Global commodity trade and quarantine security: Biological vs regulatory hosts with special emphasis on host-plant relationship in the Tephritidae (Diptera)

Fruit flies belonging to genera Anastrepha, Bactrocera, Ceratitis, Dacus, and Rhagoletis impose enormous constraints on the diversification of agricultural production and expansion of global agricultural trade.  Their polyphagous feeding habits and persistent ecological adaptiveness rank them among the worst invasive pest species requiring vigilance for detection, effective monitoring, and regimented area-wide eradication.  Rigorous commodity quarantine treatments are currently enforced to prevent the worldwide spread of economically significant fruit flies.  In developing risk mitigation procedures to allow movement of commercial commodities, a particular fruit or vegetable is evaluated for its suitability as a host of a species or guild of species of quarantine-significant fruit flies.  The endpoint is valid determination of the regulatory status of a host commodity, or the host’s hazard as a pathway for the introduction of tephritid pests to a geographic area where they do not or are not known to occur.  A true biological host may be deemed a regulatory non-host due to “partial resistance or tolerance,” as conferred by “permissive or restrictive conditions” such as “stage of maturity and other physiological or physical conditions” rendering a natural host to become unsuitable (regulatory non-host) for normal development and reproduction of the associated tephritids.  The objectives of this presentation are:  (1) to compare the antithetical attributes of biological and regulatory hosts; and (2) to evaluate the use of host fruit suitability as the primary parameter in the development and implementation of an integrated risk mitigation measures and safeguards aimed to achieve acceptable quarantine security in legal distribution of fresh fruits and vegetables globally.