Research Areas

Identification and characterisation of entomopathogenic viruses and microorganisms for their development as bioinsecticides.

Of the range of entomopathogenic viruses and microorganisms, we have focussed our attention on baculoviruses and the sporulating bacteria Bacillus thuringiensis, given their potential for development as commercial bioinsecticides. This area, therefore, is aimed at applied research; the general objective is to contribute favourably towards the development of new technologies, such as microbial bioinsecticides, in order to cut dependency on chemical insecticides for pest control. This research falls in line with the subject of Crop Protection which some members of the research group teach as part of Agricultural Engineer and Technical Engineer in Agriculture courses.

Baculoviruses

Baculoviruses form an integral part of ecosystems and perform a significant role in the regulation of natural insect populations. One of their chief characteristics resides in their specificity. To date, baculoviruses have only been isolated from invertebrates and, principally, insects. Infections by baculoviruses have been described in more than 700 species belonging to the orders Lepidoptera, Hymenoptera, Diptera, Coleoptera, and Trichoptera, and include many of the phytophagous species responsible for major crop damage in different parts of the world. In addition to being safe control agents, their infectivity being restricted to arthropods, baculoviruses do not generate waste in the environment and are compatible with other control agents, including predators and parasitoids. This has led to the WHO and FAO’s recommendation that the development of baculovirus-based bioinsecticides should be bolstered. The usefulness and effectiveness of baculoviruses for pest control in both agricultural crops and forest ecosystems have been widely demonstrated. There are currently more than thirty baculovirus-based bioinsecticides available on the market. The aim of our group is to identify and characterise new genotypes, or specific genes, which may prove useful in the design of new bioinsecticides.

Bacillus thuringiensis

Bacillus thuringiensis is the entomopathogenic microorganism most commonly used as a bioinsecticide at global level. Its toxic activity is based on the parasporal crystal which the bacteria synthesises during sporulation and which consists of proteins known as Cry proteins or δ-endotoxins. The crystal of most strains of B. thuringiensis contain between three and five δ-endotoxins, each with its own insecticidal specificity. The toxicity and insecticidal effectiveness of a bacterial strain is determined by the combination and relative proportions of δ-endotoxins present. More than 300 different toxic proteins have been identified in B. thuringiensis, making it a valuable, natural, pest-control resource. The genes which encode these insecticidal proteins have been used for the creation of transgenic plants with the insecticidal capacity of B. thuringiensis (known as Bt plants). Such new technology significantly enhances the potential of the practical application of this natural resource. The aim of our group is to characterise new Bt strains or new Cry genes with a wider spectrum of hosts or greater insecticidal potential for some species of insects considered pests of agricultural, forestry or medical-veterinary interest.