Presenting: Awbury’s 2018 series on pollinators– from wasps to wind!
Monthly articles will correspond with our programming and our “Pollinators FOUND at Awbury Arboretum” art show and scavenger hunt.
Articles written by La Salle student and Awbury intern Dan Sardaro.
SEPTEMBER 2018 – CRAB SPIDER
Our past three pollinators for the months of June, July, and August have been about the magnificence of butterflies and their essential role in the ecosystem. September marks a shift in insect, as this month’s pollinator happens to be the crab spider which belongs to the family Thomisidae. While most people are frightened by spiders, it is mostly because they are unaware of their role in the ecosystem. Specifically, the crab spider has an interesting role in pollination, one that has both benefits and drawbacks. Karen Singer places the tiny insect on a bright aster flower in this month’s tilework.
The Thomisidae spider family can be found in North America, Europe and Asia, and can be seen in grasslands, meadows, clearings, city gardens, wetlands and other non-forest habitats. The crab spider is a funny looking critter. It has a balloon shaped abdomen that protrudes backwards, and its front four legs are approximately twice the size of the back four. It makes for a unique looking spider, similar to a crab – quite unlike some other kinds of spiders we may think of. The crab spider can also change its color over the course of a few days to match the yellow or white flowers upon which it lives for most of its life.
While we’ve focused on the ways in which bees, flies, or butterflies have helped spread pollen, the crab spider doesn’t help that entirely. In actuality, the insect eats the insects – mostly bees – that come to flowers to pollinate them. Using expert predation skills, the crab spider will spend lots of time on the petals of flowers patiently awaiting prey to come close. Once spotting a bee or fly with their keen eyesight, they will use their deadly venom to tackle the large prey, and successfully gain a meal.
Now this may seem contradictory to the pro-pollination messages of months previous. However, crab spiders are vital parts of the ecosystem. Male crab spiders do ensure that pollen is spread when drinking nectar from various flowers they visit while searching for a female partner to mate with. To add to their pollinating, the crab spider does many other things that make it a key species in biodiversity. Crab spiders provide other animals with a source of food, but they also keep certain insect pest populations in check as well. In the science field, the spiders create silk for scientific materials, produce venom that can be used for medicine, and act as an accurate indicator for biodiversity and ecological health. Next time you’re in a flower garden, look for crab spiders!
“Insect Pollinators.” BeeBristol, BeeBristol Ltd., 2016, www.beebristol.org/pollinators/.
“Flower (A.k.a. Goldenrod) Crab Spider.” Spiders of the HW, Woodland Park Zoo, www.zoo.org/document.doc?id=203.