Tephritid fruit flies (Diptera: Tephritidae) are among the world’s worst pests of agriculture, being of major economic importance in nearly all tropical, subtropical and temperate countries. By laying their eggs directly into maturing fruit, where the maggots feed, these pest species cause enormous devastation to both food production and international trade despite often intensive insecticide applications. They are among the causes of poverty, malnutrition and poor production and trade in fresh horticultural commodities in large areas of tropical developing countries, impeding the development of lucrative and labour-intensive fruit and vegetable-based agro-industries in rural areas.
Some of these major pest fruit fly species occur within cryptic species complexes that include taxonomically described species that may actually be geographical variants of the same species. Conversely, some fruit fly populations grouped taxonomically within the same pest species display different biological and genetic traits, including reproductive isolation, suggesting that they are different species. This uncertain taxonomic status has important practical implications on the effective development and use of the sterile insect technique (SIT) against such pest complexes, where the species under mass-rearing is not the same as the population occurring in the target area. Uncertainty of taxonomic status can also result in the incorrect establishment of trade barriers for agricultural commodities that are hosts of pest tephritids.
The resolution of some of the taxonomic uncertainties that surround major cryptic species complexes is therefore critical both for integrated SIT application and for subtropical and tropical countries to overcome non-tariff trade barriers, enabling them to export their fresh fruit and vegetable commodities to international markets.
The following tree complexes and a suspected complex were identified to be of significant importance which needed to be resolved during the CRP to facilitate world agricultural trade and SIT programmes. They were:
• Anastrepha fraterculus (Americas)
• Bactrocera dorsalis (Africa, Asia and the Pacific)
• Ceratitis FAR complex (C. fasciventris, C. anonae, C. rosa) (Africa)
• Zeugodacus cucurbitae (suspected complex) (Africa, Asia and the Pacific).
Targeted, coordinated, multidisciplinary research was carried out to address, within an integrative taxonomic framework, the systematics and diagnostics of these cryptic species complexes of major tephritid pests of economic importance.
The accurate alignment of biological species with taxonomic names has led to the applied outcome of assisting FAO and IAEA Member States in overcoming technical constraints to the application of SIT against these major pest fruit flies and the facilitation of international agricultural trade between regions.
Researchers from Argentina, Australia, Belgium, Brazil, China, Colombia, the Czech Republic, France, Greece, Italy, Japan, Kenya, Malaysia, Mexico, New Zealand, Pakistan, Tanzania, Thailand and the USA participated in this CRP.
For more information, please see the CRP description:
https://www.iaea.org/projects/crp/d41023