y working with nature, scientists plan to reduce a $42 million annual bill for chemical insecticides used in West Asia to control Sunn Pests.
        For now, governments have the choice between paying dearly for chemical control or facing equally crippling crop yield losses of 50-90% in wheat and 20-30% in barley. In addition, even an apparently small amount (2-3%) of grain damage to wheat by this serious pest can lead to rejection of an entire consignment for milling into flour. During feeding, the Sunn Pests inject chemicals into the grain that greatly reduce its baking quality once harvested and milled into flour.

specimens. With support from USAID Linkage Funds and from the Conservation, Food and Health Foundation, collections were made in Kazakstan, Kyrgyzstan, Syria, Turkey and Uzbekistan.
        The result is that entomologists from ICARDA, the University of Vermont and NARS (national agricultural research systems) in West and Central Asia and the Caucasus have now gathered several hundred different strains from which biological controls can be developed. In Syria they were assisted by colleagues from the University of Aleppo, and in Turkey by the University of Cukorova and the Plant Protection Research Institute of Adana. It adds up to the world's largest collection of these fungi, isolated specifically from Sunn Pest.
        However, it was also essential to establish that these microorganisms were really capable of performing the expected task--that of killing the adult Sunn Pest. Pathogenicity trials at ICARDA laid any fears to rest. Some of the fungal isolates were so highly pathogenic, they killed all of the treated insects in less than one week. The fungal spores lodge between the protective plates of the insects and then penetrate and develop within the insect, blocking vital life support systems.
        The next task for the team of scientists is to further evaluate the most promising of the isolates to select those which are likely to be of most use in the wide range of environmental conditions found across West and Central Asia. It is expected that many of those collected in the southern part of the region will be up to the task of killing the bugs under hot, dry conditions but may not perform as well in the much colder temperatures in the more northerly districts, and vice versa.
        When those isolates capable of having the widest application have been identified, they will be further tested in the laboratory and in the field for their effectiveness as biological controls. It is unclear at this stage just how farmers can use the fungal isolates. They could be applied to crops as sprays at critical times or it might be more efficient to introduce them into the overwintering areas favored by the Sunn Pests so that migration to cereal fields in spring is reduced.

        It is now planned to develop miniature insect-killing fungi as alternatives to chemical insecticides. These tiny microorganisms, which only attack insects and not the plants, will be used in concert with parasitoids, predators, cultural methods and other strategies in a comprehensive integrated pest management (IPM) program to reduce the impact of Sunn Pest damage regionwide.
        At mealtimes, wheat is the preferred choice of the Sunn Pest (Eurygaster integriceps Puton), but it will also feed on barley and rye, and occasionally on oats, sorghum and maize. It is a particularly serious pest in Cyprus, Jordan, Lebanon, Iran, Iraq, Palestine, Syria, and Turkey. A relative of the common stinkbug, it feeds on leaves, stems and grains by sucking fluids from them. Heavy attacks cause the stems to break, or empty 'whiteheads' to form containing no grain.
        Its table manners cause problems for flour millers and for farmers who lose a valuable market for their grain. As it feeds on soft young grains, the bug injects enzymes in its saliva into the grain. These enzymes digest the seed proteins and make feeding easier. However, these enzymes are then left in the harvested grain and are reactivated when water is added to flour to make dough.

        The enzymes destroy the gluten quality of the dough so that it is impossible to make bread from flour milled from grain with more than 2-3% damage from Sunn Pest.
        Whether the damage is to yield or to quality, it is a serious matter for farmers who dread the spring arrival of this pest and the devastation it can cause to their crops. The existing chemical control methods are expensive and undesirable from both environmental and consumer points of view. However, biological control as a component of IPM is a major focus of research at ICARDA into controlling both pests and diseases.
        Together with scientists from the University of Vermont, USA, a plan was designed to develop insect-killing fungi as alternatives to the costly chemicals. It was already known that tiny fungi infect Sunn Pests so the first move taken by the ICARDA/Vermont scientists was to find and isolate these potentially beneficial pathogens. Sunn Pest leaves the cereal fields after harvest and overwinters under fallen leaves in nearby foothills. This was where the researchers decided to concentrate their search for infected

        If the Central and West Asia regions are to have any hope of meeting the food needs of their population in the decades ahead, it is imperative that the present insecticide-based strategies are replaced with multi-dimensional IPM approaches. Insecticides must be replaced because they are expensive, frequently have a negative impact on the environment, and have questionable effectiveness because of the ability of insects to develop resistance to them.
        The insect-killing fungi have, however, developed over many years without the Sunn Pest being able to develop resistance to their fatal attacks. The next stage of trials will ensure that the most effective strains for a range of environments are identified to form the basis of future biological insecticides.
        The progress made so far with fungal pathogens is a clear indication that ICARDA, in cooperation with the University of Vermont, is on the cutting edge of this technology.


Drs Bruce L. Parker is Director of Entomology Research Laboratory, and Margaret Skinner is Assistant Professor at the University of Vermont, USA; Dr Mustapha El Bouhssini is a Senior Entomologist  at ICARDA.