Stories tagged insect

May
17
2012

How'd you like to wear jewelry made by a bug? Right off the bat, it might not seem like a very appealing idea. But read on, my friend, read on...Caddisfly larva: Imagine this, but made of gold.
Caddisfly larva: Imagine this, but made of gold.Courtesy Wikimedia Commons

I'm a volunteer at the Science Museum of Minnesota, and I'm training for our Aquatic Invertebrates demonstration. I'm a linguist, not a biologist, and I know hardly anything about bugs, so of course I thought it would be neat to learn something about all the little critters you might find in a Minnesota pond or stream. What I didn't anticipate is the utter awesomeness of one particularly enterprising little creature, the caddisfly larva.

Insect larva like the caddisfly are crucial to a stream's ecosystem because they eat dead leaf matter and algae that would otherwise clog up the stream and choke out other life. An insect larva is generally a pretty small, helpless little thing, though, and can make easy fodder for fish and other aquatic animals. The caddisfly larva is no fool, though: it protects itself by building a tiny tube house out of the materials available in the stream, like bits of sand and gravel, tiny sticks, pine needles, and so forth, which are stuck together with silk that the larva excretes.

Of course, a caddisfly is just doing what it's programmed to do, and using whatever materials it has on hand. I mean, hand-analogue. It's an insect; it doesn't have hands. Anyway, the point is that a caddisfly that finds some pine needles will make a little pine needle case, and a caddisfly that comes across some gravel will make a gravel case. That means that if you give a caddisfly larva little chips of turquoise, or pearls, or gold, you get beautiful, jewelry-worthy caddisfly tube "beads". Take a look at some examples.

Sep
11
2011

There I was, sitting on my back porch enjoying the last days of summer, when I heard a sound--"zzzzzZZZZzzzzz"--first once, then again, and finally a third time in short succession. I heard coming from the trees the songs of the cicadas.

The cicada is a large (1-2 inches long) insect with a rather scary looking appearance.

The name cicada comes from Latin meaning "tree cricket" and while they aren't directly related to crickets, they are just as harmless.

About two weeks ago, as I was carrying something out to my car, I noticed a cicada in the process of shedding its exoskeleton to become an adult. You see, a cicada spends years underground as a nymph, feeding on the roots of various plants. After a certain number of years pass by (13 for some, 17 for other species) they emerge from their earthen nursery and climb up the nearby plants to get out of the reach of predators. Afterward, they molt their larval exoskeleton and become an adult. I couldn't believe my luck to have a cicada molting before my very eyes.

When I first noticed it, I saw something pink hanging from my tree. The exoskeleton had already split down the back and the newly adult cicada was climbing out of its old shell, all pink with spring green wings instead of black or brown. Initially, the wings were small green bumps on its back, but as they dried, the wings extended to their normal size. I was disappointed that I couldn't stay and watch its color change while the exoskeleton hardened, because that would also have been cool to see.

Cicadas are a rather delicate and sensitive insect. If the environmental conditions aren't just right with regards to pollution, acidity and temperature, when they emerge the cicadas will be deformed and often sterile. With this in mind, remember that while they might appear to be scary-looking, cicadas are quite harmless and actually a natural sign that the area in which you live is healthy.

Image courtesy of Bruce Marlin
Image location http://en.wikipedia.org/wiki/File:Magicicada_species.jpg.

I'm on a roll, now. Science Friday
Science FridayCourtesy Science Friday
"Water striders don't really stride, they row on the water. But their legs are spindly and don't seem good for paddling. David Hu, mechanical engineer at Georgia Tech, wanted to understand the basic physics of how water striders glide. By filming them stride on food coloring and building his own robotic strider, he found out that the secret to the stride is in the paddle."

Minnesota state officials have announced that ash trees infested with Emerald Ash Borer(EAB) beetles have been found in Minneapolis. This destructive insect pest had already been confirmed in St.Paul in 2009, so officials were not surprised to find that it had spread. A quarantine has been in place for much of the past year, restricting the movement of ash in and out of Hennepin and Ramsey counties. Minnesota has one of the largest concentrations of ash trees in the United States, making it particularly vulnerable. You can see a map here that shows where in Minnesota the EAB has been found, and can read more about how to detect or prevent the spread of this tree-killing pest in ARTiFactor's earlier post.

Want to help track monarchs? The Minnesota Zoo is offering visitors the chance to participate in a monarch tagging project. (Data from tagged monarchs helps scientists learn about their amazing migration.)

August 30, 4 - 5 p.m.
September 6, 4 -5 p.m.
(Dates are subject to change depending on the weather.)

Cost is $10 per person. Children under 10 should be accompanied by an adult. Call 952.431.9273 to make a reservation.