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.

 

About Those Bumblers

My first encounter with a bee was not a happy one.  I was five years old and Mom was mowing the clover-filled front lawn.  I tried to step carefully in the clover, but my flipflop flipped up a honey bee that stung the side of my big toe.  I was hysterical when I felt the jolt of pain, looked down and saw the bee on my toe trying to pull its stinger out. According to Mom, I wailed loudly enough to bring the neighbors outside.  I didn’t care that the honey bee stung out of self-defense and that it would die.  I was petrified of bees and their kin for many years and always avoided them.

Honeybee (Apis melifera) collecting pollen from sedum "autumn joy".

Honeybee (Apis melifera) collecting nectar and pollen from sedum ‘autumn joy’.

It wasn’t until I was an adult and a gardener that I grew to like bees — especially bumble bees. Why bumble bees?  It comes down to temperament.  Bumble bees are large, round, fuzzy, noisy and very intent on collecting nectar.  Their sting packs a wallop, but bumble bees are even-tempered and rarely sting unless they feel threatened.  Many times I’ve accidentally knocked a bumbler out of a flower;  the bee ignored me, flew back into the flower and resumed pollination.  Once, a neighbor was cutting back old hosta stems, squeezed the faded blossoms in the process, and was stung by a bumble bee that was deep inside of a blossom. In decades of gardening, that is the only time she’s been stung by a bumble bee.

A bumble bee (Bombus ----) nectars in monarda "Jacob Kline".

A black-and-gold bumble bee (Bombus auricomus) nectars in monarda ‘Jacob Cline’.

A tricolored bumble bee (Bombus ternarius) rests on red clover.

A boreal bumble bee (Bombus borealis) rests on red clover (Trifolium pretense).

Common eastern bumble bee (Bombus impatiens) on Veronica.

Common eastern bumble bee (Bombus impatiens) on Veronica ‘Red Fox’.

Bumble bees are native to North America, unlike honey bees, which were brought to the United States from Europe.  Covered with thick, soft hair, bumble bees vibrate their strong flight muscles to raise their body temperature and fly at colder temperatures than other bees; as low as 41˚F (5˚C) in comparison to about 57˚F (14˚C) for honey bees.  They pollinate flowers and crops both earlier and later in the season than most species.  I love the sound of their buzzing in the autumn garden, which is much quieter now than the busy insect-filled garden of just two weeks ago. The bumble bees will fly until early November if the weather stays mild.  Then, only the young queen bees will overwinter to create new colonies next spring.  I miss all of the bee activity during the winter and look forward to seeing a queen bumble bee collect pollen and nectar in the first crocus next April.

Common eastern bumble bees are active in autumn, even on cloudy, cool days.

Common eastern bumble bees are active in autumn, even on cloudy, cool days.

Bumblebee “Buzz Pollination”

Last Sunday afternoon was quiet in the garden; too cool for the loud whining of cicadas, and no wind to swish and rattle the leaves.  However, a persistent high-pitched buzzing in the anemones was driving my husband nuts.  Turns out it was the sound of several bumblebees releasing pollen through sonication or buzz pollination.  In sonication, bumblebees, and other native bees, hold onto a flower with their jaws or legs, press the upper portion of their body into the flower and rapidly vibrate their flight muscles to jar loose pollen.  The freed pollen clings to the bee’s furry body.  Some of it is collected in the bee’s pollen baskets to be brought back to the colony, and some fertilizes the next flower that the bee visits.  (The pollen basket is located on the outside of the bee’s back leg.  It’s easy to see when it contains pollen because it will be yellow, orange or red, depending on the type of pollen it contains.)  Buzz pollination is essential to plants such as blueberries, cranberries and tomatoes, in which the pollen is firmly attached deep inside a tubular anther.  However, bumblebees also use it to release pollen in other flowers, such as the Japanese anemones in our garden.

A bumblebee buzz pollinates a Japanese anemone in our garden.

A bumblebee buzz pollinates a Japanese anemone in our garden.

In addition to the buzz pollination video link in the text above, find out more about pollination and bumblebees from master naturalists Paul and Mary Meredith at VictoriaAdvocate.com.