Sunday, September 26, 2010

Raising a Stink About Stink Bugs!

In the states of Pennsylvania, Maryland, Virginia, and New York, stink bugs have been in the news. People share stories of how the little brown beetles are on their windowsills, in their cars, and on the floor. Farmers are worried that stink bugs will damage their crops.  What are these strange bugs? And why are they causing so many problems right now?

Stink Bugs: What they are
There are really many different kinds of stink bugs. Some stink bugs have always lived in North America. But the one that people are really worried about is the brown marmorated stink bug.

The brown marmorated stink bug, or BMSB, has not always lived in the United States. In fact, they came here from Asia just over 10 years ago. Like many exotic plants and animals, stink bugs were brought to this country accidentally. No one really knows for sure, but scientists guess that the bugs hitched a ride in a packing container from a freight ship.

Stink bugs have a special shape that looks like a shield. They have a sharp mouth part that makes a hole in a fruit or stem. Then, they can suck out the juices. Unlike some other bugs, like monarch caterpillars, stink bugs aren't fussy. They'll eat a wide variety of plants.

Why are they called stink bugs? These insects have a gland that produces a strong odor. Some people have compared the smell to cilantro, an herb, or a bad-smelling pine tree. Everyone agrees that it smells bad! The bad smell makes them less attractive to predators.

Not that there are many creatures lining up to eat stink bugs, that is! In this country, there aren't really any natural predators for stink bugs. Some people report that praying mantises will eat them, but even this great predator can't handle such a large buffet of tasty food. 

The Invasion!
Although brown marmorated stink bugs have been in this country for about 10 years, they are attracting new headlines this year. Why? A warm spring and summer may be to blame.

In most years, brown marmorated stink bugs can only have one generation of eggs in a summer. Because this summer was so warm, however, there have been two or three generations. This means more stink bugs! As the weather starts to get cooler, the stink bugs will try to find warm places for the winter.

And, of course, what's warmer than a nice and cozy house? People are reporting that stink bugs are on windowsills, on porches, climbing up screens, and any other place they can find. And they're tough to manage. When stink bugs are stepped on, they release the bad smell. But most people don't want to use toxic pesticides to kill them. Many are using vacuum cleaners to suck up the annoying bugs.

Studying Stink Bugs
Entomologists, scientists who study bugs, are working on ways to solve the stink bug problem. While people find them annoying, they don't really cause any damage to houses, and don't harm people. But farmers are worried. Stink bugs will leave ugly marks on fruit like apples, which makes the fruit hard to sell. They cause damage to corn and soybeans as well.

While no solutions have been found yet, one thing is sure: Stink bugs aren't going to go away any time soon!

As I was writing this article, I was looking for a stink bug so that I could get a quick picture. Well, I went outside, and this one fell on my head! Uh-oh...it looks like I'll be seeing many, many more of these bugs in the next few weeks.

Tuesday, September 21, 2010

Monarch Caterpillars

This monarch caterpillar is crawling on a milkweed leaf. Why do you think it has two sets of antennae?
Finding a monarch caterpillar is easy--if you know where to look. Monarch caterpillars only eat milkweed. Not many people grow milkweed in their gardens, but you can find it on the edges of fields and meadows. If you find the milkweed, you can find a caterpillar.

Milkweed has big, sturdy leaves. Look for places where the leaves have been bitten. This is a good clue that monarch caterpillars might be nearby! The caterpillars crawl slowly and spend most of their time on just one milkweed plant. They don't have to run or hide. Nothing eats them. The milkweed that they eat makes them poisonous.

In September, the monarch caterpillars here in Pennsylvania are eating and eating and eating. The caterpillar in the picture formed a chrysalis the day after the picture was taken. Once it emerges from the chrysalis, the butterfly will join other monarchs on a flight to a warmer places for the winter.

Saturday, September 18, 2010

Ironweed: A Butterfly Buffet

In August and September, it's easy to find the plant ironweed. Look for it in the places where tall weeds grow--meadows, along the road, anyplace that doesn't get mowed.

Ironweed has deep purple flowers that butterflies just love. Why do the butterflies love ironweed so much? It's all because of the nectar, the sweet liquid inside the flower. Butterflies and bees drink the nectar, and spread the pollen from flower to flower. This helps the ironweed to make more seeds.

If you are lucky enough to find some ironweed, watch it carefully. It's a great place to find butterflies of many different kinds.

Sunday, September 12, 2010

Ghost crabs

This tiny ghost crab blends in perfectly with the sand.
If you visit the beach in the evening, you might see some of these small crabs scurrying by. Ghost crabs can blend in almost perfectly with the sand, which makes them hard to see. They are also very fast. No wonder they are called ghosts!

Ghost crabs don't live in the surf, like mole crabs. Instead, they dig holes further up the beach. Sometimes you can even see them tossing grains of sand out of their holes.

If you want to see a ghost crab, visit a quiet Atlantic beach at twilight or early morning. Find one of the small ghost crab burrows. You can try waiting beside a burrow for the crab to come out. Ghost crabs have to leave their burrows at night to go to the water so that they can wet their gills. They also scavenge for food along the beach, eating just about anything they can find.

Another way to see a ghost crab is to walk along the beach with a flashlight. The light can often catch the shadow of a crab hurrying down to the water. If you are lucky, the crab might pause, surprised by the light. Carefully kneel down to see it more closely. You may notice how its eye stalks stick out. Look carefully at the crab's amazing camouflage.

Ghost crabs are fun little creatures to observe. Try to find some!

Mole crabs: Tiny creatures of the surf

Look carefully at this mole crab. Its head on the right side of the photo. Can you see its antennae peeking out?

Imagine living in a place where the salty ocean water crashes against you. Where every wave pounds against the sand, a place of noise and crashing water. To the tiny mole crab, this is home sweet home.

If you have ever visited a beach, you have probably seen one of these creatures. They are one of the few creatures to live in the area of the beach called the surf zone, where the water meets the sand. Like other crabs, mole crabs have ten legs. If you have ever held one, you probably know that they love to dig!

This digging is what helps them to survive in the surf zone. Mole crabs always dig backwards into the sand. As waves crash over them, they stick out their antennae. Bits of food are always churning about in the ocean water. These food bits stick to their antennae. Then the mole crabs can eat the food!

Digging also helps mole crabs to escape from predators. Sea gulls find them pretty tasty. Larger crabs, like ghost crabs, will also eat them. And people often collect mole crabs to use as bait for fishing.

But mole crabs are more than just prey. They are fascinating little creatures, tiny crabs that live in a harsh place. Mole crabs can be found in many different areas, and have many different names. In some places, they are called sand crabs. They are also called beach hoppers.

The next time you find one, observe it carefully. Can you find its antennae? How many legs does it have? Can you see it digging backwards? These little creatures have a lot to share!