New associations and host status: infestability of kiwifruit by Bactrocera dorsalis, Bactrocera cucurbitae, and Ceratitis capitata (Diptera: Tephritidae)

Authors: Follett, Peter; JAMIESON, LISA - New Zealand Institute Of Plant & Food Research; Hamilton, Lindsey; Wall, Marisa

Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/12/2018
Publication Date: 10/30/2018
Citation: Follett, P.A., Jamieson, L., Hamilton, L.J., Wall, M.M. 2018. New associations and host status: infestability of kiwifruit by Bactrocera dorsalis, Bactrocera cucurbitae, and Ceratitis capitata (Diptera: Tephritidae). Crop Protection Journal. 115:113-121. https://doi.org/10.1016/j.cropro.2018.09.007.
DOI: https://doi.org/10.1016/j.cropro.2018.09.007

Interpretive Summary: Studies were conducted to determine if kiwifruit is a host for three invasive tephritid fruit fly species that may enter New Zealand or other kiwifruit growing areas. Punctured and unpunctured fruits of green and gold kiwifruit were exposed to gravid female flies of Bactrocera dorsalis (Hendel) (oriental fruit fly), Bactrocera (Zeugodacus) cucurbitae (Coquillet) (melon fly), or Ceratitis capitata (Wiedemann) (Mediterranean fruit fly), in screen cages outdoors for 24h, and then held on sand in the laboratory for three weeks for pupal development and adult emergence. Overall, kiwifruit was a poor host for all three fruit flies. Puncturing fruit facilitated infestation. The average weight of puparia recovered from green and gold kiwifruit was roughly 50% of the weight of puparia recovered from papaya for all fruit fly species. Field infestation of kiwifruit suspended from papaya trees resulted in no infestation of green kiwifruit and very low infestation of gold kiwifruit by B.dorsalis, and no infestation in either cultivar by B.cucurbitae under natural conditions. This information will help inform decisions about quarantine restrictions and potential crop loss in the event of incursions of these fruit flies into New Zealand or other kiwifruit producing countries.

Technical Abstract: No-choice cage and field infestation studies were conducted to determine if the fruit of kiwifruit (Actinidia deliciosa, cv. ‘Hayward’ [green], and Actinidia chinensis, cv.‘Zesy002’ [gold]) is a host for three invasive tephritid fruit fly species that may enter New Zealand or other kiwifruit growing areas. For cage studies, punctured and unpunctured fruits of green and gold kiwifruit were exposed to gravid female flies of Bactrocera dorsalis (Hendel) (oriental fruit fly), Bactrocera (Zeugodacus) cucurbitae (Coquillet) (melon fly), or Ceratitis capitata (Wiedemann) (Mediterranean fruit fly), in screen cages outdoors for 24h, and then held on sand in the laboratory for three weeks for pupal development and adult emergence. Unpunctured green kiwifruit produced an average of 1.3, 0.0 and 48.8 puparia per kg of fruit for B.dorsalis, B.cucurbitae and C.capitata, respectively. Unpunctured gold kiwifruit produced an average of 54.7, 6.1 and 0.0 puparia per kg of fruit for B.dorsalis, B. cucurbitae and C.capitata, respectively. For comparison, unpunctured papaya, a preferred host for all three species, produced 492-795 puparia per kg of fruit, respectively, across all species. These results indicate that kiwifruit is a poor ovipositional host for B.dorsalis, B.cucurbitae and C.capitata. When kiwifruit were punctured to facilitate oviposition, the number of puparia per kg fruit increased significantly compared to unpunctured fruit for B.dorsalis, but not for B.cucurbitae or C.capitata, indicating that kiwifruit is a poor developmental host for these species. For all fruit fly species, the average weight of puparia recovered from green and gold kiwifruit was roughly 50% of the weight of puparia recovered from papaya. Field infestation of kiwifruit suspended from papaya trees resulted in no infestation of green kiwifruit and very low infestation of gold kiwifruit by B.dorsalis, and no infestation in either cultivar by B.cucurbitae under natural conditions. Overall, kiwifruit is a very poor potential host for B.dorsalis, B.cucurbitae and C.capitata. This information will help inform decisions about quarantine restrictions and potential crop loss in the event of incursions of these fruit flies into New Zealand or other kiwifruit producing countries.