We had a fruit fly episode at work last week.  We trapped and did not release.

It all began when Emily came back from maternity leave and discovered a co-worker had left old food in her office refrigerator.  Emily carefully wrapped up the rotting fruit and threw it away but a couple of fruit flies escaped.

For two days we barely noticed them.  A single fruit fly would appear at mealtimes and disappear afterward. By Thursday however the single fruit fly became two and one of them never went away.

I’m no expert on fruit fly identification but these seemed to be Drosophila melanogaster nicknamed “vinegar flies” because they’re especially attracted to vinegar, a by-product of the rotting fruit which is their favorite food. Here’s a close-up from Wikimedia.

D. melanogaster is well studied.  For more than 100 years it’s been the subject of genetic research because its traits are easy to parse out and it reproduces quickly.  At warm room temperature (77^oF) a newly laid egg becomes a breeding adult in only 8.5 days.  The adults live about three weeks during which time the females can lay 100 eggs per day.   The D. melanogaster population can quickly get out of hand if you don’t have swallows and flycatchers around to eat them.

Fortunately Emily knew exactly what to do.  She taught us how to make vinegar traps, as in…

1. Pour a little vinegar in the bottom of a cup
2. Cover the top, leaving only a small hole.  We used tape to cover the cups.
3. Wait for the flies to fly in and never come out.

Emily supplied the plastic cups.  We supplied the tape and vinegar.   All we had was balsamic vinegar — very dark.

The first photo shows what our traps looked like from the side.  The photo below shows them from the top. Because we used tape, the trap hole is a triangle.

My traps caught nothing for hours. Emily’s caught many.

When she left for the day Emily threw away her traps so the next day was quite a success for mine.   Using their keen sense of smell, the flies flew further to find the vinegar.  In a matter of seconds they could find a new food source down the hallway, the equivalent of a human smelling food and traveling seven miles.

My traps’ success is shown below with three circled fruit flies.  And what are those tiny dark specks near the flies?  Eggs!

Without birds to eat the flies, vinegar traps will have to do.

(close-up of D. melanogaster from Wikimedia Commons, all other photos by Kate St. John)

Last Saturday the Wissahickon Nature Club celebrated its 70th anniversary with a picnic and nature walks at Mingo Creek County Park.

I was fascinated by the butterflies we saw because most of them are mysteries to me.  I’m able to identify only a handful including this mimic of all mimics, the Viceroy.

In northern North America(*) adult Viceroys closely resemble Monarch butterflies because Monarchs are poisonous. The Viceroys who don’t look poisonous are eaten.  Those who do, live and reproduce.  This predatory pressure reinforces mimicry generation after generation, a form of evolution in action.

How closely does a Viceroy mimic a Monarch?  I’ve marked a photo by Marcy Cunkelman with an arrow showing the black “smile” on the wings that tells the difference.  Viceroys have it, Monarchs don’t.

Viceroys are even mimics in the larval stage.  Their caterpillars look like bird poop on a stick, as you can see on this one found by Dianne Machesney.  Not only does he look like poop but I think those obvious antennae are false.  Aren’t they at his back end?

Click on the photo above to see an even “poop-ier” looking Viceroy caterpillar.
No matter what life stage, these butterflies are not what they appear to be.

(perched butterfly photo by Chuck Tague, photo with arrow by Marcy Cunkelman, caterpillar photo by Dianne Machesney)

(*) Where Monarchs are rare in Florida, Georgia and the Southwest, Viceroys mimic the Queen butterfly.

From mid-June through mid-September Great Spangled Fritillaries are the most common Fritillary in the eastern United States. Here are two in Marcy Cunkelman’s garden.

The word fritillary fascinated me. What does it mean and why does it name a whole group of butterflies?

It comes from the Latin for dice-box.

The butterfly is named Fritillary because it has a brown spotty pattern reminiscent of dice.

A family of lilies is named Fritillaria because they are brownish with a checkered, spotty pattern. Here’s Fritillaria meleagris:

They’re both dice-y.  😉

(photo of Great Spangled Fritillaries by Marcy Cunkelman. photo of Fritillaria meleagris from Wikimedia Commons)

In the past week my cat and I have had some excitement when I turn on the kitchen light in the morning.  Sometimes we’re startled by a 100-legged bug that zooms across the floor to hide.  I jump back and Emmalina (Emmy) jumps forward to chase it.

Eeewww!  I’m repulsed by house centipedes but a book called Despicable Species by Janet Lembke taught me these critters help me indirectly.

House centipedes (Scutigera coleoptrata) are nocturnal raptors, the owls of the bug world.  They eat a wide variety of live prey including spiders, silverfish, ants, termites, bedbugs and cockroaches which they catch by running them down.  For this they need to be fast.

With rigid bodies their speed comes from their legs.  Amazingly house centipedes don’t have 100 legs.  Adults have 15 pairs of very long jointed legs (yes, only 30) with extra muscles that allow them to achieve a top speed of 1.3 feet per second very quickly.  The two longest legs in the back mimic antennae and the two shortest in the front are modified to sting and kill their prey.  The stingers sound scary but are very small and harmless to humans.   House centipedes can even lose a few legs to get away if captured.

Because they don’t have wax on their exoskeleton, centipedes must rest during the day in damp, dark environments so they don’t dry out.  They prefer basements and crawl spaces (I have both) and are sometimes found in the bathtub because they look for a damp place to rest.

Like many other bugs, house centipedes have a spurt of visibility in the spring.  It’s the sight of all those legs that make my scalp crawl.  I couldn’t even use an illustration of the entire bug for this post because I can’t bear to look at all those legs.

It’s reason against emotion.  Now that I know they help me, I am trying very hard not to say “Eeewww.”

(close-up of a house centipede from Wikimedia Commons. Click on the photo to see the original)

6 April 2012

Word on the street is:  It’s going to be way too easy to catch Lyme disease this year.  That’s because it’s a boom year for black-legged ticks (also called deer ticks) and a bust year for their preferred blood host, white-footed mice.  Since mice are scarce the ticks will look for other hosts including us and our pets.

Lyme disease is caused by a bacteria (Borrelia burgdorferi) transmitted by the bite of a black-legged tick.  Black-legged ticks must have a blood meal in order to transition to their next life stage.  Any tick that’s acquired the bacteria from a prior host will give the bacteria to its next host.

The nymph stage is the most dangerous to humans because it is so hard to see.  It’s a critter the size of a poppy seed that has all the time in the world to walk up your body in search of a sneaky place to latch on and suck your blood.  If it bites you for more than 24 hours you have a higher chance of getting Lyme disease.

You never, ever want to get Lyme disease.  As my friend Dick Martin says:  “About a week after the infection, you will be hit by instant old-age.  Aches, flu-like symptoms, etc. are bad.  I speak from experience.”   The disease is debilitating with life-long effects if you don’t catch it early.

It’s way too easy to pick up ticks during any one of these activities:

• Unwittingly visit infested areas (notice red X’s at this link).  Interestingly, the infection zones for Pennsylvania are more widespread than the tick infestation map.
• Sit down outdoors on anything other than pavement or furniture.
• Walk off trail near a stream, seep or wet zone.
• Step into leaf litter.
• Allow grass or plants to brush against you.

So you shouldn’t go outdoors?  Wrong!   Your best defense is vigilance:

• Wear light-colored clothing that covers your skin — long pants and a long-sleeved shirt with collar.  Pull your socks over your pant cuffs.  I can tell you this outfit is eccentric and stifling in hot weather but it’s worth it.
• Spray your clothing with bug repellent, especially your boots, socks, pants. Read about what to use here: Today Is Spray Your Clothes Day.
• Check for ticks.  Check your clothing while you’re in the woods.  (That’s why you wear light colors.)  Check before you get in your car.  Check your body and scalp (take a shower).
• Remove ticks with precision tweezers. 
• Know Lyme disease symptoms and get treatment early.  Dick Martin says,  “Don’t count on the bull’s-eye red rash; I skipped that indicator.  If you pick off a blood-filled tick, ask your doctor for a prophylactic dose of an approved medication.  If you hesitate for the week, you have a tougher regimen of medication.  If you somehow ignore that, you have more serious, long-lasting effects.”

Read here for more information on black-legged ticks and Lyme disease.

Hawaii is the only state where Lyme disease has never been reported.  Plan accordingly.

(image from CDC.gov.  Click on the image to read more about black-legged ticks and Lyme disease)