The life history in the Pacific Northwest has not been studied, but information from European literature should be appropriate for conditions and hosts here. C. florus overwinter as mature larvae on the consumed host larva. They pupate in spring, and adults are present when leafroller larvae are present. The female stings a fourth or fifth instar larva and then remains with the larva inside the webbed leaf shelter.
C. florus begins feeding. Up to 50 or more C. florus may be produced from a single host larva. The development time from egg to adult is about 15 days at 75°F. There appear to be only two generations of C. florus in the Pacific Northwest, but more could be produced if hosts of suitable size were available.
C. florus can be sampled by searching shelters of mature larvae. The first sign that C. florus might be present is the density of the webbing in the shelter. The webbing of a leafroller larva stung by C. florus is 3 to 4 times denser than a that of a normal leafroller larva. Even if adult C. florus have emerged, the pupal skins remain and are a good clue to the presence of this parasitoid.
Broad-spectrum insecticides are toxic to C. florus in Europe, but insect growth regulators and Bts are not. C. florus may not overwinter in high numbers because none of the leafrollers that are pests in orchards overwinter as late instar larvae, its preferred host size. Because C. florus is easily reared, it may be a candidate for augmentative release. This technique has been used in Europe with mixed results.