Sunday, July 13, 2008
There are four types of hummingbird moths that live in the United States. The two most common ones that you can see in Indianapolis are Snowberry Clearwing, Hemaris diffinis and Hummingbird Clearwing, Hemaris thysbe.
They are called clearwings because they have clear patches on their wings. The wings look like panes of glass in a stained glass window. What is fascinating is they don't start out that way. When they hatch, the entire wing has scales on it, but after their first flight, the scales fall off revealing the clear patches. Here is a link to Bugguide that has a great photo of a Snowberry Clearwing that has just emerged. This loss of scales is possibly to mimic the clear wings of bees, so predators will not bother them.
Their genus name is Hemaris that comes from the greek hemera which means day. Very appropriate considering these are day-flying moths. Most moths come out at night.
Here is a photo I captured of a Snowberry Clearwing. It is a bumblebee mimic, with coloration that will fool possible predators that don't want to mess with the painful sting of a bumbleee. It has a fuzzy yellow body with bands of black. Its wings have more slender margins of scaling along the edges than the Hummingbird Clearwing. The caterpillars sometime feed on Snowberry plants.
My friend John Howard took this shot of the Hummingbird Clearwing, Hemaris thysbe. It has a thicker area of dark scaling on the edge of the wings than Hemaris diffinis. Also, it has a greenish appearance on the body, tinged with red or burgundy. This red coloration, that looks like blood, is where the scientific name thysbe comes from. Apparently, Johan Christian Fabricius, the entomologist that first named this moth in 1775, was a mythology fan. Pyramus and Thisbe are characters in Greek and Roman mythology that met a tragic end. Pyramus was supposed to meet Thisbe and instead found a blood-stained scarf and a lion nearby. Pyramus thought she was dead, so he killed himself. Geesh, talk about an over reaction! Anyway, she wasn't dead, but became so distraught over Pyramus's death that she killed herself, too. Sad story, but beautiful moth, nontheless.
So next time you think you have a hummingbird visiting your flowers, take a closer look. It may be one of these amazing moths!
Saturday, July 12, 2008
So mark your calendars for Sunday August 24th and bring the whole family out to Bug Fest!
Tuesday, July 8, 2008
My friend, John Howard, captured this photo of the miniature beasts. They almost look like little fairies. When you encounter a large group of them on a stem, the whole plant appears to be moving. There are many different species of woolly aphids, all specific to the plants they dine on, and many are considered pests.
Then enters the predator, the Harverster butterfly, Feniseca tarquinius. Oh, it looks innocent enough. They even have a sweet look about them, with their little upturned "nose". The adults are fairly friendly, sometimes lighting on ones finger. I was able to get really close to this one before it decided to fly away. Adults will hang around woolly aphid colonies and lay their eggs amongst the aphids.
When the caterpillars hatch, they ruthlessly snack on the aphids. The scientific name, Feniseca tarquinius, alludes to this behavior. Feniseca means "harvester" and Tarquinius was an evil king who ruled in Rome from 534 to 510 BC and was expelled for his cruelty. Ah, I love scientific names! Here is a picture of the "cruel harvester" from Bugguide. The Harvester is the only known carnivorous butterfly caterpillar in the United States.
Some of the Harvester caterpillars will cover themselves with the carcasses of the woolly aphids they have eaten. They attach the bodies to them with caterpillar silk. The aphids woolly exterior makes them distasteful to most predators, and protects the caterpillar from its enemies. It also works to fool the ants that guard the aphids and keeps the caterpillar from being attacked. Many different species of ants will guard aphids. They protect them in exchange for honeydew, a sweet substance the aphids produce from the plant juices they consume. The ants will stroke the aphids with their antennae and the aphids will release the honeydew. If anything threatens the plant the aphids are on, the ants will come running to bite the would be intruder.
The adult Harvester has a short proboscis, so it cannot reach the nectar in flowers. Instead they feed on aphid honeydew, dung, carrion and mud. Because of this, Harvesters are rarely seen. We do have records of them here in Indianapolis, so keep your eyes peeled and you might be delighted to see this beauty with the interesting life-cycle.
Thursday, July 3, 2008
One is rewarded if they take a closer look. The blossom reminds me of a snapdragon. I love the intricate dark orange nectar guides towards the center of the flower. Articles I have read indicated this plant is pollinated by bees and moths.
Don't let the delicate looking flowers fool you. This is a very deadly plant if you are a tiny rotifer, crustacean or other microbe. Among the leaves are found miniscule pear-shaped bladders. A study showed that one plant with ninety bladders had 270 captured crustaceans!
One can see the bladders in the closeup shot above. The scientific name Utricularia means "little bag" referring to the bladders' shape and function. One may wonder how do the bladders work to capture prey? Each bladder has an opening that has a hanging flap. Surrounding the opening are bristles that serve as triggers. These hairs are baited with an edible mucus that attracts the tiny microbes. When a creature swims by and touches the sensitive hairs, the flap flies open and water rushes into the bladder sucking the unsuspecting prey with it. The door snaps shut and the animal is trapped. The door only swings inward, so the prisoner has no hope for escape. The prey eventually die and the bladderwort uses special digestive cells to produce enzymes that help digest the body. Because the door does not open outward, the parts of the animal that does not easily digest will remain within the bladder and scientists can analyze these to see what was captured.
Here is a website that shows the bladder magnified 100 times. The tiny hairs up close along with the opening of the bladder makes it look like some kind of sea monster. That is probably just what it looks like to a tiny rotifer swimming along, minding its business.
This plant has some other unique survival techniques. In the winter many plants will become dormant and grow back from their root system under the ground. Since the bladderwort does not have a root system it relies on a special overwintering bud called a turion. This is formed at the end of the vegetative shoots and when the plant dies back it falls to the bottom of the pond.
The fine thread-like leaves help the plant by providing a bigger surface area to obtain carbon dioxide. Plants need carbon-dioxide to produce their own food through photosynthesis. Carbon dioxide is scarce in the water, so having a large surface area allows the plant to obtain it more easily.
Bladderworts play an important role plant in the pond habitat. Not only do they feed on tiny microbes, but they also provide food and shelter for fish, frogs, turtles, larger crustaceans and water insects. With strategies to survive the winter, obtain food through flawless traps and through carbon dioxide collection, bladderwort is truly an amazing plant!