The Numbers

Leptraps at Leptraps at
Tue May 29 11:01:08 EDT 2001

There has been a battle raging between Ron Gatrelle and some members of the Carolina Butterfly Society over collecting. 

For my 2 cents worth, I will try the numbers.

I am a very active Lepidopterists. I collect, prepare, lable, ID and place in my personal collection approxmately 2,800 specimens per year. I determined the number of specimens by the number of #2 insect pins I purchase each year. Also, it requires approimately 20 minutes from beginning to end to process a single specimen, or 933 hours, or 39 days. That is a lot of work and good deal of time. However, I will use 2,800 as an average for all Lepidopterists just to have a number.

There were approximately 3,100 members in the Lepidopterists Society, Southern Lepidopterists, Society, Ohio Lepidoterists, etc. I used the membership lists of these organizations and total all those who indicated they collect (There is some duplication as most Lepidopterists belong to some or all of these organizations.)

If 3,100 Lepidopterists collect and prepared on the average of 2,800 specimens per year, a total of 8,680,000. I have no idea how to determine the percentage of butterflies to moths. We will call the annual number 8.7 million.

I have been told or read that between May 1st and October 31, that there are over 9 billion butterflies and moths flying about every day in North America (USA & Canada). For the sake of argument (I am sure there will be some), 9 billion individual butterflies and moths fly every day. Lepidopterists collect 8.7 million. The percentage is a whooping 0.000966,  or less than one - one thousand of one percent.

The collecting argument is almost meaningless. 

Let's discuss collecting by autombile grill. My wife and I visited Cumberland Falls State Park in Kentucky this week end. Temparature have been well below normal and it was only 71 degrees at 2PM. As a result, Lepidoptera activity was rather minimal. However, as I walked through the parking lot to the falls I counted butterflies on the grills and bumpers of 32 cars. The average was 0.8 per vehicle. Now I realize that all this is hypothetical, but there are a 30 million cars in North America (USA & Canada), 24 million butterflies in one day. If all 30 million cars killed 10 butterflies per year, that is 300 million. If you use the daily 9 billion as proposed above, the percentage is 0.03. However, if you compute with 10 days of 9 billion, and cars kill 300 million the percentage is 0.0000033. Dam, that a lot of zeros, but wait, use the same formula, 10 days of 9 billion and collects kill 8.7 million, oops! that number is too small for my TI 5000 calculator to total.

There are not enough collectors to do the damage that is necessary to effect the overall populations of Lepidoptera. And most surprisingly, collectors visit the same places time and again, and the bugs are always there, until the habitat goes away. Once you look at the numbers, why argue?

I was never any good at math. How about it, anyone else want to try the number game for the overall population. 

Leroy C. Koehn
202 Redding Road
Georgetown, KY
"Let's get among them"


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