Evaluation of Genetically Modified eucalyptus expressing Bacillus thuringiensis proteins for Lepidoptera resistance

The primary woody species utilized in forest plantations in Brazil is Eucalyptus, which covers around 7.5 million hectares. Eucalyptus plantations face a significant threat from both native insects in the Americas and invasive pests, resulting in substantial economic losses and reduced forest productivity. One particular pest that affects eucalyptus is Thyrinteina arnobia (Lepidoptera: Geometridae), commonly known as the brown caterpillar. This caterpillar reproduces rapidly on various hosts and possesses voracious feeding behaviour and dispersal capabilities, making it prone to outbreaks, especially during drought periods. To combat this issue, FuturaGene, the biotech division of Suzano, has developed a genetically modified (GM) variety of eucalyptus that is resistant to insects (IR). This GM eucalyptus expresses three distinct pesticidal proteins (PP) derived from Bacillus thuringiensis (Bt), each with its unique mode of action and midgut binding sites. The leading GM event with the IR trait exhibited specific effectiveness against T. arnobia and Physocleora dukinfeldia (Lepidoptera: Geometridae). Field tests conducted in São Paulo and Mato Grosso do Sul, with artificial infestations, demonstrated 100% efficacy in controlling T. arnobia and P. dukinfeldia. This study offers valuable insights into the use of insect-resistant genetically modified eucalyptus in plantations, providing benefits such as early pest control before visible damage occurs in the field. Additionally, it helps optimize eucalyptus productivity and reduces the necessity for pesticide applications.