Plan A or Plan B (ee)?!?
Walking through the early successional habitats at Stephen J. Young Marsh (e.g. grassland, shrubland, young forest) , I fixate on any big (relatively speaking), bold, or brightly colored creature sporting patterns of yellow and black. No need to worry about me (maybe); I’m conducting the latest round of nonlethal bumble bee surveys on Missisquoi National Wildlife Refuge, a project that will provide much-needed pollinator data for future habitat management decisions.
During the last few years, the experience of conducting bumble bee surveys has humbled me. Knowing all too well that busily buzzing fly-bys are challenging to catch with a net, I look for bumbles feeding on flowers first. With a swing of a net, I capture the first bumble bee of the day (yeah!). Although the bee appears perfectly normal, the fact that it’s quiet, motionless, and remains on the flower, tells a different story. Upon closer examination, I realize that I’ve stumbled upon a grisly scene. This bumble bee isn’t buzzing anywhere; it’s gone to that big celestial flower patch in the sky!
Taking one last look, I’m startled to find eight tiny eyes observing me. That’s when I realized this was no ordinary death—this was premeditated murder and the suspect had returned to the scene of the crime! Looking into the eyes of the killer, I was understandably upset, but there was no malice or ill intent; this goldenrod crab spider was merely feeding itself, just as Mother Nature intended.
I must admit that goldenrod crab spiders are amazing creatures in their own right. Tiny (0.20- 0.39 inches) predators, they can skip sideways like their namesake and change their body color. The change from white to yellow requires the production of yellow pigment, taking around 10-15 days to complete; turning back to white takes less time (around 6 days) since the pigment is easily excreted. Their complex eye arrangement allows them to view flowers and their body simultaneously, to better match the color of their surroundings.
Although the bumble had a violent death, it probably never knew what hit it. As a sit-and-wait predator, goldenrod crab spiders hide in plain sight. They quickly grab prey with their legs, immobilize it with venom, inject it with enzymes to liquefy its insides, then suck the liquid out, like a smoothie for dinner. With fall flowers in bloom, and bumble bees flying in force, not even a bumble bee enthusiast, like me, can blame it. After all, no selfrespecting predator would continue with Plan A (eating a variety of small insects like flies, thrips, moths) when it could switch to Plan B (ee)!
by Judy Sefchick, Wildlife Biologist, Missisquoi NWR