CAN WE LEARN FROM CICADA KILLERS?
watched from our back porch as a killer ascended to the top of a 20-foot
tree, carrying its defenseless victim. We knew what the outcome would
be. The target of the earlier attack would be buried alive in our backyard
or our neighbor's, while the perp left the scene unscathed, never to
be brought to justice. We could have stopped the flagrant act that was
clearly going to end unhappily for the victim, but no one wanted to
intervene and interrupt such a fascinating natural phenomenon.
watching a female cicada killer, one of the giant black-and-yellow solitary
wasps native to the United States, that had stung and paralyzed a large
cicada. Cicada killers do not live in nests like some wasps, but instead
each female digs a catacomb-like burrow underground, ready for development
of her young from egg to larva to cocoon-building pupa to emerging adult.
The process involves a female, which can be more than one and a half
inches long, finding a full-grown cicada (which may be almost as big
as she is), giving it a paralyzing sting, and then carrying it to the
burrow. They really should be called cicada paralyzers.
ultimately gets carried to the prepared tunnel and deposited in a side
pocket the cicada killer has dug, a sort of cave. The mother then deposits
an egg on the permanently helpless cicada. Through a scenario reminiscent
of the movie Alien, when the egg hatches, the larva enters the still-living
cicada's body, and then proceeds to get the nourishment it needs to
complete the development process. Skip the sugar-coated explanation:
the larva literally eats the cicada alive over a several day period.
After fattening up, the larva then turns into a fat pupa that spins
a cocoon and stays underground in its own little crypt for a year or
so. It emerges in the summer ready to go on a cicada quest if it's a
female, or to look for female cicada killers if it's a male. As is true
of many animal species, the males emerge from the ground and become
active earlier in the summer than females.
all this teenage cicada killer development can happen, the soon-to-be
mother faces the dilemma of finding a cicada. Step one is finding her
prey during the daytime, but when she does, she is an awesome airborne
attacker, being able to catch a cicada and bring it into submission
with a sting in mid-flight. Considering what it's like and how painful
it is when a honeybee or wasp stings creatures like ourselves that are
a thousand times larger, what is it like to be a defenseless cicada?
Would it be like our being jabbed with an 8-foot long, two-inch diameter
needle with an oil-drum full of venom? Instant paralysis is a plausible
killer's next problem is getting the cicada to the burrow, which after
the female's search may be a football field length away. Dragging it
over the ground is one approach. One approach is for the female to use
her back legs to hold the immobile cicada under her own body while using
her other four legs to walk. But when the burrow is a long distance
away, these enterprising insects have another strategy. Climb a tree
with the cicada quarry in tow, and then launch and glide in the direction
of the waiting cicada killer nursery. This is what the one we watched
was doing as it walked rapidly up the tree trunk to get a higher vantage
point and glide toward the burrow.
what do the males do while all of this cicada killing is going on? They,
too, have interesting behaviors to observe and probably one you are
more likely to see. Next week's column will explain why male cicada
killers will even attack humans, who really do not have to worry because
the males do not have stingers.
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