I spied a very quiet bumblebee sitting near one of the lupines yesterday. Odd behaviour for midday.
I looked closer. Ooops. The bumblebee had stumbled into the clutches of a large goldenrod crab spider.
Crab spiders are ambush predators. They wait for insects to visit flowers in search of pollen and honey.
They blend in well which makes them successful hunters. Using pigments in their body they can even change colour, from white (often with pink stripes or blotches) to yellow and back again. According to the Encyclopedia of Life it takes 10-25 days to turn from white to yellow but only about 6 days to turn from yellow to white.
So: Bumblebee arrives. Spider grabs it with her outstretched legs. Injects venom through her fangs. Paralyzes bumblebee.
Once the prey is subdued the spider injects digestive enzymes into (or onto) the victim’s body, liquefying the insides. Then it slurps up the liquid. Nothing like a high-powered protein shake for lunch.
How long did it take from start to finish? Hard to say. When I first discovered the bumblebee she was pointing head-first into the flower. When I checked again about 30 minutes later the spider had manoeuvred the bee around so that its head was pointing more to the front. Was this so she could better access the body fluids?
Later still I discovered that the spider had finished her meal. I checked for bumblebee remains — in the flower stalk, on the ground, among the leaves. Nothing. Where did it go? A mystery.
I checked the lupine again today. The crab spider was still there. A moment later I stood transfixed as a fat bumblebee landed on the flowers, just petals away from the spider-in-hiding. Would she catch this one too?
Luckily for the bee she buzzed off to another stalk. As for the spider? She crawled out in full view, stretching out in the sun, legs poised, waiting …
Bumblebee Bombus spp.