Biologists sometimes field questions about a “huge scary bug” that
appeared in someone’s home or worse yet on their person. Most turn out
to be benign organisms that ended up in the wrong place. For me, the
most common questions come in July, when male dobsonflies emerge from
the Winooski River and often end up crashing into windows on the Saint
Michael’s College campus where I teach. The males have impressive
mandibles that look scary but are harmless to people.
Recently however, one of these questions did actually involve
something dangerous. One morning I received a call from a friend and
grade school teacher, who explained that she had managed to corral a
very large and intimidating centipede in a plastic container at her
school. I immediately emailed her a photograph of a house centipede,
fully expecting that to be the end of the discussion. House centipedes
commonly attract the attention of teachers and home owners. They
frequently get trapped in the sink at my children’s school, and I
discreetly liberate them so that they can eat real pests. However, in
this case, “house centipede” was not the correct answer. I asked if the
arthropod was slow moving and dark, thinking that perhaps she had found a
stranded hellgrammite. No, she said, it was fast. This was getting interesting!
My friend described a centipede that was black and orange at the
front, with a forked “tail” and yellow legs. Its most surprising feature
was its size, a full six inches long. At this point, I asked for a
photograph because the insect sounded like nothing I had encountered in
Vermont. From the photograph, I determined that it was most likely a
giant desert centipede (
Scolopendra heros). That settled the
first question, but left still many others unanswered. The school
principal wanted to know if the centipede was dangerous. Were there
likely to be more lurking about? Should he shut down the classroom? How
does a desert centipede end up in Vermont?
I reassured them that it was unlikely to find even one such centipede
in Vermont (and then less reassuringly suggested that, because one was
found, they keep their eyes open). I informed the state entomologist and
sent him photographs. I learned that desert centipedes give
particularly nasty bites. In some cases, they can cause renal failure
and even death. While death by centipede isn’t a common way to go, even
in the desert, this species was certainly due some respect.
I guessed that the centipede may have come up from the desert
southwest in packaging material, or perhaps through the pet trade. The
truth was more surprising. The school in question, like many Vermont schools, uses a children’s book called
Flat Stanley
to combine reading skills with art, geography, and just plain fun.
Because Stanley is flat, he can be mailed in an envelope, and many
children in schools across the world make their own Flat Stanleys and
send them to friends in other places. Their friends photograph Stanley
in interesting locations and return him along with local souvenirs. When
my son did this, we sent Stanley to Ireland, Cyprus, and Australia.
Stanley was sent by my friend’s student to an aunt in Texas, and she
mailed him back with Texas souvenirs. The package included a map of
Texas, a length of rope representing the horn span of a Texas longhorn, a
piece of prickly pear cactus, and a Ziploc® bag with a hole chewed in
the corner labeled, “DO NOT TOUCH – CENTIPEDE.” Why one sends a dangerous centipede (or any centipede) through the
mail is a mystery, but it certainly happened. While I can’t imagine that
this centipede would establish in Vermont even if dozens were sent, it
underscores the continuing need to educate the public about the dangers
of moving species to new locations.
On a positive note, the school has
added the now dead, preserved centipede to its invertebrate collection
for classroom use. I think that speaks very well for the school that the
students will learn valuable lessons from Flat Stanley’s travel
companion. Perhaps it will inspire some budding entomologists?
Declan McCabe teaches biology at
Saint Michael’s College. His work with student researchers on insect
communities in the Champlain Basin is funded by Vermont EPSCoR’s Grant
EPS-1101317 from the National Science Foundation. This article was
adapted from the Newsletter of the Vermont Entomological Society and most recently circulated by Northern Woodlands Magazine's outside story.
In
peaceful streams, aquatic macroinvertebrates such as crayfish,
stoneflies, and caddisflies travel over and under submerged rocks,
foraging for other invertebrates, leaves, and algae. When rain falls,
their world turns upside down. At first only the surface is disturbed,
but before long, runoff reaches the stream and increases its flow many
fold. Silt and sand blast every exposed rock surface. At peak flow,
boulders are propelled downstream by powerful currents.
