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Resolution of Cryptic Species Complexes of Tephritid Pests to Overcome Constraints to SIT Application and International Trade
Closed for proposals
Project Type
Project Code
D41023CRP
1729Approved Date
Status
Start Date
Expected End Date
Completed Date
23 July 2015Description
Tephritids are among the worst agricultural plant pests in agriculture and are of major economic importance in nearly all tropical, subtropical and temperate countries worldwide. These pest species cause enormous devastation to both food production and international trade, are key insect pests of horticultural crops and major targets of insecticide applications. They are among primary causes of poverty, malnutrition and poor production and trade in fresh horticultural commodities in large areas of tropical developing countries (Waterhouse 1993; Allwood and Leblanc 1996; Lomborg 2004), where climatic conditions are favourable for labour-intensive fruit and vegetable-based agroindustries.
The study of the biology and management of tephritids therefore requires significant international attention to overcome these hurdles and to assist Member States in developing and validating environment-friendly suppression systems to support viable fresh fruit and vegetable production and export industries. Such international attention has resulted in the successful development and validation of a Sterile Insect Technique (SIT) package for Mediterranean fruit fly. Demands for R&D support in that respect are diminishing due to successful integration into control programmes. There is now an urgent need to focus on the increasing demands from Member States in Africa, Asia and Latin America, to address the issue of major tephritid species complexes of economic importance. These are groups of species where the morphology is very similar or identical but biologically they are distinct species. Some major pest fruit fly species occur within complexes, and the uncertainty related to their questionable technical status results in major constraints to SIT application and international trade.
Objectives
To assist Member States in achieving sustainable fruit and vegetable production by overcoming constraints to SIT application and international trade through the resolution of cryptic species complexes of major tephritid pests.
Specific objectives
7.1 Identify and define the biological limits of closely related pest species within the South American fruit fly (A. fraterculus) complex.
7.2 Facilitate the taxonomic revision of the South American fruit fly (A. fraterculus) complex and develop corresponding diagnostic tools to distinguish these species.
7.3 Identify and redefine the biological limits and species status of five closely related species of economic importance within the Oriental fruit fly (B. dorsalis) complex.
7.4 Develop corresponding diagnostic tools to distinguish these species of the Oriental fruit fly (B. dorsalis) complex.
7.5 Determine the variability within the melon fly (B. cucurbitae) regarding geographic and/or host races among populations from Africa, Indian Ocean and Hawaii.
7.6 Identify and redefine the biological limits and species status of the members of the Ceratitis FAR complex.
7.7 Develop more robust species markers and identification tools for the members of the FAR complex.
Impact
The extensive and detailed studies of major pest fruit flies from Latin America (Anastrepha fraterculus complex), Africa and Asia/Pacific (Bactrocera dorsalis complex), Africa, Asia/Pacific and Indian Ocean (B. cucurbitae and Ceratitis FAR complex), conducted under this CRP have resulted in over 100 scientific publications and have provided a much better understanding of the biology, cytogenetics, ecology, morphology, genetics, and physiology of these different cryptic species complexes. They also led to formal decisions on the species status of some taxa within these complexes that has been accepted by FAO and the International Plant Protection Convention (which sets and harmonizes the international phytosanitary standards that govern international agricultural trade under WTO), and regional and national plant protection organizations, and that will benefit many countries through facilitation of international trade in horticultural commodities. The findings will also simplify and make more efficient SIT application against pest species of these complexes and facilitate international trade.
As an example, in response to CRP outputs resolving the B. dorsalis complex, a major pest complex from Asia, Africa and the Pacific, the Secretariat of the IPPC (International Plant Protection Convention) has responded by already hosting a market access and post-harvest treatment meeting (Okinawa, Japan, December 2014) to facilitate international trade for host commodities of the B. dorsalis complex.
Also a better understanding of the higher classification and placement of Zeugodacus as a separate genus will have implications for pest management and SIT in view of the differences in behaviour, attractants and mating systems.
A large collaborative network of scientists from different research fields working on pest fruit flies was established within and among regions which resulted in sharing methodologies, exploring new techniques, training and establishing standard approaches. This will facilitate future international cooperation for scientific exchange to solve applied agricultural pest problems.
Relevance
The CRP was essential to address and resolve the cryptic pest species issues identified by Member States and confirmed by the external consultants, particularly the lack of species limits in the various pest species comprising the A. fraterculus, B. dorsalis and Ceratitis FAR complexes of cryptic species. This is essential for species identification and is the basis for determining phytosanitary approaches and regulations. It also overcame the lack of reliable diagnostic tools and facilitated taxonomic revision for these pest species.
The results of the CRP are contributing significantly in assisting Member States in achieving sustainable fruit and vegetable production and in overcoming constraints to SIT application and international trade through the resolution of cryptic species complexes of major tephritid pests. In particular the resolution of the B. dorsalis complex have already been widely accepted by FAO (press release), IPPC (press release) and governments around the world, with significant trade implications, especially for horticultural trade between Africa and Asia and the Pacific.