Call edition 2012
A new edition of the Prize of the Belgian Development Cooperation has been launched. This call is open until March 31st, 2011. You can read in the regulations whether you comply with the criteria for participation.
Insects are a source of loss of agricultural productivity, particularly in developing countries. Insecticides cannot always be used because of product costs and secondary effects. The use of biocontrol methods is growing as a result, but these methods require the identification of the natural enemies. This is a problem because there is a shortage of systematicians trained in the modern techniques of biology.
In Vietnam, insects can cause 25% to 50% of agricultural production losses. Cases of resistance to insecticides are common, which means that dosages have to be increased, which in turn leads to increased negative secondary effects. However, a solution may lie in parasitism, and more specifically in the small round worms that belong to the group of Nematodes, basically divided into two families, the Steinernematidae and the Heterorhabditidae.
Entomopathogenic nematodes are widespread in the environment. They can survive in the soil a long time whilst they wait for a host insect. When the infecting larva has located the host insect, it moves towards it and penetrates the insect through one of its natural orifices (mouth, spiracles or anus). The larva then pours out its digestive content and with it a symbiotic bacteria. This bacteria multiplies rapidly and kills the insect within 48 hours. The nematode feeds on the liquefied tissues of the insect and the bacteria, reaches adulthood and multiplies to produce thousands of new infecting larvae.
This type of nematode is already being used in biocontrol and is sold by several producers. The difficulty lies in finding suitable species and strains that are capable of developing in the climatic conditions and soils of the targeted region.
Dr Long PHAN KE took 910 soil samples in 25 provinces of Vietnam between 1997 and 2001. Of these samples, 44 proved positive for the presence of entomopathogenic nematodes. Given that there are few morphological characteristics available with which to identify them, the author used several techniques, ranging from electronic microscopy to molecular biology, over crossbreeding. The use of sophisticated statistical methods enabled him to reconstruct the phylogeny of the species found and to place them in the current systematic framework. This important work puts Phan Ke among the world experts in this difficult field, which is as yet insufficiently studied
Report written by Prof. Dr T. Hance, Ecology and Biogeography Unit, Université Catholique de Louvain, Louvain-la-Neuve, Belgium