[NHCOLL-L:874] resolving the issue of "World's Largest Insect"

[Doug Yanega]

Hi. I've been asked to help give as conclusive an answer to this question
("largest", not "longest") as is possible, for Dave Williams, who is
writing a new version of the entry in the University of Florida Book of
Insect Records (linked on my homepage). At this point, he's done most of
the groundwork, and all that may be needed now is (1) legitimate
measurements that are near or in excess of the measurements he has recorded
thus far, and (2) cases where both the linear measurements AND dry weight
of the same specimen are known. There may be folks here he has not
contacted yet, so I'll make one last request for data on his behalf before
he finalizes the article. To wit:

There are only five contenders, and the maximum reliable lengths recorded
for them (males, from abdominal apex to tip of horns/jaws) are:

Titanus giganteus: 16.7 cm
Megasoma elephas: 13.7 cm
Megasoma actaeon: 13.0 cm
Goliathus goliatus: 11 cm
Deinacrida heteracantha (Giant Weta): 8.5 cm

Basically if anyone has specimens of these species which are near or above
these limits, please contact Dave (dwilliam at corp.stjoe.org); BUT note that
linear measurement alone is NOT sufficient grounds for determining the
"winner", and it is especially important to get length, width and thickness
measures *correlated with weight* to help make an accurate decision (some
collectors distend their specimens to make them appear up to about 15%
longer, but having width and thickness measures included can rule out such
spurious records). At present, for example, the heaviest insect listed
above is the Weta, which is the shortest, but the data point (71 grams) is
for a gravid female live weight, and unfair in comparison to the males of
the beetles, for whom only dry weights are available (a maximum around 27
grams, with one live weight estimate for a Goliathus of 35 grams). It has
been a major problem for Dave to get enough data points for the other
species to be able to accurately extrapolate the dry weight of a specimen
of a given length and width, or correlate wet to dry weight, and evidently
none of the individual specimens listed above have actually been weighed!
Ultimately, then, Dave will need a bit more data than just a head-to-tail
length.
I think you can see the problem with giving a definitive answer to this
question.

Dave is NOT looking for nominations for alternative candidate species,
unless there's something undescribed that he needs to know about and it
clearly beats the total bulk of the other candidates (e.g., there were tall
tales from some canopy foggers that they had found a one-kilo katydid in
Peru; this has never been confirmed with an actual specimen, and even 100
grams would make it the heaviest insect known, so it's unlikely to be
true).

Again, PLEASE send any data to Dave (dwilliam at corp.stjoe.org) and NOT to
me! I'm only posting here to solicit help for him.

Thanks,


Doug Yanega        Dept. of Entomology         Entomology Research Museum
Univ. of California - Riverside, Riverside, CA 92521
phone: (909) 787-4315 (standard disclaimer: opinions are mine, not UCR's)
           http://entmuseum9.ucr.edu/staff/yanega.html
  "There are some enterprises in which a careful disorderliness
        is the true method" - Herman Melville, Moby Dick, Chap. 82