The Phylum Arthropoda contains creatures that have a skeleton on the outside and jointed legs. You have seen many of the members such as spiders, centipedes, millipedes, flies, beetles, and crabs. This Phylum is split into different Classes and spiders, insects, centipedes and millipedes all have their own.
Two qualities make an insect an insect. First, they have 3 body segments, a head, thorax, and abdomen. Second, they have 3 pairs of legs. All insects go through “life stages” where they are one form and then metamorphose into another form. A good example of this is when a caterpillar changes into a butterfly. Often, each life stage uses different types of resources. A caterpillar will crawl on the ground and eat leaves, but a butterfly will fly from flower to flower drinking nectar. This is important because when scientists are trying to conserve certain species, they must conserve the resources that each life stage uses.
Here in Point Reyes...
A commonly seen caterpillar in the fall is the Yellow-spotted Tiger Moth, which is black with a yellow band through the middle and has long white hairs jutting up all over its body. The spring may provide some excellent opportunities to find butterflies in the park. You may see the Pipevine Swallowtail butterfly on woodland borders or the Spring Azure butterfly anywhere within the park. In the summer, beetles are more easily spotted along the ground when the vegetation is dry and brown. Jerusalem crickets are plump and plentiful along the coast and many species of snakes feed on them.
Spiders are often seen, but not as often identified. A couple of the more conspicuous ones include the flower spider (Misumena vaita), which looks like a small crab and hangs out in flowers. It can change colors to match its surroundings so that when an insect, often a bee, lands on the flower it can attack and eat. The red-backed jumping spider (Phidippus johnsoni) is found at Point Reyes and even included in a state-wide study. They are black with red spots on their abdomen and they jump like their name implies. If you see a beautiful web, check the middle for Cyclosa conica. This classic-looking spider decorates its web with dead victims to hide amongst as camouflage.
As you can see, Point Reyes National Seashore provides habitat to a large variety of arthropods. Keep your eyes open and point them down once in a while!
Text by Kristen Truchinski
Myrtle's Silverspot Butterfly Video
Last updated: May 8, 2020