New discovery on pest fruit flies

Rome/Vienna — Research findings should reduce trade
barriers and boost pest control measures
Four of the world's most destructive agricultural pests are
actually one and the same fruit fly, according to the results
of a global research effort released today. The discovery
should lead to the easing of certain international trade
restrictions and also aid efforts to combat the ability of
these harmful insects to reproduce, experts said.
The so-called Oriental, Philippine, Invasive and Asian
Papaya fruit flies, the study shows, all belong to the same
biological species, Bactrocera dorsalis, which is causing
incalculable damage to horticultural industries and food
security across Asia, Africa, the Pacific and parts of South
America.
The international collaborative effort, involving close to 50
researchers from 20 countries, began in 2009 and was
coordinated by FAO and the International Atomic Energy
Agency (IAEA). It followed an integrative approach,
examining evidence across a range of disciplines.
The ability to precisely identify pests is central to pest
management, including quarantine measures or bans
applied to internationally traded food and agriculture
products such as fruit and vegetables.
Keeping exotic fruit flies out is a major concern for many
countries. The study's findings mean that trade restrictions
linked to the Oriental fruit fly should now fall away in cases
where the insect is present in both the importing and
exporting country, according to Jorge Hendrichs from the
Joint FAO/IAEA Division of Nuclear Techniques in Food and
Agriculture in Vienna.
"This outcome has major implications for global plant
biosecurity, especially for developing countries in Africa and
Asia," said the study's lead author, Mark Schutze, from the
Plant Biosecurity Cooperative Research Centre (PBCRC)
and the Queensland University of Technology (QUT).
"For example, the Invasive - now Oriental - fruit fly has
devastated African fruit production with crop losses
exceeding 80 percent and has led to widespread trade
restrictions with refusal of shipments of products into Asia,
Europe and Japan, and significant economic and social
impacts on farming communities," Schutze added.
Using sterilized males to mate with wild females
The findings of the study will also simplify techniques like
the use of sterilized males to prevent the growth of pest
populations.
A form of insect birth control, the sterile insect technique
involves releasing mass-bred male flies that have been
sterilized by low doses of radiation into infested areas,
where they mate with wild females. These do not produce
offspring and, as a result, the technique can suppress, if
applied systematically on an area-wide basis, populations
of wild flies in an environmentally friendly way. The FAO/
IAEA Agriculture and Biotechnology Laboratories have
demonstrated that the four fruit flies freely interbreed, which
means that instead of using males from the four supposedly
different species, mass-produced sterile Oriental fruit fly
males can now be used against all the different populations
of this major pest.
"Globally, accepting these four pests as a single species
will lead to reduced barriers to international trade, improved
pest management, facilitated transboundary international
cooperation, more effective quarantine measures, the wider
application of established post-harvest treatments,
improved fundamental research and, most importantly,
enhanced food security for some of the world's poorest
nations," Schutze said.
The findings of the FAO/IAEA coordinated study, published
in the journal Systematic Entomology means that the four,
previously considered distinct fruit-fly species, will now be
combined under the single name: Bactrocera dorsalis, the
Oriental fruit fly.