EU-funded researchers are tackling crop infestations with a targeted approach to biological pest control. They have used genetic analysis to identify the most effective natural enemies of aphids, mealybugs and other invasive insects. The results are feeding into better pest control approaches to limit crop damage - reducing losses to farmers and increasing food security.
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Invasive insect species have been the bane of farmers throughout history, but the problem has worsened in recent decades as climate change, globalisation and more intensive farming practices have enabled pests to spread far beyond their natural habitats.
By combining the expertise of leading international researchers, the EU-funded project IPRABIO has made important discoveries about the complex interaction between invasive crop pests and their natural predators in different environments worldwide.
Their work has led to ongoing research projects and applications in collaboration with industrial partners to provide effective natural pest control solutions that reduce or eliminate the need for environmentally harmful insecticides.
“IPRABIO has considerably changed the strategy of biocontrol programmes and redirected research to massively exploit molecular identification tools to increase efficiency and reliability,” says project coordinator Thibaut Malausa of the Institute National de la Recherche Agronomique in France. “In collaboration with industry, the research has led to two new biological products co-developed by IPRABIO participants that will be commercialised this year with potentially significant benefits for targeted pest control in Europe and elsewhere.”
Using molecular tools to study the genetic and physical makeup of a variety of pests and their predators, IPRABIO’s researchers generated an unprecedented amount of data on insects. The information led to the discovery of a number of new species and important insights for more targeted biological pest control strategies.
“Though biocontrol techniques have been used in the past, it is essential to correctly identify pests and their natural enemies in each habitat. Even if insects are relatively well-known, management methods are often jeopardised by the existence of species or strains that look like each other but behave very differently,” Malausa explains.
Incorrect identification of natural enemies can have disastrous results, with poorly implemented biocontrol strategies often causing more environmental problems than they solve.
One widely cited example is the disastrous introduction of cane toads to Australia in the 1930s. Intended to reduce sugar cane beetle populations, the toads, which are native to Latin America, instead spread disease and poisoned endemic species of mammals with catastrophic effects on local biodiversity.
Within IPRABIO, the researchers underscored the importance of fine-scale multi-criteria characterisation of species. For example, the team identified genetic divergence in populations of Pseudococcus viburni and Planococcus ficus, types of grape mealybugs that infest vineyards worldwide. The study provided insight that their natural enemies in a given country may not have the same effects if introduced elsewhere.
Conversely, DNA data have confirmed that a mealybug originating in South Africa Delottococcus aberiae would likely be effectively controlled in Europe through the introduction of a natural predator found in South Africa, a kind of tiny parasitoid wasp.
Overall, the IPRABIO work focused on nine invasive agricultural pests, primarily aphids and scale insects such as mealybugs, and their natural enemies, generating 16 scientific publications in peer-reviewed international journals and the development of software making it easier to use molecular tools in biocontrol strategies.
IPRABIO was funded through the Marie SkÅ‚odowska-Curie international research staff exchange scheme. Members of the IPRABIO team, including many early-stage researchers, have gone on to conduct continuing international collaborative research, launching the EU-funded Colbics, Aphiweb, Euclid and Biomodics initiatives. Some are working in national research projects in France and Chile.
“Agricultural pests trigger economic losses in large numbers of countries, but while these invasive species are international, most research and development programmes to study and manage them are not,” says Malausa. “We therefore brought together many national research projects sharing similar objectives that have typically been too isolated from each other.”