Genetic diversity, population structure and ecological niche modeling of Thyrinteina arnobia (Lepidoptera: Geometridae), a native Eucalyptus pest in Brazil.

Thyrinteina arnobia (Lepidoptera: Geometridae) is a native American species. Despite its historical importance as an insect pest in Eucalyptus plantations, more information is needed regarding the population diversity, demography, and climatic variables associated with its distribution in different regions of Brazil. We used a phylogeographic approach to infer the genetic diversity, genetic structure, and demographic parameters of T. arnobia. We also conducted an ecological niche modeling (ENM) to predict suitable areas for T. arnobia occurrence in Brazil and other countries worldwide. Although T. arnobia populations have low genetic diversity in Brazil, we identified mitochondrial haplogroups predominating in different Brazilian regions and high ФST and ФCT values in AMOVA, suggesting a low frequency of insect movement among these regions. These results indicate that outbreaks of T. arnobia in Eucalyptus areas in different regions of Brazil are associated with local or regional populations, with no significant contribution from long-distance dispersal from different regions or biomes, suggesting that pest management strategies would be implemented on a regional scale. In Brazil, the demographic and spatial expansion signals of T. arnobia seem to be associated with the history of geographical expansion of Eucalyptus plantations, a new sustainable host for this species. ENM indicated that isothermality and annual rainfall are critical climatic factors for the occurrence of T. arnobia in tropical and subtropical areas in the Americas. ENM also suggested that T. arnobia is a potential pest in Eucalyptus areas in all Brazilian territory and in regions from Africa, Asia, and Oceania.

Genetically engineered eucalyptus expressing pesticidal proteins from Bacillus thuringiensis for insect resistance: a risk assessment evaluation perspective.

Eucalyptus covers approximately 7.5 million hectares in Brazil and serves as the primary woody species cultivated for commercial purposes. However, native insects and invasive pests pose a significant threat to eucalyptus trees, resulting in substantial economic losses and reduced forest productivity. One of the primary lepidopteran pests affecting eucalyptus is Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae), commonly referred to as the brown looper caterpillar. To address this issue, FuturaGene, the biotech division of Suzano S.A., has developed an insect-resistant (IR) eucalyptus variety, which expresses Cry pesticidal proteins (Cry1Ab, Cry1Bb, and Cry2Aa), derived from Bacillus thuringiensis (Bt). Following extensive safety assessments, including field trials across various biomes in Brazil, the Brazilian National Technical Commission of Biosafety (CTNBio) recently approved the commercialization of IR eucalyptus. The biosafety assessments involved the analysis of molecular genomics, digestibility, thermostability, non-target organism exposure, degradability in the field, and effects on soil microbial communities and arthropod communities. In addition, in silico studies were conducted to evaluate allergenicity and toxicity. Results from both laboratory and field studies indicated that Bt eucalyptus is as safe as the conventional eucalyptus clone for humans, animals, and the environment, ensuring the secure use of this insect-resistant trait in wood production.

Safety Assessment of the CP4 EPSPS and NPTII Proteins in Eucalyptus.

Glyphosate herbicide treatment is essential to sustainable Eucalyptus plantation management in Brazil. Eucalyptus is highly sensitive to glyphosate, and Suzano/FuturaGene has genetically modified eucalyptus to tolerate glyphosate, with the aim of both protecting eucalyptus trees from glyphosate application damage and improving weed management. This study presents the biosafety results of the glyphosate-tolerant eucalyptus event 751K032, which expresses the selection marker neomycin phosphotransferase II (NPTII) enzyme and CP4-EPSPS, a glyphosate-tolerant variant of plant 5-enolpyruvyl-shikimate-3-phosphate synthase enzyme. The transgenic genetically modified (GM) event 751K032 behaved in the plantations like conventional non-transgenic eucalyptus clone, FGN-K, and had no effects on arthropods and soil microorganisms. The engineered NPTII and CP4 EPSPS proteins were heat-labile, readily digestible, and according to the bioinformatics analyses, unlikely to cause an allergenic or toxic reaction in humans or animals. This assessment of the biosafety of the glyphosate-tolerant eucalyptus event 751K032 concludes that it is safe to be used for wood production.

Two new species of Calonectria (Hypocreales, Nectriaceae) causing Eucalyptus leaf blight in Brazil.

In recent decades, commercial Eucalyptus plantations have expanded toward the warm and humid regions of northern and northeastern Brazil, where Calonectria leaf blight (CLB) has become the primary fungal leaf disease of this crop. CLB can be caused by different Calonectria species, and previous studies have indicated that Calonectria might have high species diversity in Brazil. During a disease survey conducted in three commercial plantations of Eucalyptus in northeastern Brazil, diseased leaves from Eucalyptus trees with typical symptoms of CLB were collected, and Calonectria fungi were isolated. Based on phylogenetic analyses of six gene regions (act, cmdA, his3, rpb2, tef1, and tub2) and morphological characteristics, two new species of Calonectria were identified. Five isolates were named as C.paragominensis sp. nov. and four were named as C.imperata sp. nov. The pathogenicity to Eucalyptus of both species was confirmed by fulfilling the Koch's postulates.

Danos provocados por coró-das-pastagens em plantas de eucalipto / Damages caused by coró-das-pastagens in eucalypt

Esta nota tem por objetivo relatar o ataque de larvas do coró-das-pastagens, Diloboderus abderus Sturm, 1826 (Coleoptera: Melolonthidae), em mudas de eucalipto híbrido (Eucalyptus grandis x Eucalyptus urophylla), na fazenda Bazana, município de Manoel Viana, Rio Grande do Sul. Essa praga se alimentou da casca das plantas na região do coleto, provocando “anelamento” das mudas. A mortalidade de mudas foi de 30 por cento em 40ha. Este é o primeiro registro dos danos desse inseto em plantas de eucalipto no Brasil.

This article aims to report the attack of larvae Diloboderus abderus Sturm, 1826 (Coleoptera: Melolonthidae) on seedlings of Eucalyptus hybrid ( Eucalyptus grandis x Eucalyptus urophylla), on the farm Bazana, in Manoel Viana, state of Rio Grande do Sul, Brazil. This pest consumed the bark of the ground, which caused the 'girdling' of seedlings. The mortality rate was 30 percent, in 40ha. No previous report was found in the literature regarding the occurrence of damages of Diloboderus abderus on Eucalyptus; thus, this is the first record of the pest on Eucalyptus in Brazil.