07JULY ©FAO/F. COLOMBARI ©FAO/F. 2017 FAO TO PROTECT CHESTNUT FORESTS IN TURKEY USING CLASSICAL BIOLOGICAL CONTROL METHODS Chestnut (Castanea species) are tre- The Asian chestnut gall wasp (ACGW) can cause serious damage. However, es providing crucial resources for li- Dryocosmus kuriphilus Yasumatsu (Hy- protecting forest health from ACGW is velihoods in many parts of the world, menoptera: Cynipidae) is considered to possible using Integrated Pest Mana- with a wide range of economic, social be one of the most harmful insect pests gement (IPM) principles including clas- and environmental benefits. of chestnut varieties in the world and sical biological control methods. THE ASIAN CHESTNUT GALL WASP IN TURKEY During the first surveys, it was observed that 80 percent of branches of many trees had formed galls and the nut Chestnut has been a staple food in Turkey for millennia and production almost ceased in Gacik, Yalova. today the country is one of the biggest chestnut producers in the world. In all these regions, chestnut fruits are an CONTROL METHODS AGAINST THE ASIAN CHESTNUT GALL WASP important source of income for the rural population. Besides fruits, chestnut honey is another important product from these Pest control methods are required for the ACGW unlike other forests and chestnut trees are also used for wood production. gall wasps where gall-makers and host plants develop an equilibrium. However, pest management is challenging in ACGW has been reported in Turkey for the first time in 2014. Turkey due to ecological features and diversity, and abundance The entrance of the ACGW to Turkey appears to be through of tree species varying significantly within the country. plant material transportation. In 2014, the pest was observed in a few chestnut groves and in some 2000 ha forest areas in Several control methods have been used against the ACGW, Yalova and Bursa province of the Marmara Region. however, classical biological control methods have been FOOD CHAIN CRISIS | EMERGENCY PREVENTION SYSTEM | INFORMATION SHEETS FAO TO PROTECT CHESTNUT FORESTS IN TURKEY USING CLASSICAL BIOLOGICAL CONTROL METHODS KEYTHE ASIAN FACTS CHESTNUT GALL WASP (ACGW) ACGW IS COMMONLY RECOGNIZED AS THE MOST SERIOUS INSECT PEST OF CHESTNUT SPECIES WORLDWIDE ©FAO/F. COLOMBARI ©FAO/F. ATTACKS BY THE ACGW MAY STRONGLY AFFECT THE GROWTH the most successful. So far only the the most part of its life cycle parasitoid Torymus sinensis – as a within the galls where it is well OF CHESTNUT TREES, HAVING A biocontrol agent - has successfully protected from chemicals. NEGATIVE IMPACT ON FRUIT AND controlled its invasive populations. WOOD PRODUCTION FAO’S TECHNICAL ASSISTANCE IN Other measures applied against the CLASSICAL BIOLOGICAL CONTROL: A ACGW using IPM principles: SUCCESS STORY ONCE IN A NEW AREA, THE ACGW SUCCESSFULLY ESTABLISHES • Phytosanitary measures: ACGW In 2015, the General Directorate of BECAUSE OF ITS OVERWINTERING is on the quarantine list of EPPO Forestry of the Ministry of Forestry (European and Mediterranean and Water Affairs of the Republic of CAPACITY WHEREVER CHESTNUT Plant Protection Organization). Turkey requested FAO’s technical SPECIES ARE PRESENT assistance to manage the Asian • Early detection: young affected chestnut gall wasp population in the SEVERAL CONTROL METHODS plants must be immediately Marmara region. destroyed. HAVE BEEN USED AGAINST THE In late 2015, FAO started the project ACGW BUT SO FAR ONLY THE • Plant odors: ACGW follows “Control of Chestnut Gall Wasp in PARASITOID TORYMUS SINENSIS, kairomones pervading from Chestnut Forests of Turkey” with A BIOCONTROL AGENT, HAS branches and leaves and the the Directorate. In April 2016 and majority of these chemicals can be November 2016, FAO led two field SUCCESSFULLY CONTROLLED ITS produced synthetically and used missions to investigate the biology INVASIVE POPULATIONS as ACGW attractants with almost of the Asian chestnut gall wasp, no effect on the environment. This establishing a laboratory for rearing FAO ASSISTED IN ESTABLISHING is a recommended approach which and releasing the biological control is being tested. agent Torymus Sinensis imported from A LABORATORY FOR REARING Italy by the Directorate, and providing AND RELEASING THE BIOLOGICAL • Mechanical and physical control: theoretical and practical training CONTROL AGENT TORYMUS Positive results can be obtained activities for stakeholders (technical SINENSIS in chestnut nurseries by covering staff, foresters and chestnut growers) young plants with nets for two or on handling, rearing and introduction three months in summer, during and establishment of biological control FAO ASSISTED IN DEVELOPING the adult flight period, to avoid agent and other silvicultural practices PRACTICAL GUIDELINES oviposition in buds. to control the pest. DESCRIBING THE PROCESS AND • Cultural control: Pruning may FAO also provided technical guidance PROCEDURES TO MANAGE ASGW help reduce ACGW impact and to all stakeholders to identify the USING CLASSICAL BIOLOGICAL improve growth of weakened trees indigenous natural enemies, and CONTROL IN TURKEY but commercial growers cannot developed practical guidelines rely on this method because of the describing the process and procedures cost. for management of the Asian chestnut gall wasp using classical biological FAO FOREST HEALTH • Use of resistant varieties: This is control in Turkey. work in progress. E-MAIL In April 2017, the Government [email protected] • Chemical control: The use of Directorate of Forestry of Turkey chemicals may have serious announced the successful WEBSITES side-effects on the environment establishment of the natural enemy www.fao.org/food-chain-crisis and thus is not recommednded. of the Asian chestnut gall wasp in the Furthermore, the ADGW spends Yalova region. © FAO, 2017 - I7510EN/1/06.17 © FAO, FCC-EMPRES | INFORMATION SHEETS | 07 | JULY | 2017.