo” or “buffalo bean”.

The nodding bright reddish-pink flowers of Prairie Smoke (Geum trifolium) were seen everywhere on the esker in late May.

Two weeks later, the flowers have transformed into the wispy, plume tails for which the plant was named.

The wispy tails are actually the elongated styles (a tube that carries pollen to the ovary) of the flower.  Lined with minute hairs, each style eventually separates from the flower head carrying a seed aloft to be transported elsewhere on the prairie.

The esker has come alive with spring flowers in the warmish June weather.  We counted (and identified) more than 16 species blooming on this trip.

A small sample of spring flowers in bloom on the Lake Johanna esker.

A succession of bloomers and those going to seed will take place over this summer, and I hope to visit often enough to track those changes.

Why did the turkey land on the roof?

There’s a story here…but we have to start at the beginning.

Tom Turkey struts his stuff in the backyard on a daily basis, morning and evening. This time there were three hens ignoring him, unlike the other day.  He is quite a big bird, at least twice the size of the hens.

Suddenly just at sunset, the three hens perked up their heads, cackled to each other in turkey talk, and one by one in a burst of wing flapping, they flew off into the trees at the back of the yard.  I could hear them crashing and thrashing about back there as they settled on a branch.

I finally found one of the hens — about 80 feet up in a giant cottonwood on a nice horizontal branch. She paced back ad forth trying to find just the right spot to settle down for the night.

But that left Tom with his deflated feathers alone in the backyard.  While I was photographing the hen, I heard heavy wing flapping and foot scrambling on the neighbor’s roof.

What was he doing up there — looking around the neighborhood?

He bobbed his head up and down, paced back and forth on the roof, and suddenly took off.

A burst of flapping carried him just high enough to land on a thick horizontal branch about 50 feet off the ground.

So, apparently, Tom Turkey is so heavy he has to get to his roost in stages, using the neighbor’s roof as a launching platform to get to a high enough branch.

After trying out a few spots on the branch, he finally found the perfect spot for the night.

These spots were typical turkey roosts:  tall, mature trees, with at least one large horizontal branch high off the ground.  The best trees for turkey roosting spots have 30-50 feet of bare trunk below the first branches to foil predators, and are on the east or northeast facing slopes so the birds can warm themselves in the early morning sunlight. There are plenty of oaks in the backyard that meet turkey criteria for roost sites.

A roadside beauty

It truly lives up to its species name — grandiflorus — this tall, showy, Large-flowered Beardtongue.  What makes it even more impressive is that it grows in dense clumps along roadsides, preferring the sparsely colonized roadcuts.

Penstemon grandiflorus growing alongside the interstate in central MN.

It is known by many other names as well:  Showy Beardtongue, Pink Beardtongue, Shell-leaf Beardtongue, Canterbury Bells, and Wild Foxglove.  Large-flowered seems the most appropriate, though based on the size of its floral display.

Individual plants were at least 3 feet tall, making it one of the largest of the Penstemons, with flowers that were about 2 inches long and almost an inch wide.

These flowers should be very attractive to the queen bumblebees out foraging on early summer wildflowers.

As a testament to its adaptability and tolerance, Prairie Moon Nursery’s description of this species is:  “prefers full sun to partial shade, dry-mesic to dry conditions, and poor soil containing rocky material or sand.”

It certainly seems to do well on highway embankments.

Macro-ed

On a cool morning recently, the dragonflies were a bit comatose sitting on the leafy vegetation in the backyard, waiting for some sun to heat them up.  They let me get really close to take full advantage of my macro lens magnification.

The Horned Clubtail dragonfly face resembles a monkey’s, with its widely spaced goggle eyes and big broad lips.  Clubtails are one of only two groups of dragonflies that have their eyes so widely separated.  A tall, plate-like yellow shield between the eyes is typical of this species.

Black bumps between the eyes are motion-detecting ocelli (singular, ocelllus).  Each compound eye contains more than 30,000 light-sensing photoreceptors (ommatidia), giving this highly specialized predator incredible visual acuity in all directions.  For more detail on the marvels of dragonfly vision, see my earlier post on this subject.

From this angle it looks like the dragonfly wears transparent helmets over its eyes.

Viewed from the top, the transparent-looking shields cover only the front of the eye.  I admired the intricate pattern of yellow and black on the head and thorax of this female Horned Clubtail, which allow us humans to tell species apart — but what do they mean to another dragonfly?

Some dragonflies species are like some bird species with sex-dependent color patterns that distinguish male and female from one another.  Horned Clubtail males and females look alike, except for the business end involved in reproduction.

The Horned Clubtail male’s terminal segment (the cerci) have curved spikes resembling cow horns (hence, the species name), used to grab the female’s head during mating. (This shot taken with the Canon 100-400 telephoto lens.)

The Horned Clubtail female’s terminal segment shows short, straight cerci used in egg-laying. (This shot taken with the 90 mm Tamron macro lens.)  It looks like there are fine hairs that project from the surface of the abdominal segments — I’ve no idea what they are for.

Comatose dragonflies make great subjects for macro photography, revealing details of structure I’ve never seen or thought about before.

Orange is the new “blue”

Every time I look out at the goldenrod in the backyard, I see new species of damselflies there.  This one was really striking with his bold orange and black thorax and orange eyes.  I should have mentioned (yesterday) that I have finally begun using the new macro lens I got last Christmas, and what a difference it makes when you’re trying to photograph something that is only 1-1.5 inches long.  (Click on any of the photos below for larger and sharper views.)

An Orange Bluet male…. really! This is not your everyday average blue Bluet.

There are scarlet, cherry, and burgundy Bluet damselflies as well — how confusing.  I wonder why they didn’t call this one the Halloween Bluet instead.

The frontal view provides a better look at his orange and black thorax, and orange and burgundy eyes. What a face!

The females of this species are variable in color:  they might be yellow, green, or blue and black which makes it difficult to ID them.  However, they are usually not seen unless they are being carried around by a male in tandem flight.  Unlike most dragonflies that lay eggs underwater while dangling from a stem above it, the Orange Bluet female deposits her eggs on twigs while immersed in the water, with the male accompanying her in their underwater mating dance.

Those bright orange post-ocular spots look like stop lights. The eyes seem to be three colors ranging from burgundy above to tan below.  Some wickedly sharp spines on his legs are probably used to snare insects.

What a gem!   I wonder what I’ll find out in the goldenrod patch tomorrow.

Damsels in the backyard

In the two weeks we have been gone, our Minnesota backyard has transformed from early spring to early summer.  The perennials have shot up at least two feet, and there are quite a few insects flitting about.  Today, the damselflies were almost as thick as the mosquitoes, as they cruised from leaf to leaf.

Male and female Northern Bluets (I am guessing) congregated like hands on a clock face on the new leafy growth of the goldenrod stems.

Male Northern Bluets are easily recognized by their striking blue patterned bodies. Fortunately, Minnesota is home to only three bluet damselfly species, making ID a little easier.

Female Northern Bluet damselflies lack the blue coloration on eyes, thorax, and abdomen, as well as the signature blue spot at the tip of the abdomen.  Notice how the color of the post-ocular spots (behind the eyes) matches the color of the thoracic stripes on both the male and female.

This is a truly wide-ranging species, found throughout the northern hemisphere in North America, Europe, and Asia, but ranging as far south as India and Mexico. They appear early in the spring and are active until late summer, probably one of the most common damselflies seen.

Damselfly ID guides say that the Northern Bluet is highly variable in its blue color pattern. But this must be another species, and its color pattern doesn’t match any of the MN damselfly species. Help me out here, if you know what this is.

Eastern Forktail Damselfly males were found right alongside the Bluets. Their distinctive green and black thoracic stripes and bright blue spot at the end of the abdomen, as well as slightly larger size, distinguished them from the more common bluets.

Eastern Forktail damselflies are common throughout the north and eastern U.S., ranging as far south and west as Oklahoma.  Thoracic stripes in females may be yellow-green to yellow-orange, but I didn’t see any of these among the Goldenrod leaves, so perhaps they have not emerged yet.  Females begin mating within a few days of emerging, and lay eggs within a few hours of mating. Unlike most Odonates (dragonflies and damselflies), Eastern Forktails are monogamous, and all of the female’s eggs are fertilized by just one encounter with a male.