The Goldenrod Crab spider:
Scientific Name: Musumena Vatia aka: Flower Spider
Look closely at a yellow flower and you may see the Crab Spider — also called the Goldenrod Spider — sitting on it!
This hunting spider has a short, broad abdomen and legs that are held outstretched to the side that enable it to move sideways, forward and back just like a crab.
The male Crab Spider is 1/8 inch long, and the female is 1/4 inch to 3/8 inch long. Usually white with red stripes on the sides of the abdomen, this spider can change its color to yellow. The Goldenrod Crab Spider (this week’s bug) is a master of disguise. These spiders change color by secreting a liquid yellow pigment into the outer cell layer of the body. On a white base, this pigment is transported into lower layers, so that inner glands, filled with white guanine, become visible. If the spider dwells longer on a white plant, the yellow pigment is often excreted. It will then take the spider much longer to change to yellow, because it will have to produce the yellow pigment first. The color change is induced by visual feedback; spiders with painted eyes were found to have lost this ability. The color change from white to yellow takes between 10 and 25 days, the reverse about six days. This particular species of spider can be found in almost all parts of the continental US. The Goldenrod Crab Spider is an ambush spider, jumping on their prey. They do not construct webs.