102
 European bees. The relatively constant frequency for the Mspl variant M301

 in neotropical bees suggests that it is a neutral marker, incorporated as a result

 of west European introgression into the African population as it was becoming

 established and has been carried along as the bees have migrated north (Lobo

 & Kreiger 1992; Smith 1991).

 The release and spread of African bees has been disruptive to the

practice of beekeeping in the neotropics (Cantwell 1974; Goncalves, Stort &

De Jong 1991; Michener 1975; Roubik 1980, 1989; Spivak, Fletcher & Breed

1991; Taylor 1977; Winston, Taylor & Otis 1983). Migratory beekeeping and

commercial queen-rearing operations in the USA will be most severely impacted

if African bees are not excluded (Danka, Rinderer & Collins 1987; McDowell

1984). Identification of honey bees will be essential for the segregation of

African bees from the USA beekeeping industry, an integral component of the

intense agricultural system. The markers reported here will provide more

thorough and assurable information about the incidence of hybridization in the

neotropics, and will provide a means for following the progress of the African

bees in the USA (Hall 1990; Hall & Muralidharan 1989; Smith, Taylor & Brown

1989).