A method is presented for rapidly estimating the per cent of harvested alfalfa seeds damaged by the clover seed chalcid, Bruchophagus gibbus (Boh.). The method utilizes a technique of cementing a sample of seeds on paper to permit rapid microscopic examination. Three sampling experiments were conducted to determine the variance components associated with individual steps in the process of determining the level of chalcid infestation in a particular treatment. An optimum sampling scheme was developed from these components and from the cost of conducting the experiments. Two field samples per treatment were each sub-sampled twice. Two separate estimates of infestation were made on each subsample. This scheme permitted the best estimation of a treatment mean within 15% of the true mean, 95% of the time.