Monday, September 3, 2007

Butterfly Killers

I roamed far and wide all over Adams and Scioto counties Saturday and Sunday, with forays into Brown and Lawrence counties. This is in southernmost Ohio, along the Ohio River, and for the most part the above counties are not well explored from a natural history perspective. While I didn't find anything to rival the Red Phalarope of the previous post, there were lots of interesting finds, and as usual I returned with several hundred photos.

One of the good things about being an inveterate "flower-watcher" is that you'll see all kinds of interesting things on the plants. I would submit that one will learn more about ecology by studying flora - if they also have an interest in animals - than by studying any other branch of natural sciences. Nearly all animals, if not all, depend directly upon plants in some way. Some specialized critters have made absolutely amazing evolutionary strides to become one with the plant world.
This scene unfolded at Chapparal Prairie in Adams County. Pipevine Swallowtails were all over the place, but getting a good photo of one nectaring isn't easy. They constantly flutter their wings when feeding. Not this one. It went to the flowers of this Field Thistle (Cirsium discolor), and didn't spot the leaf-like Praying Mantis. Mantids mimic green stems, hanging perpendicular to the stem of a plant where they've observed lots of insect visitors, usually below nectiferous flowers like the one above. When the pipevine alighted, the mantis pounced.
Its forelegs and other body parts very much resemble stems of plants, and mantids can be hard to spot indeed if they are motionless. Death at the hands of one of these insects would really not be a very good way to go. Once the prey is firmly grasped - escape would be very unlikely at this point - the mantis begins eating it alive. Often starting at the posterior end of the prey item, it eats its way forward. The butterfly, in this case, remains alive for some time but its struggles become increasingly weaker as more of its body parts are consumed.
Mantids have an almost eery alertness to them. Here I've moved in a bit too close and she stopped feeding and gave me a very deliberate evil eye. When I moved off a bit, she resumed feeding. You can see the powerful pincer-like mandibles that it uses to tear into victims. We have several species of mantids, some native and others introduced. I think this might be one of the introduced species, and am sure it is a female as they are much larger. Male mantids have a very risky job when it comes to mating with the much larger females. Upon completion of their duties, they are often eaten by the female if they aren't careful. There may be some parallels to our world here :-)

Crab spiders are outstanding wait and pounce hunters, or ambush spiders. They are very common but easily overlooked due to their excellent camouflage and small size. This one was photographed in Shawnee State Forest and must still be learning. He is on the unopened buds of flowers that probably wouldn't be attracting many insects yet, but the spider shows up well and made for good photography. As a footnote, the plant he is on is Small White Snakeroot, Ageratina aromatica, a very rare plant in Ohio. It is listed as threatened and found mostly in Shawnee.
This is a Crab Spider (probably Misumenoides formosipes but I am always open to learning from the experts). Crab Spiders are absolute master of botanical mimicry. They can change their coloration, chameleon-like, to match the plants that they are hunting upon. This one is on a sunflower and exactly matches the flower's hue. They are ambush hunters that find a popular source of nectar, and await the arrival of an insect. When it lands, the spider lunges. This crab spider has captured a skipper, of which species I am unsure. You can see how strongly fluid-based many insects are. The spider probably didn't catch the butterfly too long before this photo was taken, but it already has sucked out much of the liquid from its prey, drying it out and changing the appearance of the skipper considerably.

1 comment:

Anonymous said...

I'm no expert either, but my first guess on the spider would be the Goldenrod Spider- Misumena vatia