In mid-August I joined Wayne Gall,
entomology curator for the Buffalo Museum of Science, on a tiger hunt along
Cattaraugus Creek.
No, we were not heavily armed -- we carried only
butterfly nets -- and to my best knowledge there are no threatening man-eaters
loose in the area. The tigers we sought were tiger beetles. Under a grant
from the New York Natural Heritage Program Dr. Gall and his Albany colleague,
Paul Novak, have been searching the state for rare species of this family.
Robert Graves and David Brzoska suggest that the
name 'tiger beetles' "probably refers to the predatory habits of these
insects, and also perhaps to the fact that many species are marked with
white stripes." I have a problem with the second part of their conjecture
as most tigers have black stripes on a predominately orange background.**
However, these beetles are indeed predators and they are at least as great
a threat to small insects as free-roaming tigers are to humans.
Fortunately these are only half-inch little devils.
Some
of the dozen or so species found in this area are brightly colored or marked
in striking patterns and they dash about on graceful long legs, but every
one of them has a mouth that would do justice to the Big Bad Wolf. Sickle-shaped
mandibles -- side-wise closing jaws -- are ready to grasp any prey foolish
enough to approach one of these efficient predators. And each sickle is
as long as the width of the beetle's head.
Adult tiger beetle (genus
Cicindela)
The tiger beetles we were looking for inhabit sandy
strands along the creek. These sandbars are generally located at the outside
of creek bends so they alternate from one side to the other. Thus we had
to wade back and forth across the creek to reach them and our wading that
day was made more hazardous by the heavy rain of the previous night. I
found that making headway against a swift current in chest deep water and
with my feet slipping on the flat shale bottom was indeed a challenge. On
one such crossing I suddenly found myself dislodged and underwater. When I
resurfaced, a wave knocked off my cap and glasses. As might be expected,
my frantic grabs retrieved only the $2.95 cap; those expensive glasses
today probably serve as a picture window for some caddis fly larvae.
Another challenge was finding the tiger beetles. We
searched
for over an hour before we saw any. The day was mostly cloudy but, when
the sun finally did appear, so too did the beetles. Dr. Gall found the
first few, but soon I learned the search image and I could see them standing
guard in the middle of open patches of sand.
Unfortunately, finding these little insects still
leaves the problem of catching them. Remember, beetles not only run; they
also fly. But Dr. Gall knew exactly what to do. When the beetles are threatened
they move with lightning speed, but usually in the same way each time.
Instead of running, they leap straight up and fly away. The trick is to
get the net over them and then to isolate them up in the webbing before
they find their way down and out around the rim. By the end of the day
Dr. Gall had captured and identified a dozen. (All but two retained for
museum specimens were then released.)
Remarkably, ten of the twelve turned out to be a
rare species seldom found here and Dr. Gall had found a still rarer species
-- first for the region since 1936 -- on an earlier trip to the same locale.***
To me this expedition was almost as exciting as a
real tiger hunt. Criss-crossing the creek provided some wild moments but
even more exhilarating was finding and capturing the rare beetles.
In the process we added to our understanding of the natural world around
us.
Who could ask for anything more?
* This quotation is taken from C. Barry Knisley and Tom D. Schultz, The Biology of Tiger Beetles and a Guide to the Species of the South Atlantic States (Martinsville, VA: Virginia Museum of Natural History, 1997). I recommend this resource not only for its interesting natural history sections but also because many of the species found on the Niagara Frontier are described in detail.
** Only rare mutant tigers have the orange replaced by white -- and not Siberian tigers as some people believe. Even in that case the stripes are still black against a white background.
*** The specific insects we collected were 10 Cicindela ancocisconensis T. W. Harris, and 2 bronzed tiger beetles, Cicindela repanda Dejean. The C. ancocisconensis -- we have found no common name for this rare species -- had been previously recorded less than a half dozen times in the state but Dr. Gall found them this year at five sites along Cattaraugus Creek in addition to where we located them that day. The rare tiger beetle that he collected earlier is the cobblestone tiger beetle, Cicindela marginipennis Dejean. One of only two previous state records was also from Zoar Valley, where we were collecting, in July 1936; the other was from downstate where Paul Novak believes it has been extirpated. All specimens from this region remain in the Buffalo Museum of Science entomology collection.
An excellent web site that provides a wide range of information about the Cicindelidae including keys is Gary Dunn's Tiger Beetle World. The photograph included with this essay is taken from that site with permission. A more general site with especially useful information for beginners who wish to collect beetles is Vr. Richard Bejsak-Colloredo-Mansfeld's Coleoptera website.