Submitted to: Annual Review Of Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2007
Publication Date: 1/25/2008
Citation: Aluja, M., Mangan, R.L. 2008. Fruit fly (Diptera: Tephritidae) host status determination: Critical conceptual and methodological considerations. Annual Review Of Entomology. 53:449-472. Interpretive Summary: Fruit flies are one of the most important family of pests that attack fresh commodities and invoke quarantines to trade. Although there are several hundred described species in the fruit fly family Tephritidae, fewer than 1% are widespread pests on commercial fruit and most species are restricted to a few closely related host plant species. Knowing the host plant range of pest species of fruit flies is essential to programs that address methods of preventing introductions of these species into non-infested areas. Erroneous reports of host status needlessly restrict trade and the availability and cost of fresh fruits due to quarantine restrictions and costs of preventative treatments. In this paper, we review the evolutionary and ecological factors that affect host status and we propose research standards for reviewing past literature and experimental methods to test host status. We propose a flow diagram for carrying out the needed research and for establishing context to review past literature. We also review regulatory standards and propose methods to integrate degree of host usage by pests into a systems approach which integrates the known biology of the pests into a system that minimizes the probability of establishment of pests while allowing trade in fresh commodities.
Technical Abstract: Despite the fact that fruit fly host status determination/designation lies at the heart of strategic decisions on national and international trade of fruit and vegetables, all attempts so far to clearly define host plant status have been contentious and as a result, long standing disputes between commercial partners throughout the world have lingered over decades. Part of the problem is that too little effort has been devoted to understanding the underlying mechanisms involved in host plant use by fruit flies and that instead economic and political interests usually prevail. To untangle the knot, here we review the most important evolutionary, biological, ecological, physiological and behavioral aspects that drive host use by fruit flies and then construct a flow diagram rooted in these fundamentals outlining a series of steps and definitions to determine if a particular fruit or vegetable (and cultivars thereof) is a natural host or alternatively, if it should be considered a conditional (potential, artificial) host or a non host. Along the way, we incorporate risk analysis considerations and propose that the underlying complexity determining host plant utilization by fruit flies requires a flexible Systems Approach capable of realistically dealing with fly/host/environmental/geographic variability on a case by case basis.