Resolution of Cryptic Species Complexes of Tephritid Pests to Overcome Constraints to SIT Application and International Trade


The objective of this CRP is to provide a clear description of biological characteristics of the species and the development of diagnostic tools for each species, resulting in facilitation of world trade and an enhancement of area-wide integrated pest management programmes that include SIT application.


Fruit flies are among the worst plant pests in agriculture, causing major losses in fruit and vegetable production, and are major targets of insecticide use in nearly all tropical, subtropical and some temperate countries worldwide. They are also of major economic importance because they result in the establishment of quarantines and the disruption of international agricultural trade. The Sterile Insect Technique (SIT) is increasingly applied operationally against the Mediterranean fruit fly; however, there are some important constraints to its use against other major fruit fly pests.

There are increasing demands from Member States in Africa, Asia and Latin America to resolve the uncertain taxonomic status of some key pest fruit fly species which exist as species complexes, i.e. fruit fly species that are morphologically similar and are not real separate species but only geographical variants. This uncertainty is having significant negative impacts on international trade and is resulting in the establishment of technically unjustified trade barriers to important commercial fruit and vegetable commodities. Also, some fruit fly populations grouped within the same species display different biological and genetic traits, which have important practical and economic implications for the effective use of the SIT. The resolution of some of the major cryptic species (i.e. insects whose specific status is questionable) complexes is therefore critical both for SIT application and to assist mainly subtropical and tropical Member States to overcome non-tariff trade barriers in order to export their fresh fruit and vegetable commodities to international high value markets.

The main targets of research are the Anastrepha fraterculus (Mexico, Central and South America), Bactrocera dorsalis (Asia, Africa and South America), Bactrocera cucurbitae (Asia and Pacific Ocean, Indian Ocean and Africa) and Ceratitis rosa (Africa and Indian Ocean) species complexes. Cryptic pest fly species within each complex are maintained in the laboratory and mating propensity, compatibility and competitiveness assessed under semi-natural conditions in field cages. In addition, the CRP seeks collaboration with researchers studying morphological, cytogenetic, molecular, and pheromone differences between species.


Seventeen participating countries: Argentina, Australia, Belgium, Brazil, China, Colombia, Czech Republic, France, Greece, Italy, Kenya, Malaysia, Mexico, New Zealand, Tanzania, Thailand, and USA.


  • The final proceedings of the CRP are available in ZooKeys 540 (2015) Special Issue on Resolution of Cryptic Species Complexes of Tephritid Pests to Enhance SIT Application and Facilitate International Trade.

Project Officer:

Jorge Hendrichs