Archive for the 'Insects, Fish, Frogs' Category

Sep 25 2013

The Sun Compass

Male monarch butterfly (photo by Marcy Cunkelman)

A week ago I saw my first and only monarch butterfly of 2013.  Their sudden disappearance is both troubling and saddening.  It’s now possible to imagine a world without monarch butterflies.  We are nearly there.

Last winter’s monarch survey in Mexico showed their population was down 59%, a record low.  There have always been population fluctuations but the trend has been running low and lower since 2004.  Scientists believe that agricultural pesticides and herbicides have reduced available poison-free habitat for butterflies (similar to the bees’ problem), so this spring monarch enthusiasts encouraged people to grow safe-haven milkweed for the butterflies.  It wasn’t enough.

Each species has an intrinsic value.  If, or when, the eastern monarch butterfly goes extinct we will lose its pollination contribution, milkweed symbiosis, beauty, and the amazing adaptations that allow multiple generations to migrate from Mexico to Canada and back.

One of the adaptations that will disappear is this:  Monarch butterflies have a sun compass in their antennae.

Their antennae have light sensors that track the amount of light each day.  According to a study in 2009 by Merlin, Gegear and Reppert, this circadian clock “provides the internal timing device that allows the butterflies to correct their flight orientation, relative to skylight parameters, and maintain a southerly flight bearing, as the sun moves across the sky during the day.”  Migratory monarchs without antennae fly in aimless directions.  Monarchs with antennae always orient southwest.

The monarch’s sun compass was discovered only a few years ago.  Now there are almost no monarch butterflies to study.  The world will be a poorer place without them.

Click here for more information on the monarch’s amazing sun compass.

(photo by Marcy Cunkelman, 2008)

21 responses so far

Sep 23 2013

Green Darner Picnic

Published by under Insects, Fish, Frogs

Common green darner dragonfly (photo by Tim Vechter)

The weather was sunny and cold a week ago when I visited Flagstaff Hill so I was surprised to see over a hundred Green Darner dragonflies patrolling in the chilly breeze.  They were having a picnic.

Each dragonfly faced the wind and hovered, then wheeled away to a new spot and hovered again.  With binoculars I could see thousands of small insects being blown uphill in the wind.  The dragonflies reached out and grabbed them. Their wings glinted orange in the sun.

Green darners migrate south in the fall so I was witnessing a “flock” that happened to stop there for an easy meal.

I don’t have a video of their amazing maneuvers but this one shows how they do it.

 

(photo by Tim Vechter)

4 responses so far

Sep 22 2013

Sleepy Oranges

Published by under Insects, Fish, Frogs

Male Sleepy Orange butterflies in New Mexico (photo by Steve Valasek)

I was captivated by this photo Steve Valasek took in New Mexico.  What butterflies are these?

Chuck Tague filled me in:

These are Sleepy Orange butterflies, Eurema nicippe (or Abaeis nicippe), a common sulphur butterfly in the southern U.S.  They range as far north as western Pennsylvania and occur regularly in a field near Mark and Loree’s place in Rostraver.   Some years they irrupt northward in good numbers.

The two in this photo are males.  They need minerals to reproduce which they’re extracting from wet mud or sand (called puddling).

Sleepy Oranges are common now in Florida.  I’ve raised several this year and collected an egg about a month ago that should emerge from its chrysalis this week.  Here’s a photo of one that just eclosed:

Sleepy Orange butterfly eclosing (photo by Chuck Tague)

 

Google “Eurema nicippe” and you’ll see that the ventral side of the butterfly (underwing, wings closed) is not as interesting as the dorsal side (top, wings open).  Click here to see a Sleepy Orange with its wings open.

 

And why “sleepy”?  There are two theories:  It flies slowly for a sulphur (this notion is disputed) –or– The two spots on its dorsal wings look like sleepy eyes.

 

(photo of two butterflies on mud by Steve Valasek, photo of eclosing Sleepy Orange by Chuck Tague)

3 responses so far

Sep 18 2013

Pickerel

Published by under Insects, Fish, Frogs

Pickerel frog (photo from Wikimedia Commons)

I can tell the habitat is clean in Maine (no acid mine drainage!) because I saw a lot of frogs while hiking there on vacation.

Here’s one that surprised me by the intricate pattern on his brown back. (not my own photo)

Unlike northern leopard frogs which have circular spots on a green background, pickerel frogs have blob-like rectangles.

It’s useful to know the difference because frightened pickerel frogs excrete a substance from their skin that’s toxic to other frogs and mildly irritating to human skin.  Snakes won’t eat them.

No frogs’ legs on the menu with these!

 

(photo from Wikimedia Commons. Click on the image to see the original)

No responses yet

Sep 06 2013

Even One Species Makes a Difference

Bumblebee (photo by Marcy Cunkelman)

In yesterday’s blog I mentioned the pesticide episode in Wilsonville, Oregon last June that killed 50,000 bumblebees.  This prompted me to wonder…

What would happen if just one species of wild bee completely disappeared from an area?

Computer models suggest that the remaining bees would take up the slack and none of the flowers would suffer.  Recent research shows this isn’t so.

Berry Brosi of Emory University and Heather Briggs of University of California Santa Cruz conducted a bumblebee study at the Rocky Mountain Biological Lab near Crested Butte, Colorado where native larkspur is visited by 10 of the 11 local bumblebee species.

They divided the wildflower meadows into 20 square meter plots.  In the manipulated plots, they used nets to capture and exclude just one bumblebee species.  In both the control and manipulated plots their team of Emory University undergraduates followed all the bumblebees everywhere, noting the flowers they visited.

Though bees are generalists they usually specialize in gathering nectar from particular species at the height of their blooming.  If you watch bumblebees on Joe Pyeweed in an August meadow you’ll notice they visit all the Joe Pyeweed in succession even though there are lots of other flowers to choose from. This benefits the flowers because the bees are wearing pollen from their own species.  The researchers confirmed this when they swabbed the bumblebees for pollen and analyzed the results.

In the control plots in Colorado, everything proceeded as expected.  78% of the bees focused on their favorite flower species. Larkspur seed production was normal.

Not so in the manipulated plots. With only one species missing, reduced competition for the flowers prompted the bumblebees to “play the field.”  Only 66% of the bumblebees focused on their favorite flowers.  The larkspur suffered, producing 1/3 less seed.

So the answer is:  If one wild bee species disappears some wildflowers will decline dramatically.

Everything’s connected to everything else.

Read more about the bumblebee study here in Science Daily.

 

(photo by Marcy Cunkelman)

p.s. No bumblebees were hurt during the study.  They were all captured and released.  Quite a feat!

No responses yet

Sep 05 2013

Threats To Bees: Connect The Dots

Published by under Insects, Fish, Frogs

Honey bees on a flower, Slovenia (photo from Wikimedia Commons)

After I met Joan Guerin’s honey bees this summer I became attuned to news that affects them.  An article about the greening of Florida’s citrus trees raised an alarm.

Since 2006 a third of the honey bee colonies in the U.S. have suddenly collapsed and died.  Their disappearance is not merely a honey crisis, it’s a food crisis because the majority of our crops are pollinated by commercially tended honey bees.  Fruits, soybeans, sugar beets, alfalfa… the list of crops is huge and worth over $15 billion.

In the U.S. most news reports say “We don’t know what causes bee collapse. It’s probably a number of factors including pesticides, parasitic mites, inadequate food, and a new virus” yet on April 29 the European Union banned three pesticides for two years to save their bees.  This came 16 years after French bee-keepers concluded that neonicotinoids harmed bees and ultimately caused their colonies to collapse.

In the mid-1990s French beekeepers experienced brutal bee population losses that coincided year after year with the sunflower honey season.  What had changed?  In the mid-1990s French sunflower growers began planting seeds coated with a neonicotinoid pesticide called imidacloprid that protects plants by becoming a systemic insect poison in the roots, stems, leaves, pollen and nectar.  Bees are insects. It ultimately killed them, too.  Even low doses weaken the bees’ immune systems so the EU placed imidacloprid, clothianidin, and thiametoxam on a two year moratorium.

Not so in the U.S. and the U.K.  The Guardian points out that despite evidence from beekeepers around the world, regulators in our two countries prefer to take the chance of not regulating a bad substance rather than accidentally stopping a good one.  Neonicotinoids are used on 95% of our corn and canola and the majority of our bee-pollinated crops and they persist in soil and water even after the treated plants are gone.  Some disturbing events in the U.S. point to additional trouble ahead.

In June a landscaping company in Wilsonville, Oregon sprayed 65 linden trees in a Target parking lot with the pesticide “Safari” that contains dinotefuran neonicotinoids.  They did this for cosmetic reasons — to kill aphids that cause the lindens to dot sap on the cars below — but the result was catastrophic.  The trees were blooming.  50,000 bumblebees died.  The only way people stopped additional deaths was to drape the trees with nets so the bees couldn’t touch them.

Last weekend I read about the “greening” of Florida’s citrus trees.  This is not a happy color change but the sad irreversible death of all citrus trees from a bacteria carried by the Asian citrus psyllid.  Initially the only solution was to chop down infected trees but some farmers decided to keep on farming by nurturing their trees and using intensive systemic insecticides to kill the Asian citrus psyllid.

Imidacloprid, the chemical implicated by French beekeepers and now banned by the European Union, is being used to “save” the citrus groves.

Citrus groves require honey bees to pollinate them.

Connect the dots.  Oh no!

(photo by Mihael Simonič from Wikimedia Commons. Click on the image to see the original)

5 responses so far

Aug 25 2013

A Beautiful Name

Published by under Insects, Fish, Frogs

Snowberry clearwing (photo by Steve Gosser)

While looking for hummingbirds you might find a moth that resembles them.

The hummingbird moth and the hummingbird are examples of convergent evolution.  Both sip nectar from tubular flowers using similar feeding techniques. Their bodies have independently evolved to support their lifestyles and this makes them look alike.  Both have body and wing ratios that allow them to hover, and both have long feeding tubes — the bird’s beak, the moth’s proboscis.

Though we call this a hummingbird moth its real name is beautifully descriptive: Snowberry clearwing (Hemaris diffinis).  As caterpillars they feed on snowberries (among other things).  As adults they have clear wings.

Steve Gosser found this snowberry clearwing at Marcy Cunkelman’s last weekend.

(photo by Steve Gosser)

3 responses so far

Aug 20 2013

Are My Ears Ringing?

iBroad-winged tree cricket, Oecanthus latipennis (phoito from Wikimedia Commons)

This month as I enter Schenley Park and walk up tree-lined Greenfield Road I begin to worry.  With the sound of the expressway on my left and street traffic on my right my ears are overloaded with an additional high-pitched noise.   Are my ears ringing?

I experiment by looking up while listening.  It’s worse.  I plug my ears.  It’s a little better.  The sound of traffic makes it hard to pick out.  What is that high-pitched whirring sound?

August is bug season so I’ve come to the conclusion that the sound is tree crickets, probably one of these (click here).  Maybe the Four-spotted tree cricket (Oecanthus quadripunctatus) who sings day and night and is common along roadsides.

To give you an idea of what I’m hearing, click here for the four-spotted tree cricket and a video with his song.  (The video repeats with a pause at the end.  The sound on Greenfield Road never pauses, there are so many.)

I would try to find these insects but all the online sources say they’re very hard to see — and that’s coming from the experts!  So I’m accepting this as the song of tree crickets and resting assured that my hearing is not in danger.

For more information on tree crickets I recommend this website: Tree Crickets Sweet Sounds of Summer by Nancy Collins at www.oecanthinae.com where you can find close-up photos, songs and videos.

 

p.s.  In settings with less background noise I’ve noticed the tree crickets are in full force this week.

(photo of a broad-winged tree cricket (NOT a four-spotted tree cricket) from Wikimedia Commons.  Click on the image to see the original)

2 responses so far

Aug 15 2013

Cicada Transformation

Published by under Insects, Fish, Frogs

A newly emerged adult cicada pumps up its wings (photo by Kim Getz)

Birds aren’t the only critters who molt in the summer.  Cicada nymphs dig upward from their lives underground (some live underground for 17 years), then climb up high and pick locations to molt into their winged adult form.

A week ago Kim Getz sent me photos of a cicada her family encountered while camping in Clear Creek State Park.  The nymph had decided to molt while hanging on their clothesline.  By the time they noticed, it had already emerged from its exoskeleton and was clinging to it, waiting for its wings to expand and its body to harden.

Time passed.  Its wings became longer.  Not quite ready though.

Adult cicada, still soft but wings are bigger (photo by Kim Getz)

Kim and her family watched for an hour but the cicada had still not turned dark (and hardened) though it moved to a tree trunk.

Cicada moves to the tree to finish its transformation (photo by Kim getz)

Molting is a long and vulnerable process for cicadas.  During the two hours it takes to become a full fledged adult they are soft and edible.  In China there are recipes for stir-fried cicadas though I am unlikely to try them.

To see the whole process in a matter of seconds, watch the animation below by T. Nathan Mundhenk of a cicada molting in Ohio.   The photos were taken at 1 minute intervals for about two hours.  To make the action move quickly he omitted 30 minutes while the cicada rested.

Cicada_molting_animated-2

 

Was Kim’s cicada one of the 17-year cicadas that emerged in parts of Pennsylvania this year?  Probably not.  Adult Magicicadas have red eyes.  My guess is that hers was a Tibicen species.

(photos by Kim Getz, animation by T. Nathan Mundhenk via Wikimedia Commons. Click on the animation to see the full description)

One response so far

Aug 14 2013

Inside The Hive

Published by under Insects, Fish, Frogs

7_bees_tray_of_bees_2239_rsz_kms

Yesterday we saw how beekeepers open the hive.  Today we see what the bees are doing.

Beehives are like dense cities containing food for all the bees and baby nurseries for the next generation.  Since bees don’t live forever the queen must constantly lay eggs to keep the city running.

The queen lives one to five years laying 1,500-2,000 eggs per day after a single (or several) day mating flight.  She is able to selectively fertilize each egg from the stored sperm of 12-15 drones.  The hive lasts as long as there’s a productive queen but the workers have a backup plan.  When they need a new queen they feed selected larvae (laid in queen cups) on royal jelly alone.  Click here for more information on this process.

Below is a photo from Wikimedia Commons of a queen bee with workers.  She is noticeably longer than her workers but is sometimes hard to pick out so beekeepers often mark their queens with a dot of color or a tiny sticker.
Queen bee and some honey bee workers (photo from Wikimedia Commons)

Interestingly the queen does not control the hive but she is treated like a queen. Her every need is met and her reign continues as long as she emits a pheromone that inhibits the workers’ desire to produce a new queen.

In summer workers live about six weeks.  Their duties change as they age.

Young workers start inside the hive near the egg chambers, cleaning the hive, keeping the temperature a constant 93 degrees F, producing royal jelly, and feeding larvae.  All larvae eat royal jelly for a day or two before switching to pollen and honey.  Only future queens are fed royal jelly exclusively.

When larvae develop to the pupation stage, the workers cap the chambers as shown on the frame below.

9_bees_larval_chambers_workers_2245_rsz_kms

 

Joan noticed that a new worker bee was emerging from her pupation chamber for the first time.  I’ve circled her below in green.  The process is a little like hatching as she chews her way out.  It was cool to see a new bee being born.
9c_bees_larvae_digging_out_2246_rsz_kms

 

When their royal jelly glands atrophy, worker bees change jobs.  They build the waxen comb, retrieve nectar and pollen from foragers, store food and guard the hive.

Beekeepers like the bees to build honeycomb on frames separate from the brooding chambers so that no bee larvae are killed during honey harvest.  In the 1700’s beekeepers invented a small hive section called a “super,” that’s placed at the top of the hive and achieves that goal.

Here’s a hive frame containing only honey.  The older comb is darkest.  You can see the honey glistening in the comb.
Honeybees with honey comb (photo by Kate St. John)

 

When they’re three weeks old, summer workers graduate to outdoor foraging.  These are the familiar bees we see gathering pollen in sacks on their legs and filling their crops with nectar to carry it back to the hive.  They travel up to 1.5 miles to find food.

Honey bees stop flying when it’s 50 degrees F and huddle in the hive to stay warm.  They surround the queen and shiver their muscles to keep the center of the hive a constant 81 degrees F during the broodless period in early winter.  When the queen resumes laying they raise it back to 93F.  These are the workers who live through the winter, eating honey to survive.  They consume 30-100 pounds of it!

Though there are 20,000 species of bees on earth the European honey bee is our bee of choice because it forms large hives (lots of honey!) and the hives are perennial.  None of the native North American bees can match this.  They all die off in the winter, leaving only the queen to start over next year.

 

Thanks to Joan Guerin for the honey bee tour.  She is WQED’s Interactive Director, our website’s queen bee.  ;)

 

(queen bee photo from Wikimedia Commons. All other photos by Kate St. John)

 

p.s. Stay tuned next week for more news about bees.

One response so far

« Prev - Next »

Bird Stories from OnQ