Archive for the 'Insects, Fish, Frogs' Category

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

Aug 13 2013

From Inside The Veil

Published by under Insects, Fish, Frogs

Kate St. John in beekeeping gear (photo by Joan Guerin)

Hello, Earthlings!

Last month I took the opportunity to learn about honey bees from my friend Joan Guerin who has two hives.  Joan loaned me a beekeeping veil and gloves.  That’s me waving from inside the veil.

In this one visit I learned so much about bees that it’ll take several blog entries to tell you.  Today I’ll talk about beekeeping but barely touch the surface.

First rule, if you’re allergic to bee stings this is not the job for you!

Gear:  Honeybees only sting to protect their hive or if they get trapped in your clothing.  Since beekeeping disturbs their hive, wear the gear.  I cinched mine tight to prevent wayward bees from exploring under the edges.  Joan is so familiar with her bees that she didn’t wear gloves and her hands were just fine … except that a lone bee walked up under her bell-bottom pant leg, panicked, and stung.  Joan calmly removed the stinger and moved on.    (Many old-timers don’t even bother with gear.)  The honeybee that stings, dies of the effort because the stinger yanks off part of her body.

Smoke: Thousands of years ago people learned that bees are less likely to sting if you blow smoke at the hive.  When bees smell smoke they think the forest is burning so they rush to the honeycombs and chow down in case they have to evacuate soon.  Smoke also masks their alarm pheromones so if a lone bee stings you, the rest don’t smell the alarm and join in a stinging campaign.

Below, Joan’s smoker burns paper and wood chips.  When closed it looks like a teapot with a bellows on the side.
Making smoke to calm the bees (photo by Kate St. John)

 

Joan started by blowing smoke at the entrance of the first hive.  The entrance is a small space near the bottom, out of view of the camera.
3_bees_joansmokesthem_2225_rsz_kms

 

Man-made hives are sectional so the beekeeper can easily open them to check the bees, retrieve bee products and rearrange the sections if necessary.  Rearranging becomes necessary because the queen bee moves upward in the hive as she lays eggs in chambers prepared by her workers. If the queen gets close to filling the available space the colony splits and half of them fly away with a new queen. (Not good for the beekeeper!)

To keep the colony intact, beekeepers move the queen’s section to the bottom and add another section for the bees to use. Or the beekeeper can split the hive into a second stack and even provide a new mail-order queen, though the bees can make a new queen on their own (of course).

The Hive Tool: Opening the hive is not a simple matter.  The bees seal everything with propolis so beekeepers use a crowbar-like tool, 10 inches long, called a hive tool (photo from Brushy Mountain Bee Farm).
Hive tool (image from Brushy Mountain Bee Farm)

After prying off the outer lid Joan showed me the inner cover. The center hole is an entry into the hive below.  On the left is the notch that’s an exit to the outside world.  Only the older workers go outdoors.
4_bees_lid_off_2243_rsz_kms

This lid is the only horizontal interior section.  Everything else inside the hive is vertical.

Each section has no bottom and holds 8 to 10 frames that slide in from the top.  The frames have panels with very slight hexagonal surfaces to give bees the hint to “Build here.”   The frames are vertical and close to each other for maximum surface area.  The bees build their hive on a vertical surface in the dark just as they would in a bee tree.

Here’s the top of the first section with the lid off.  Joan has just “smoked” them so the bees are retreating to the inside.
5_bees_lid_and_tray_off_2236_rsz_kms

 

Joan pried the frame edge and lifted one out.  Here’s the same area with one frame missing.  The frames are very close together but that doesn’t matter. Bees are tiny.
6_bees_section_out_2229_rsz_kms

 

Each hive contains one queen, thousands of female workers and a few male drones.  When the frame comes out it is covered with bees.  Almost all are female workers.  I saw a few drones but ran out of time to delve deep into the hive and find the queen.
7_bees_tray_of_bees_2239_rsz_kms

Tomorrow I’ll show you what the bees were doing inside.

(photo of Kate St. John waving, by Joan Guerin. All other photos by Kate St. John)

6 responses so far

Aug 11 2013

Extra-Spectacular

Published by under Insects, Fish, Frogs

Pandorus Sphinx moth (photo by Monica Miller)

Extra-spectacular.  That’s how BugGuide.net describes the Pandorus Sphinx moth.

When you see this 3.5″ to 4.5″ moth it stops you in your tracks.  It’s huge, beautiful olive green, has black and pink highlights, and is as big as the palm of your hand.

Years ago I saw my first Pandorus Sphinx month perched on an end-wall of the Greenfield Bridge over the Parkway East.  What was it doing there?

Pandorus Sphinx larvae feed on grapevine and Virginia creeper leaves.  There’s a lot of invasive grapevine draping the hills near the bridge so that moth may have spent its caterpillar days there.  Perhaps it was a female waiting for night to fall so she could emit pheromones which the males “smell” and follow upwind to find her.

I’d love to see the caterpillar some day.  They’re extra-spectacular too — bright green or burnt-orange with orangy or white spots.  Their third thoracic segment is oversized so they can draw their heads and first two segments into it for protection.

Here’s a rust colored caterpillar with his head drawn in.

Pandora Sphinx Moth caterpillar, Moraine State Park, 2008 (photo by Chuck Tague)

August is a good month to see these moths and their larvae.   I hope I get lucky.

And thanks to my personal bug guides, Monica Miller and Chuck Tague, who took these pictures.  They are both very lucky when in comes to bugs.

 

(moth photo by Monica Miller, caterpillar by Chuck Tague)

One response so far

Jul 28 2013

Predatory Ladies

Published by under Insects, Fish, Frogs

Ladybugs hunting aphids (photo by Kate St. John)

Ever since I wrote about aphids a few weeks ago, I stop to look for their predators.

Last weekend I saw ladybugs in action.  They’re such great predators of aphids that Asian lady beetles were imported in the 1970′s as a biological pest control.

I watched them make a dent in the aphid population on joe pyeweed.  One lady beetle absolutely ran from stem to stem checking for aphids.  She abandoned flower heads with too few aphids and even turned back when she found a stem completely coated in aphids (too many?).  I saw her chase an aphid, then finally settle down to work on this flower head.

This must have been a good site.  How many ladybugs can you count?  (More than appear at first.)

Notice that these ladies are spotless.  They’re the Asian species.  Our native ladybugs always have spots and are in decline because the Asian lady beetles carry a fungal parasite that kills the natives.

The bad news is that Asian ladybugs are overtaking the natives.  The good news is that we have ladybugs and they’re eating the pests.

Good job, ladies!

(photo by Kate St. John)

No responses yet

Jul 25 2013

Great Golden Digger

Published by under Insects, Fish, Frogs

Great golden digger wasp on spreading dogbane (photo by Kate St. John)

I always look for birds when I’m outdoors but they just aren’t as conspicuous as the bugs are in July.

Last weekend on the Montour Trail I found a large black-and-orange wasp feeding on spreading dogbane.  It attracted my attention because it was huge and had bright orange legs and abdomen.

My search at bugguide.net identified it as a great golden digger wasp (Sphex ichneumoneus).

The name is apt.  They are huge, golden (their foreheads are gold!), and they dig a hole to create their nests.

Great golden diggers are solitary.  To make a nest a female digs a vertical hole with lateral chambers.  For each egg laid, she captures and paralyzes a katydid or grasshopper, then drags it into one of the chambers, lays an egg on it and seals the chamber.  The larva feasts on the paralyzed insect and emerges as a wasp.  Read more of this amazing story here.

I tried to get a good photo showing her orange body.  Below she flaps her wings to perch on an unstable flower.

Great golden digger wasp (photo by Kate St. John)

 

Was I afraid she’d sting me?  No.  She was too busy feeding.

Later I learned I had nothing to fear.  Though intimidating, this species is not aggressive.

 

(photos by Kate St. John)

p.s. Check the video link at “Art from Hershey, PA”s comment below to see what the digger’s nest looks like from above.

6 responses so far

« Prev - Next »

Bird Stories from OnQ