Monday, July 13, 2015

Wasps: Not Just Flying Agents of Pain

One of the things I encounter a lot when I talk to people about pollination is an intense fear of bees, and most especially of wasps. But wasps don't just sting you (and most won't sting without provocation); they also are pollinators. While on holiday at the lake, I captured a great series of a wasp worker hanging out on Achillea millefolium.

Unknown species of wasp on Achillea millefolium
Wasps are generally less hairy/fuzzy than bees, so they don't carry pollen as efficiently. But less efficient pollination != no pollination. Indeed, wasps are important pollinators in many ecosystems.

Another possible reason that wasps aren't such efficient pollinators of bees is that they don't (for the most part) rely solely on flowers for food. This individual actually may have inadvertently provided pollination services to the flower, but wasn't there collecting either nectar or pollen. She was dining on something else entirely:

A wasp eating something - note the ball of wax-yellow stuff
So I wondered what in the world she was eating. I looked from the front angle, hoping another angle might illuminate the matter:

Wasp eating something -- ball of stuff still unidentifiable
Nope, that was no help. Still a generally formless lump of gunk.

A quick glance around the environs, however, provided the answer:

Seems like a colour match for that wasp's meal
This dead grasshopper was on the stem of the flower where I found the wasp, and judging by the colour match and the big old hole in the dead grasshopper's abdomen, I suspect that the wasp found herself a rich source of protein and was taking advantage.

I suppose one animal's rather grisly find is another's feast.

Anyway, wasps will seek out other sources of protein (often to feed their young), including other insects, whereas bees generally don't. This reduced reliance on flowers may make them less likely to do the systematic flower-by-flower collection that also makes bees such suitable pollinators for flowers.

Wasps are actually an excellent biological control agent, as many of them have preferred prey which are pest insects on crops. I encourage them in my own garden because they're so efficient at getting rid of unwanted insects.

These oft-maligned insects are actually pretty awesome -- as long as you don't swat them or approach their nests late in the season.

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