The preoviposition period of R. pomonella (Walsh) varied from 5 to 11 days at constant and 6 to 15 days at variable rearing conditions. Its duration was influenced by the source of the adults, cultivars for oviposition, and rearing conditions: ca. 3 days longer for adults from infested Wealthy apples than for adults from infested Gravensteins, ca. 2 days longer when the apples for oviposition were late season cultivars, and ca. 1 day longer at variable than at constant rearing conditions. Estimates of the preoviposition period of adults in two unsprayed orchards were 14 and 21 days in 1979 and 16 days in both orchards in 1980, and were 7–14 days longer than that for adults at constant rearing conditions.
The oviposition periods of adults were 40–74 days at constant and 25–55 days at variable rearing conditions in 1979, and were influenced by the source of the adults, cultivars for oviposition, and the rearing conditions. Females from infested Gravensteins laid 339.2 and 180.7 eggs/female at constant and variable conditions and those from infested Wealthy 178.4 and 68.8 eggs/female at constant and variable conditions. Females also laid fewer eggs in Red Delicious apples than in Gravenstein, McIntosh, or Cortland apples.
The first spray for control of apple maggot in Nova Scotia can be applied at least 14 days after first emergence or first capture as the preoviposition period in natural (orchard) conditions exceeded the recommended time of 7–10 days.