Pollinating insects function significantly in structuring ecosystem as well as agricultural production. Among the variety of pollinators, Osmia cornifrons is one of the important pollinators in apple orchards. Unlike honey bees, O. cornifrons is able to pollinate at low temperature that facilitates its wide commercial use. The female O. cornifrons in nature lay their eggs to the interior of the bamboo reeds where they spend their larval and pupal stage throughout the summer and during fall they overwinter as adult. The adult bee emerges from the overwintering cocoon in the spring seasons. Since the complete synchrony with flowering period is critical, farmers collect and store the dormant state of O. cornifors in cold storage and expose them in due time to outdoor temperatures for their emergence, pollination activity can be performed. However, information on biological and ecological requirements for the emergence of overwintering adults are rarely reported. We carried out the experiments on temperature dependent adult emergence and constructed the emergence model based on developmental rate and distribution. Parameters were estimated from linear model and weibu