Comparative cold tolerance in Ceratitis capitata and Zeugodacus (Bactrocera) cucurbitae (Diptera: Tephritidae)

Authors: Follett, Peter; Manoukis, Nicholas; Mackey, Bruce

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/15/2018
Publication Date: 7/31/2018
Citation: Follett, P.A., Manoukis, N., Mackey, B.E. 2018. Comparative cold tolerance in Ceratitis capitata and Zeugodacus (Bactrocera) cucurbitae (Diptera: Tephritidae). Journal of Economic Entomology. 111(6):2632-2636. https://doi.org/10.1093/jee/toy227.
DOI: https://doi.org/10.1093/jee/toy227

Interpretive Summary: Cold tolerance studies were conducted with the egg and larval stages of Mediterranean fruit fly and melon fly in Navel oranges to determine if quarantine cold treatments approved for Medfly might also be effective against melon fly. Navel orange is a good host for Medfly and a poor host for melon fly and therefore artificial infestation of fruit was required. Laboratory reared eggs and larvae were inserted in Navel oranges, placed in cold storage chambers at 1.5-2.0 oC for 2, 4, 6, 8, 10, 12, or 14 d, then removed and evaluated for egg hatch or larval survival. Medfly eggs were significantly more cold tolerant than melon fly eggs, whereas melon fly larvae were generally more cold tolerant than Medfly larvae. Medfly eggs and melon fly second instar larvae were the most cold tolerant life stages. Results suggest that cold treatment at <1.5 oC for a minimum of 14 days would be sufficient to achieve disinfestation of Medfly and melon fly.

Technical Abstract: Cold tolerance studies were conducted with the egg and larval stages of Mediterranean fruit fly, Ceratitis capitata (Wiedemann) and melon fly, Zeugodacus (Bactrocera) cucurbitae (Coquillett) in Navel oranges to determine if quarantine cold treatments approved for C.capitata might also be effective against Z.cucurbitae. Navel orange is a good host for C.capitata and a poor host for Z.cucurbitae and therefore artificial infestation of fruit was required. Laboratory reared eggs and larvae were inserted in the center of Navel oranges, placed in cold storage chambers at 1.5-2.0 oC for 2-14 d, then removed and evaluated for egg hatch or larval survival. C.capitata eggs were significantly more cold tolerant than Z.cucurbitae eggs, and Z.cucurbitae larvae were generally more cold tolerant than C.capitata larvae. C.capitata eggs and Z.cucurbitae second instar larvae were the most cold tolerant life stages and they were not significantly different from each other. Results suggest that cold treatment at <1.5 oC for a minimum of 14 days would be sufficient to achieve disinfestation of C.capitata and Z.cucurbitae.