Host plants of Melon Fly, Bactrocera cucurbitae(Coquillett)(Diptera:Tephritidae); and provisional list of suitable host plants of the Melon Fly, Bactrocera(Zeugodacus)cucurbitae(Coquillett)(Diptera:Tephritidae),Version 2.0

Authors: McQuate, Grant; Liquido, Nicanor; NAKAMICHI, KELLY - North Carolina State University

Submitted to: USDA CPHST Online Database
Publication Type: Literature Review
Publication Acceptance Date: 9/12/2016
Publication Date: 9/12/2016
Citation: Mcquate, G.T., Liquido, N.J., Nakamichi, K.A. 2016. Host plants of Melon Fly, Bactrocera cucurbitae(Coquillett)(Diptera:Tephritidae); and provisional list of suitable host plants of the Melon Fly, Bactrocera(Zeugodacus)cucurbitae(Coquillett)(Diptera:Tephritidae),Version 2.0. USDA CPHST Online Database. Available: https://coffhi.cphst.org/.

Interpretive Summary: The melon fly, the scientific name of which is Bactrocera cucurbitae, is thought to be native to India, but its distribution has spread throughout many countries in Oriental Asia, as well as into temperate Asia, into a number of Pacific Island nations, and into Africa. The documented introductions into countries outside its native distribution show that this species could establish in countries where it does not presently occur, particularly through the movement of infested fruit. As with other tephritid fruit fly species, establishment of the melon fly in new areas can have significant economic consequences, including damage and loss of food production, as well as requirements for implementation of costly quarantine treatments to permit export of commodities susceptible to infestation by the melon fly and inspection of susceptible imported commodities. In order to avoid these adverse economic consequences, one needs to prevent the entry, establishment and spread of the melon fly into a new habitat. To successfully achieve this, an accurate knowledge of the fly’s host plants is essential. Cognizant of this need, we prepared a worldwide summary of host plants of the melon fly. It is presented here both as an online searchable host plant database, as a provisional list of “suitable hosts” and as a provisional list of “undetermined hosts.” These documents provide a comprehensive documentation of host plants of the melon fly based on infestations reported from laboratory and/or field research, interceptions at ports of entry, and “listing only” associations, where a plant species is listed as a host, but no data is provided in support of that claim. Where citations to field data or lab data are provided, a succinct summary of the infestation data is provided along with the citation. Overall, a total of 136 plant taxa from 62 plant genera and 30 plant families are identified as “suitable hosts” of melon fly, based on reported field infestation data. The predominant family of host plants, as expected, is the family Cucurbitaceae, which includes gourds, melons, cucumbers, squashes and pumpkins. Within the family Cucurbitaceae, there are 56 plant taxa (41.2% of all host plant taxa) in which field infestation by the melon fly has been documented. The family with the 2nd highest number of documented infested plant taxa is the family Solanaceae, which includes the potato, tomatoes, eggplant, peppers and many garden ornamentals. Within the family Solanaceae, there are published field infestation data for 20 plant taxa (14.7% of plant taxa for which there is documented field infestation). Papers that list plants as hosts of melon fly based only on laboratory data, those that list plants as a host but do not report any field infestation data, and those that report interception data add an additional 137 host plant taxa, representing a total of 80 genera and 39 plant families, 20 of which are additional plant families beyond those for which there is field infestation data. These additional species must be considered “undetermined hosts” for which additional data are needed to document actual host status. The data presented herein on the host plants of the melon fly are designed to enable regulatory scientists and regulatory officials to assess the risk of melon fly being moved in fresh horticultural commodities, and to serve as a decision tool in the design and implementation of effective fruit fly detection, monitoring, suppression, and eradication programs of USDA and various state regulatory agencies.

Technical Abstract: The melon fly, Bactrocera cucurbitae (Coquillett), is a widespread, economically important tephritid fruit fly (Diptera: Tephritidae) species. Bactrocera cucurbitae infests fruits and vegetables of a number of different plant species, with many host plants in the plant family Cucurbitaceae, but with additional hosts scattered across many other plant families. Although thought to be native to India, its distribution has spread throughout many countries in Oriental Asia, into a number of Pacific Island nations, and into Africa. The documented introductions into countries outside its native distribution show that this species could establish in countries where it does not presently occur, particularly through the movement of infested fruit. As with other tephritid fruit fly species, establishment of B.cucurbitae can have significant economic consequences, including damage and loss of food production, as well as requirements for implementation of costly quarantine treatments to permit export of commodities susceptible to infestation by B.cucurbitae and inspection of susceptible imported commodities. In order to avoid these adverse economic consequences, one needs to prevent the entry, establishment and spread of B.cucurbitae into a new habitat. To successfully achieve this, an accurate knowledge of the fly’s host plants is essential. Cognizant of this need, we prepared a worldwide summary of host plants for B.cucurbitae. It is presented here both as an online searchable host plant database, as a provisional list of “suitable hosts” and as a provisional list of “undetermined hosts.” These documents provide a comprehensive documentation of host plants of the melon fly based on infestations reported from laboratory and/or field research, interceptions at ports of entry, and “listing only” associations, where a plant species is listed as a host, but no data is provided in support of that claim. Overall, 136 plant taxa from 62 plant genera and 30 plant families are identified as “suitable hosts” of B.cucurbitae, based on reported field infestation data. The predominant family, as expected, is Cucurbitaceae, with 56 plant taxa (41.2% of all host plant taxa) in which field infestation by B.cucurbitae has been documented. The family with the 2nd highest number of documented infested plant taxa is Solanaceae, for which there are published field infestation data for 20 plant taxa (14.7% of plant taxa for which there is documented field infestation). Papers that list plants as hosts of B.cucurbitae based only on laboratory data, those that list plants as a host but do not report any field infestation data, and those that report interception data add an additional 137 host plant taxa, representing a total of 80 genera and 39 plant families, 20 of which are additional plant families beyond those for which there is field infestation data. These additional species must be considered “undetermined hosts” for which additional data are needed to document actual host status. This paper is a comprehensive documentation of host plants of the melon fly based on recorded infestations in laboratory and/or field, interceptions at ports of entry, or “listing only” associations. Host records presented here will be used in vetting and developing the official USDA list of host plants of the melon fly, which will be published by APHIS as a federal order.