We propose a simple discrete-time host-parasitoid model to investigate the impact of external release of parasitoids upon the host-parasitoid interactions. The host population is regarded as a pest which is also subject to Allee effects and the parasitoid is used as a biological control agent. It is proved that the stocking of parasitoids can eventually eliminate the host population if the stocking is large. Due to Allee effects, there always exists a region of small pest population sizes below which the pest can be eliminated. The model may possess two interior steady states and sufficient conditions are derived for their local asymptotic stability.

biological control, Allee effects, local asymptotic stability.