Friday Field Notes: A Little Face on a Quaking Aspen Leaf

Last Friday, September 6th, I enjoyed a leisurely hike up to the Blodgett Canyon Overlook in the Bitterroot National Forest. The warm sun was muffled by a scattering of grayish clouds, allowing the temperature to stay below 85 degrees. It was a perfect day for a short adventure.

On the descent of the hike, I stopped next to a four-foot-high quaking aspen tree alongside the trail. I reached for a leaf, and placed it in my hand. My fingers followed the contours of its outline, amazed at its symmetry. I stepped back to look at the whole tree, when my fiancé said, "Hey, look at this!" Between his fingers he held another aspen leaf. I glanced at the leaf, but didn't notice anything, and looked back at him questioningly. He said, "Look closer." As I stared at the leaf, I was taken aback by the caterpillar that lay on the leaf before me. Two yellow ovals on the top of its head created the appearance of eyes, and a yellow and brown line across its thorax unveiled a smirk (depending on your perspective). Its green body with subtle blue dots blended in perfectly with the leaf.

I learned that this caterpillar was a Western Tiger Swallowtail, or Papilio rutulus, and that it is common to western North America. They are often seen in woodlands, riparian areas, and urban settings. These caterpillars feed on the leaves of hardwoods, such as poplar, willow, alder, maple, cottonwood, and quaking aspen. The Western Tiger Swallowtail caterpillar, or larva, will molt about five times before pupating (that is, evolving from a caterpillar to an adult insect--in this case, a butterfly). For butterflies, the pupal stage is called chrysalis. When the caterpillar has reached its full size, it produces silk to adhere itself to a leaf or limb of a tree. At this point in the process, the caterpillar will shed its skin one last time, leaving a hard skin, called a chrysalis. The caterpillar will stay in this stage until it is ready to turn into a butterfly.

In the summer, a butterfly can emerge within fifteen days of pupating, but if it pupates in the fall, it must wait until springtime, when the temperature begins to rise. The beautiful butterfly that emerges from the chrysalis has yellow on its forewings, a thick black border along the wings' outside edge, and a hint of orange and blue on its tail. Its wingspan is ~8.5 centimeters. Females will lay up to 100 eggs onto the protective underside of leaves, and within four days or so, they will hatch, introducing a new group of smirking caterpillars into the natural world.

VNS May Field Trips: Insects, Part 2--Beetles!

There are 450,000 species of beetles, and they make up 40% of all insects. So, I hope you'll forgive me for not being able to identify all of the species we saw on our field trips! We caught some amazing specimens: brightly colored ones, iridescent ones, and just plain adorable ones. The kids were superb insect collectors, and only a few bugs were accidentally crushed in the excitement (one of which, I will admit sadly, was a sneaky common cricket that I was trying to recapture). I will do my best at telling you what I know about the beetles I got pictures of--or about beetles in general.

Here are the basic body parts of beetles, which I will refer to below. What isn't illustrated in the diagram is a section called the pronotum, or a portion of the front-most surface of the thorax. The shape and size of this feature is often very helpful in the identification of beetles.

Beetle #1: The lime green one on a pencil. 

Truly, I do not know what kind of beetle this is. It was a vivid, lovely color, though, and the kids who found it were ecstatic. 

 Beetle #2: The funny-colored lady beetle. Or, what reminds me of a Colorado Potato Beetle.

 This one came and landed right on my bracelet. He is shaped just like a lady-beetle--and there are 150 species of "ladybugs" in the U.S., so he very well could be one!

Entomologists think that lady-beetles may have spots to warn predators that they taste bad and can make them sick. See, ladybugs make a little bit of poison--just a little--and birds may be able to learn that a spotted beetle equals a terrible taste and illness.    

I'll admit, being a girl from a farm, my first thought was, wow, what a funny little, spotted Colorado potato beetle. Thankfully, this guy's pronotum and coppery-brown color set him off as something different. He's lovely, isn't he?

Beetle #3: A metallic-colored ground beetle (perhaps?)

 

If you Google the colors of this beetle (metallic green and copper-brown), you will get results for the notorious Japanese beetle--but this guy's colors are inverted and his shape is not the same. 

Do you know any of these beetles? If you do, tell us about them in the comments! We'd love to know!

VNS May Field Trips: Insects, Part 1.

The insects station is, by far, the most active one in the spring. Sure, the hikes have lots of walking, but at the insect station, we wander around, run with nets, dump and scoop bugs with caution and speed, and work hard to draw and inspect. We don't really try to ID, but, as you will find, it is difficult not to know what to call a specimen we find. Naming something, however, is only part of the process, and  being able to describe it or draw it in detail is also important. Simply observing and marveling at something is worthwhile, too!

Christine W. helping with a multitude of bugs!

After the sometimes cold and often surprising weather of the first two weeks of field trips, things warmed up, the sun came out, and jackets were shed or tied around waists and we were able to focus on the bugs in the nets and crawling around on us. At least, in theory, we could focus. Sometimes we had insects in a bunch of places, which led to a multitude of things going on all the time.

This little guy is an Anthocharis stella, or a Stella orangetip, butterfly. Along the Pacific coast, the subspecies is a Sara orangetip, and the Stella was thought to be a subspecies; but recently, scientists discovered that the two (Sara and Stella) will cohabitate without hybridizing. You can tell the difference, I've learned, by the color of their marbeled underwing: Saras are darker grey-green, and Stellas are pale mossy-green.

In general, though, you can just call them all orangetip butterflies, if you'd like.

They are such beautiful little creatures! Variations of this species are found all over the world. In some, the females are white, like cabbage moths. In others, like these, both males and females have orange tips, but males have more pronounced dark borders on white wings, while females have a yellowish tint and lighter mottling on the underside of their wings.

Isn't that wing marbling neat?

Look at this grasshopper we found! He was bright green with brown legs, wings, and eyebrows. No really--he had eyebrows! It was very cool.

Now, there are at least 11,000 verified species of grasshoppers (Kevan 1982; Günther, 1980, 1992; Otte 1994-1995; subsequent literature), but still, I'm going to go out on a limb and try to identify him. I think he's some sort of band-winged grasshopper. I didn't stretch out his wings, but if I had, I bet I would have found bands of color on them.

The kids absolutely had a blast! Look at these little naturalists!

Boxelder Bugs

The Boxelder bug (Boisea trivittata)

I started typing this post about all of the autumn-time plants I’ve been seeing around Greenough Park, but I was interrupted when a boxelder bug crawled across the desk and onto the keyboard. 

There has been an influx of them in the office. They are crawling on walls and bookshelves, down the stairs and up the doorways. I have seen half a dozen today alone. I have heard folks talking about them--and not everyone knows much about them. 

Boxelder bugs are named for their love of boxelder trees. The bugs are attracted to the female boxelder trees, which are the seed-bearers that can be identified by their long slender blossoms that hang down and produce seeds similar to maple seedpods—the paired “whirlybirds.” Boxelder bugs will, to a lesser extent, also feed on maple, ash, and sometimes fruit trees. They use their ‘beak’—a proboscis—like a straw to suck juices out of plant material (predominately from seedpods), but they don’t seem to cause any damage to the trees.

 I can see a female boxelder tree out the east window of the office, its seedpods hanging in dry clusters that will endure through the winter. The windowsill is crawling with bright boxelder bugs of all life stages, sunning in the mottled morning light.

Sara C. 2011

The nymphs, or immature bugs, are bright red with round bottoms, which become more elongated and marked with black as they mature. The adults are a half-inch long, flat-topped and predominately grayish brown or black, with parallel red stripes on their thorax, a red abdomen, and red cross-markings on their wings. The bugs have big eyes and long, segmented antennae.

I don’t mind boxelder bugs; they don’t bite, or sting, or stink, or eat houseplants. They find ways into buildings, but don’t damage them. They just crawl around, looking for a nice place to sleep through the winter, and then come spring they go back outside to mate. They are considered pests simply because they are a plentiful, and therefore sort of a nuisance. (The boxelder bug at my desk is actually quite entertaining, and seems to enjoy following every cord from my computer and back.)

The boxelder bugs mark a change in seasons, a reminder that summer will come to an end. Other than that, they are absolutely harmless.

Though remember: don’t squish them, they’ll stain things.

References:

 “Boxelder bugs and Conifer Seed/Leaffooted Bugs.” Montana Integrated Pest Management Center, 1997.  http://ipm.montana.edu/YardGarden/docs/boxelderbugsconiferbugs-insect.htm 

“Boxelder Bugs vs. Lady Bugs.” The Eclectic Scientist! June 23, 2010. http://angelasentomlabnotebook.blogspot.com/2010/06/boxelder-bugs-vs-lady-bugs.html

Swan, Lester and Charles Papp. The Common Insects of North America. Harper & Row Publishers, Inc: New York, 1972. p126.

See also: Spotlight on Boxelder Tree, April 2010