|Sunn pests and their control in the Near East. (FAO Plant Production and Protection Paper - 138) (1996)|
Cereal Development through Integrated Sunn Pest Management in West Asia and the Near East.
Afghanistan, Iran, Iraq, Jordan, Lebanon, Pakistan, the Syrian Arab Republic and Turkey.
Ministries of agriculture in participating countries.
Background and justification
Sunn pest is the common designation given to several species of pentatomids (shield bugs) that attack cereals (mainly wheat and barley) in the Near East. There are several genera and species involved, but the most important species responsible for damage of cereals in the Syrian Arab Republic, Iraq, Iran, Turkey, Afghanistan, Lebanon and the Commonwealth of Independent States (part of the former Union of Soviet Socialist Republics), Bulgaria and Romania is Eurygaster integriceps Heteroptera: Pentatomidae. Both nymphs and adults cause damage to plants and reduce yield by feeding on leaves, stems and grains (from green to mature). Apart from the direct reduction in yield, the insects also inject a toxin into the grains that adds a foul smell to the resulting flour and greatly reduces the baking quality of the dough. If as little as 3 percent of the grain is in such a condition, it is enough for the whole grain lot to be considered unacceptable for any baking purposes.
Only a small part of the insects life cycle takes place in the cereal fields. The adults spend the summer, autumn and winter in the mountains, in aestivation and hibernation, respectively. Overwintering adults begin to migrate to the fields in late March (spring) and the females lay eggs on the upper surface of cereal leaves and weeds. The newly hatched larvae moult five times and then become adults, some 50 days after oviposition. By this time, most of the overwintered adults are dead and the surviving adults start feeding on the grain at milky stage. This is the period when most damage occurs as the new adults feed intensively to build up adequate food reserves for the eight to nine months that they will spend in the mountains in diapause. As a result of this behaviour, fields close to the mountains suffer heavier damage than those on the plains.
Many climatic and biological factors influence sunn pest survival in the overwintering quarters and also in the cereal fields. For instance, harsh winters and egg parasites greatly reduce the populations that will move to the fields in spring.
Recent developments have made the sunn pest problems more serious. These include:
· growing of cereals in marginal lands (dry-farming closer to the mountains producing low yield that often do not warrant harvesting);
· overgrazing in the rangelands, thereby limiting natural vegetation that supports other pentatomids with common natural enemies (and causing a negative impact on biological diversity);
· elimination of refuges for egg parasites (coarse-barked trees);
· use of broad-spectrum insecticides for sunn pest control, usually by aerial spraying covering large areas.
All these factors combined threaten food security in the region and add much uncertainty to the traditional wheat-based agricultural systems.
Currently, sunn pest infestations, which could lead to 100 percent crop losses in the absence of control measures, are spread over thousands of hectares in affected areas. The current pesticide-based control measures are estimated to cost tens of millions of dollars annually (Table 35).
A joint FAO/ICARDA mission to the Syrian Arab Republic, Iran and Turkey in June 1992 to assess the sunn pest problem in the region revealed that sunn pest control is the responsibility solely of governments; farmers are not consulted. Governments are responsible for carrying out sunn pest surveys and forecasting, insecticide procurement, hiring of aircraft and field operations to distribute ground sprayers/insecticides and aerial insecticide spray operations. Since the mid-1980s, the area sprayed against sunn pest has increased, a situation which is the cause of much concern. The present insecticide-based strategies should be changed into a broader integrated pest management (IPM) programme that would include cultural practices (earlier-maturing varieties, crop rotation, more uniform dates of planting, double-stage harvesting) and conservation/augmentation of natural enemies. Eventually, this would transfer the responsibility for sunn pest control to the farmers.
Because of the prevailing attitude that the government is in charge and therefore that everything is under control, extension and research bodies are only marginally involved with sunn pest management. For instance, research activities on sunn pest were almost nil in the three countries visited, in stark contrast with those carried out some 30 to 40 years ago when most of the information available today was generated.
In the 1950s and 1960s, FAO played a very important role in establishing a regional information centre on sunn pest, organizing technical meetings, arranging expert visits to all affected countries, establishing an FAO committee on sunn pest and conducting regional training courses. The achievements made have lapsed since the introduction and resultant dependence on pesticides for sunn pest control, however. The presence of FAO and the participation of ICARDA are once more required to coordinate the actions necessary for the development of an IPM programme, which the FAO/ICARDA mission concluded was of top priority in order to guarantee the sustainability of wheat production in the area.
The projects main objective is to bridge the present gap between wheat and barley consumption and production in west Asia through the adoption and implementation of IPM practices directed towards cereal pest management in general and sunn pest management in particular.
Establishment of a regional network on sunn pest management. Outputs for such a network would be:
· the establishment of national and regional coordination committees on sunn pest management;
· the establishment of national and regional work plans on sunn pest management;
· regional reference centres designated;
· the establishment of a regional research and technology transfer subnetwork.
Enhancement a/information exchange. Outputs would be:
· a sunn pest newsletter published;
· literature on sunn pest and its natural enemies compiled and reviewed;
· a database on sunn pest and its management established and made available to participating countries;
· training manuals prepared.
IPM programme(s) identified and formulated. Outputs would be:
· surveys on sunn pest and natural enemies conducted;
· biological control investigated, tested and developed;
· cultural practices investigated, tested and developed;
· economic thresholds assessed and improved;
· selective pesticides screened and evaluated;
· IPM packages developed, assessed, improved and adopted by participating governments;
· land use improved.
Study and evaluation of economic impact of problems on production. Outputs would be:
· crop loss assessment methods evaluated, improved and harmonized;
· crop losses assessed;
· cost/benefit of currently applied control measures evaluated;
· strategies currently implemented by governments in sunn pest control assessed;
· effect on environment evaluated.
National programmes on sunn pest control strengthened. Outputs would be:
· national facilities and technical capabilities (research and extension) assessed;
· national programmes supported;
· staff trained.
Farmers trained and farmer involvement encouraged. Outputs would be:
· farmers associations for cereal development identified and, if necessary, established;
· farmers trained in identification of pests and their natural enemies;
· farmers trained in IPM of sunn pest.
Major donor inputs
International project personnel and consultants, contractual services, training provisions, travel, equipment and supplies.
Training and coordination of its research programme with the national and regional sunn pest control programmes.
Participating countries inputs
Launch national programmes, designate counterparts and provide facilities and transport.
TABLE 36 - Provisional project budget
Equipment and supplies