60
in northern Mexico may be a consequence of small sample size, but more likely

reflects the small east European contribution to the feral population in this area.

 Frequencies for the Mspl variant group M300 in the USA (18%) and in

northern Mexico, prior to the arrival of African bees (64% the highest of all

the New World populations examined), are consistent with the history of the

importation of west European bees in North America, their limited commercial

use, and persistence as feral colonies. The presence of the west European

variant M301 is also in agreement with MDH allozyme frequencies in USA bees

(which indicate A. m. mellifera nuclear genes persist in feral colonies; Sheppard

1988, 1989). West European mitochondrial DNA was detected at frequencies

of 7% in USA managed colonies and 64% in feral colonies in northern Mexico

prior to the arrival of African bees (Hall & Smith 1991) and was detected in

21% of 422 feral colonies in the south-central and southeastern USA (Schiff

& Sheppard 1993). Thus, bees of west European ancestry continue to

contribute to the honey bee gene pool in feral colonies of North America.

 Ddel variant group D300 was detected at the highest frequency in USA

bees, consistent with the detection of variants in this group in each of the three

European races examined, and at the highest frequency in A. m. ligustica.

Ddel variants D401 and D404 were found in two separate USA colonies; D401

was found in a feral colony near Tucson, Arizona, and D404 was found in a

managed colony in Kansas. This finding was noteworthy because the D400

variant group was found at high frequency in South African bees. D401 was