butterfly diversity query

[Thomas Pape]

>>A question for the lepidopterologists out there:  how do the New World and Old
>>World (temperate and tropical) compare in terms of butterfly diversity
>>(family, genus & species)?  Is the New World richer than the Old, or are
>>they comparable?
>
>
>I saw Bob Robbins of the Smithsonian Institution give a talk on butterfly
>diversity a couple of years ago. He gave the following, approximate numbers:
>
>Region                 # butterfly species
>________               _____________________
>
>Nearctic                  750
>Neotropical              7500
>Afrotropical             3200
>Aust.-Orient.            4300
>Palearctic               1550
>
>
>        Obviously, the New World tropics are by far the richest for species.
>
>Brian

Interestingly, this picture changes slightly if one considers all of
Lepidoptera. Taking the data from tables in J.B. Heppner (Tropical
Lepidoptera 2 [suppl. 1]: 1-85), the Neotropical and Australian/Oriental
Regions are comparable:

Region                  # Lepidoptera species          species/Million sq.mi
_________               ______________________         _____________________

Nearctic                    11,532                         1,308
Neotropical                 46,313                         6,434
Afrotropical                19,528                         1,990
Aust.-Orient.               45,289                         6,140
Palearctic                  23,165                         1,234


Note: I have not taken into account the overlap in species between the
Oriental and Australian Regions, which could well increase the gap between
the Neotropical and Aust.-Orient Regions with some 10%. Still, the picture
remains about the same: Species richness is higher in the tropics (no big
surprise), while the Afrotropical Region is the 'odd man out' when compared
to the other tropical regions. A very similar picture is seen for other
speciose groups (e.g., Diptera, for which I have reliable figures, but
apparently also for plants).


Thomas Pape


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Thomas Pape
Department of Entomology
Swedish Museum of Natural History       Voice: +46 8666 4094
Box 50007                               Fax:   +46 8666 4099
S - 104 05 Stockholm, SWEDEN            e-mail: en-thomas at nrm.se

WWW URL:                          http://www.nrm.se/en/pape.html
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