Cicada Killers
(This 1117th Buffalo Sunday News column was first
published on August 19, 2012.)
A few
days ago I received an interesting message from Dan Dolansky
of Olcott, whose family owns the Dolansky
and Sons Fruit Farm. I quote from that message here:
"Last week I was tending my onion and potato
field when I noticed dozens of large wasps flying around. I immediately thought
that they were European hornets and dreaded the thought of them keeping me from
our garden. I determined to find their source so that 'justifiable measures'
could be taken. Listening to warnings and lamentations from my wife Jessica, I
carefully searched for their paper nest.
"But then I noticed one of these large 1.5 to
2 inch beasts dropping to the ground. I looked carefully and saw the alleged
hornet with a bear-hugged cicada in its grasp. As she struggled to take the
prize overland I knew this could not be a hornet. My thoughts were affirmed
when I watched her drag the subdued insect down a hole on the side of a potato hill.
It wasn't long before I saw another wasp in midair similarly carrying a cicada.
And another. And another.
"In my years on the farm and my father Joe's
65 years of farming as well we had never before seen an eastern cicada killer.
I read about this remarkable creature and I urge you to tell your readers not
to fear this fearsome looking but gentle giant. These intimidating insects will
not sting unless you step on them. You can even hold them in your hand if
you're brave enough.
"Some internet sites
give advice about how to exterminate these wondrous wasps but I believe we
should understand and tolerate them. For example, I learned that a single
female cicada killer can cull 160 cicadas in a season.
I realize that many people enjoy the whining 'sound of summer' of the cicada
(as do I), but few realize the damage that these insects do to our elegant
deciduous trees in Western New York.
"Cicadas are notorious for cutting the bark of
twigs and laying hundreds of eggs at the injury causing the twig ends to die.
Also, their larvae and nymphs live underground sucking at the roots of those
same trees. Only the worst of our worst pesticides are effective against
cicadas so the cicada killer serves as a natural control and you can't get much
better than that.
"I guess my well-tended sandy soil garden of
onions and well-mounded potatoes were a welcoming mat for these interesting
insects. They will only be around for a little while so I will now enjoy my
large guests. I hope that Jessica will enjoy them as well."
Dan's delightful essay led me to do some further
research about these interesting insects. He's right that female cicada killers
are not at all aggressive. The males are more territorial, but their aggression
is fake: they don't even have stingers.
The female stinger is designed not to kill but to
paralyze the cicada, which is larger even than the wasp. The permanently
drugged insect is then carried to the already excavated burrow and pushed down
inside. These tunnels are quite lengthy and complex. They can be a yard or two
long with many side chambers in each of which one to three cicadas are stuffed.
Once a chamber is filled, a single egg is laid, an egg that will produce a male
wasp larva in a chamber with one cicada, an egg that will produce a female in a
chamber with two or three cicadas. Female cicada killers are larger than males
and thus require more sustenance.
The egg hatches in just two days and the larva that
emerges enjoys cicada meals for about two weeks. Then it constructs a cocoon in which it overwinters, to emerge as an adult wasp
the next summer.
These beneficial wasps can cause problems for
humans. The dirt they dig out of their tunnels can disfigure a lawn. Instead of
poisoning the wasp, it would be better to rake away the dirt pile.
I too enjoy those metallic summer buzzes of the
various cicada species but I now realize how destructive they can be and I join
Dan in speaking for these "gentle giant" cicada
killers.-- Gerry Rising