title: Developmental Acclimation of Drosophila suzukii (Diptera: Drosophilidae) and Its Effect on Diapause and Winter Stress Tolerance.
abstract: We investigated the influence of developmental conditions on adult morphology, reproductive arrest, and winter stress tolerance of the invasive pest of small fruit, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). Cooler rearing temperatures (15 °C) resulted in larger, darker "winter morph" (WM) adults than "summer morph" flies reared at optimal temperatures (25 °C). Abdominal pigmentation scores and body size measurements of laboratory-reared WMs were similar to those of D. suzukii females captured in late autumn in Geneva, NY. We evaluated reproductive diapause and cold hardiness in live-captured D. suzukii WMs as well as WMs reared in the laboratory from egg to adult under four developmental conditions: static cool temperatures (SWM; 15 °C, 12:12 h L:D), fluctuating temperatures (FWM; 20 °C L: 10 °C D, 12:12 h L:D), and static cool temperatures (15 °C, 12:12 h L:D) followed by posteclosion chilling (CWM; 10 °C) under short-day (SD; 12:12 h L:D) or long-day photoperiods (LD; 16:8 h L:D). Live-captured D. suzukii WMs and CWMs had longer preoviposition times than newly eclosed summer morph adults, indicating a reproductive diapause that was not observed in SWMs or FWMs. Additionally, recovery after acute freeze stress was not different between CWM-SD females and live captured WM females. More 7-d-old CWMs survived 0, -1, or - 3 °C freeze stress than summer morph adults, and more CWM-SD adults survived -3 °C freeze stress than CWM-LD adults. Survival after -3 °C freeze stress was significantly higher in diapausing, CWMs than nondiapausing SWMs and FWMs.
authors.affiliation: Department of Entomology, Cornell University, 630 W. North St., Geneva, NY 14456 (akw52@cornell.edu; gme1@cornell.edu), akw52@cornell.edu.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Wallingford
authors.affiliation: Department of Entomology, Cornell University, 630 W. North St., Geneva, NY 14456 (akw52@cornell.edu; gme1@cornell.edu).
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Loeb
mesh_terms: D000064:Acclimatization; D000818:Animals; D064666:Diapause, Insect; D004330:Drosophila / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D008297:Male; D012098:Reproduction; D012621:Seasons; D013312:Stress, Physiological
keywords: Drosophila suzukii; overwintering; reproductive diapause; stress tolerance; winter morph