![\"Anagyrus](\"http:\/\/newint.iita.org\/wp-content\/uploads\/2016\/11\/image_gallery-20.jpg\")
<\/a>Thail and\u2019s Department of Agriculture is expected to officially start the release of Anagyrus lopezi<\/em> (the wasp\u2019s scientific name) as a form of biological control in the country\u2019s northeastern province of Khon Kaen on Saturday (17 July), following two small scale releases to evaluate environmental impact.<\/p>\n\n\n\n \u201cCassava is an important crop for small-scale farmers in our country, so there\u2019s no time to lose in applying the fastest, most reliable solution available, said Amporn Winotai, who is a senior entomologist for Thail and\u2019s Department of Agriculture.<\/p>\n\n\n\n \u201cCassava is a crucial crop in Thail and, generating more than US$1 billion of income for farmers each year, and more again to industry,\u201d said Tin Maung Aye, a cassava agronomist with the International Center for Tropical Agriculture (CIAT by its Spanish acronym). \u201cReductions of that magnitude translate into hundreds of millions of dollars in economic losses, especially if the pest is allowed to spread further.\u201d<\/p>\n\n\n\n The pest is the cassava mealybug, known to scientists as Phenacoccus manihoti<\/em>. Originally from South America, it feeds only on cassava, sucking sap from the plants and causing them to shrivel. Also a South American native, cassava was carried by Portuguese traders to Africa and Asia, where it thrived in the absence of the insect pests that inhabit its home territory.<\/p>\n\n\n\n But eventually, the mealybug and others caught up with cassava, devastating crops first in sub-Saharan Africa and now in Southeast Asia. The spread of cassava mealybug to about 200,000 hectares has been confirmed in eastern and northeastern Thail and, where the pest is causing yield losses as high as 50 percent. Since the country\u2019s cassava industry generates more than US$1.5 billion of income each year\u2014 and the overall Thai cassava industry is worth US$ 3bn\u2014reductions of that magnitude could translate into hundreds of millions of dollars in economic losses, especially if the pest is allowed to spread further.<\/p>\n\n\n\n In mounting the emergency campaign, Thai scientists consulted with two organizations \u2013 the International Institute of Tropical Agriculture (IITA) branch in Benin and the Colombia-based CIAT, Both centers are supported by the Consultative Group on International Agricultural Research (CGIAR).<\/p>\n\n\n\n IITA, CIAT and various partner organizations curbed mealybug attacks on Africa\u2019s cassava crop during the 1980s through a highly successful biocontrol campaign, which staved off a major food security catastrophe, according to IITA entomologist Georg Goergen, who h and-carried a colony of the 500 wasps from Benin to Bangkok last year to start the testing and mass rearing.<\/p>\n\n\n\n Identifying the cassava mealybug species in Thail and was at first complicated, the Thai Department of Agriculture\u2019s Winotai said, by its resemblance to another closely related mealybug species, P. madeirensis<\/em>, which is probably also from South America but poses no threat to cassava.<\/p>\n\n\n\n Within a year after confirming the presence of the cassava mealybug, P. manihoti<\/em>, the Thai Department of Agriculture had arranged for importation of the pest\u2019s most effective natural enemy, following strict quarantine procedures, and then carried out controlled testing and mass multiplication ready for a possible release.<\/p>\n\n\n\n Early on, researchers discarded the option of containing the mealybug in Thail and with pesticides. \u201cApplying chemicals on such a large scale would be environmental v andalism,\u201d said Tony Bellotti, a CIAT entomologist, who has spent 35 years investigating cassava pests. \u201cSending in the wasps is a proven way to kill the cassava mealybugs quickly and effectively. Think of them as a kind of eco-friendly SWAT team.\u201d<\/p>\n\n\n\n Measuring less than 2 millimeters in length, the A. lopezi<\/em> wasp has already shown itself to be a formidable natural enemy of the cassava mealybug in South America and sub-Saharan Africa. Even when infestations are low, female wasps are able to detect and home-in on their prey, injecting their eggs into the mealybugs. The pest population is then gradually reduced, as the wasp larvae grow and as adult females feed on the host insect. The wasps pose no threat to humans, animals, or other insects.<\/p>\n\n\n\n The wasp proved so effective in sub-Saharan Africa that Hans Herren, the scientist who led the biocontrol effort there, was awarded the World Food Prize in 1995. The collaborative effort also earned IITA and CIAT the CGIAR\u2019s 1990 King Baudouin Award, which recognizes outst anding contributions to developing country agriculture. The economic benefits resulting from biocontrol of the cassava mealybug in Africa exceeded the cost of the research by a factor of at least 200.<\/p>\n\n\n\n CIAT scientists are investigating reports that that the cassava mealybug has already spread to Cambodia, Burma, Laos and Vietnam. Bellotti expects that it will soon reach other parts of Southeast Asia as well, including southern China, and eventually to Indonesia and the Philippines.<\/p>\n\n\n\n \u201cIt\u2019s going to be an international game of cat- and-mouse,\u201d he said. \u201cAs the cassava mealybug finds its way to new countries and regions, we can send in the wasps.\u201d In the long term, Bellotti explained, scientists will also need to develop cassava crops with genetic resistance to mealybugs as part of integrated pest management strategies. To be most effective, biocontrol must be combined with more resilient cassava varieties and better crop management.<\/p>\n\n\n\n “Cassava production in Southeast Asia has enjoyed an extended honeymoon, relatively free of major pest and disease outbreaks,\u201d Bellotti continued. \u201cBut now it\u2019s over. And the mealybug isn\u2019t the only cassava pest out there. Mites and whiteflies, for example, are also extremely damaging and there are some worrying diseases as well.\u201d<\/p>\n\n\n\n \u201cThail and\u2019s rapid response to stop the cassava mealybug plague shows international agricultural research at its best,\u201d said Ruben Echeverria, director general of CIAT. \u201cThis is why it\u2019s so important for developing countries to have strong research programs working closely with the international centers like CIAT and IITA.\u201d<\/p>\n\n\n\n ###<\/p>\n\n\n\n Pour plus d'informations, veuillez contacter :<\/p>\n\n\n\n Jeffrey Oliver, IITA, at o.jeffrey@cgiar.org<\/a><\/p>\n\n\n\n Michelle Geis, Burness Communications, at +301-280-5712 or mgeis@burnesscommunications.com<\/a><\/p>\n\n\n\n Neil Palmer, CIAT, at +57 2 445 0000 or n.palmer@cgiar.org<\/a><\/p>\n\n\n\n Le Institut International d'Agriculture Tropicale<\/strong> (IITA) is a nonprofit research-for-development organization that works with partners in Africa and beyond to tackle hunger and poverty by reducing producer and consumer risks, enhancing crop quality and productivity, and generating wealth from agriculture. www.iita.org<\/a><\/p>\n\n\n\n Le Centre international d'agriculture tropicale<\/strong> (CIAT) is a not-for-profit organization that conducts socially and environmentally progressive research aimed at reducing hunger and poverty and preserving natural resources in developing countries. www.ciat.cgiar.org<\/a><\/p>\n\n\n\n