General link sites:

Electronic Resources on Lepidoptera Huge list of lepidoptera links (can't beat this one)

The Butterfly Website - many good links and info

Lepidoptera links

Lepidoptera links (from the Utah Lep Society)

Lepidoptera links (from from TILS)

Societies:

The Lepidopterists Society - USA

Association for Tropical Lepidotera - USA

Sources of specimens for collectors:

The Insect Company - UK (Large selection, quality quite good)

Ianni Butterflies - USA (supplier for collectors. Also sell pins / mounting supplies) US F&W Licensed

Butterflies and Things - USA (supplier for collectors. Also sell pins / mounting supplies) US F&W Licensed

Insect World - USA (not a large selection, but changes every few months. )  US F&W Licensed

Ken Thorne - Canada (Large selection, worldwide representation)

Tropical Butterflies - Miguel Serrano at Tropical Butterflies Excellent supplier of superior quality material.  US F&W Licensed

INSECTS FROM FORMER USSR FOR COLLECTORS Web site - Ilya Osipov (Russia)

There are many more great suppliers, but unfortunately many don't have websites to link yet. More to come I'm sure. Some sites I have deliberately left out because I found CITES material being sold without permits. PLEASE don't do that. It is not only illegal no matter what country you are in, but it is highly unethical as well.
If you would like your site to appear here email us. There are many friendly collectors out there who love to exchange material. Part of the fun in collecting is the coorespondence with new people around the world...

Please note that if on review of your site we find that CITES certificates for listed specimens are not offered, or protected species are listed without appropriate permits, we will not list your website.

All of the above are CITES compliant and furnish necessary documents for listed species.

Please note: for collectors in the USA , to purchase dried material from a foriegn supplier you must declare it and be licensed by the US dept of Fish and Wildlife. Collectors in other countries do not have to worry about this but should be aware of any local regulations concerning importation of dried insects for scientific purposes.