How the Bumblebee Lost Her Buzz

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.

Caught

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.

Predator and prey

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.

Death among the flowers

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?

Manoeuvring her prey

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?

Too close for comfort

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 …

The watchful waiter


Goldenrod crab spider   Misumena vatia
Bumblebee   Bombus spp.

Full House

A range of appetites — lust to dust — happening here. The crab spider has snagged a fly for supper and a pair of blister beetles are busy making baby beetles. Meanwhile, almost out of sight, another beetle minding its own business.

Blister beetles (one of the longhorn beetles) are a staple of our roses. Judging by last summer each rose will soon house at least one.

Mating longhorn beetles with unidentified beetle

Although the beetles didn’t pay me any attention the crab spider was more alert and started to drag her meal off the petal.

Crab spider & fly and longhorn beetles

Crab sider and fly

The spider settled down after a few minutes and hauled her catch back up again.

Full house

Next time you pass a blossom take a second look — who’s living in your flowers?


Blister beetle   Lytta spp. ?
Goldenrod crab spider   Misumena vatia
Prickly wild rose   Rosa acicularis        (Provincial flower of Alberta)

 

Whose Bones?

As I followed a narrow trail not far from the red squirrel penthouse  a flash of white caught my eye.  A small skull, about 7 cm long (2.7 in), lay in the deep moss, a few vertebrae loose behind it. The two halves of the lower jaw, just centimetres away, were almost buried in the soft green.

The remains had lain there for some time, all flesh gone, bleached by air and wind and dappled sun.

Who died? I found no other remains but the skull was enough.

Its sharp teeth — including “Dracula” incisors — said carnivore. But who? The shape and size narrowed it down to a member of the weasel family. Even that is a big group — weasels, mink, otters, fishers, wolverines, skunks, badgers, martens and black-footed ferrets.

I know the predators who live in our woods so that eliminated some of the weasel clan. My book of skull drawings and a quick check online gave me the answer: a marten (aka pine marten aka American pine marten).

About the size of a house cat, martens are highly adapted to life in the forest. They’re fast, sleek and skilled at climbing. We once watched a life-and-death chase between a marten and a red squirrel in our yard. They were a blur of fur going up, down and around the spruce trees, leaping from branch to branch and tree to tree.

After several minutes the chase moved from our yard further into the woods. I’m not sure how it ended but it was one of those I-don’t-believe-what-I’m-seeing  moments.

Google “images pine marten” to see what they look like.


Marten   Martes americana
Red squirrel   Tamiasciuris hudsonicus