Hi all
This has nothing to do with nosema, but the reference to nosema tolerant bees begins thus:

> Honeybees (Hymenoptera: Apidae), highly eusocial insects, first emerged ∼120∼130 million years ago, coinciding with the appearance of early angiosperms (Engel, 2001).

Engel does not say this in 2001, and especially not in later writing. He says:

> Honey bees are ubiquitous animals today, being important in both agricultural and natural ecosystems. The tribe consists of distinctive bees that perhaps arose and first diversified in the Early Oligocene, after the Eocene–Oligocene climatic transitions. However, stemgroup Apini have not yet been discovered and bees with the synapomorphies we use to circumscribe the group first appear in the Late Oligocene.

So, late Oligocene is more like 20-30 million years ago, not 120∼130. See: 

Engel, M. S. (2006). A giant honey bee from the middle Miocene of Japan (Hymenoptera: Apidae). American Museum Novitates, 2006(3504), 1-12.

As for bees in general, more recent work states:

> The oldest described fossil bee, Melittosphex burmensis, is from Burmese amber estimated to be 100–110 Myr (million years old]. Ohl & Engel also argue that it may in fact not be a bee, but a predatory wasp. 

Cardinal, S., and B. N. Danforth. 2013. Bees diversified in the age of eudicots. Proc. R Soc. B 280:20122686.

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html