Microctonus aethiops(Nees), a European braconid parasitoid of adult alfalfa weevils,Hypera postica(Gyllenhall), was first established in the eastern United States in 1961 (Coles and Puttler 1963). Brunson and Coles (1968) listed release localities ofM. aethiopsthrough 1967, and it has been released in many other localities in the East and Midwest since then. Day et al. (1971) described the distribution ofM. aethiopsin the eastern United States and gave the dates of first recovery in many eastern states. However, to my knowledge it is not known how farM. aethiopshas dispersed from an initial release site where a known number of parasitoids was released.