Hickory shuckworm larvae, Cydia caryana (Fitch), in pecan shucks, were killed by extended periods of freezing temperature. While storage at −7°C killed 88% of larvae after 32 days of exposure, −18°C killed 85% after only 1 day and 100% by 8 to 16 days of exposure. Larvae exposed to cold temperatures prior to −18°C exposure appeared to possess enhanced cold resistance but were still killed after 32 days of exposure. Survival of the ichneumonid parasite, Calliephialtes grapholithae (Cresson), which comprised 92% of the total of all parasites emerging from pecan shucks, was not detectably affected by exposure to cooling (3–5°C) for up to 5 wks. Thereafter, when emergence began to decrease, about half of the parasites in the extended cooling treatment were viable for at least 10 wks. Conversely, 3 other parasites Phanerotoma fasciata Provancher (Braconidae), Macrocentrus instabilis Muesebeck (Braconidae), and Lixophaga mediocris Aldrich (Tachinidae), comprised the remaining 8% of total parasite emergence and survival was severely affected by extended cooling (3–5°C).

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