Entomopathogenic nematodes (EPNs) can control pests due to mutualistic association with bacteria that reproduce and kill the host from septicemia, making the environment favourable for nematode development and reproduction. The objective of this study was to identify an EPN isolate collected in eucalyptus cultivation and to determine its pathogenicity with regard to Gonipterus platensis Marelli (Coleoptera: Curculionidae). Four steel-mesh traps with two seventh-instar Galleria mellonella larvae were buried 5 cm deep in the soil in a commercial Eucalyptus plantation. After 7 days, the traps were packed in plastic bags and transported to laboratory to isolate the EPNs using White traps. The obtained nematodes were multiplied in G. mellonella larvae and identified by sequencing their D2/D3 expansion of the 28S rDNA region by polymerase chain reaction (PCR) and specific primers for ITS regions. Steinernema diaprepesi was identified and inoculated into G. platensis pupae at doses of 500, 1000 and 5000 infective juveniles (IJs) to determine its pathogenicity to this pest. At 8 days after inoculation, the mortality rate of the G. platensis pupae was 80% with the lowest concentration and 100% with the others. The emergence of nematodes and the rapid degradation of G. platensis pupae were observed in those inoculated with IJs. The pathogenicity to the G. platensis pupae indicates potential for using this nematode in the integrated management of this insect.

The adaptation of native lepidopteran species to eucalyptus plantations reduces the productivity of this crop in Brazil. Oxydia vesulia Cramer (Lepidoptera: Geometridae) is a secondary pest, frequently reported in eucalyptus plantations with population outbreaks and economic damages. Methods of biological control of this pest may include the use of the exotic pupae endoparasitoid Tetrastichus howardi Olliff (Hymenoptera: Eulophidae), reported as efficient to controlling lepidopteran pests. The parasitism of O. vesulia caterpillars and pupae by T. howardi was evaluated under controlled conditions (25 ± 1 ºC, 60 ± 20% humidity and 12:12 h L:D). Each O. vesulia caterpillar or pupae was individually placed in a flat-bottom tube with 10 and 15 females of T. howardi for 48h, respectively. The parasitoids were removed after that period, the caterpillars were fed and the pupae were maintained until emergence of the parasitoid or formation of pupae and emergence of adults of this pest. The fourth-instar caterpillars of O. vesulia, after the parasitism period, were kept in pots with Eucalyptus urophylla leaves, changed daily until the end of the experiment. A total of 40% of the caterpillars died before the pre-pupae stage, 40% reached the pupae stage and died due to inadequate adult formation and 20% generated moths, but none adult parasitoid emerged from the caterpillars. All pupae of O. vesulia were parasitized and showed emergence of parasitoids. The parasitism of O. vesulia caterpillars and pupae by T. howardi shows the potential of this natural enemy for the integrated management of this defoliator pest in eucalyptus plantations.

The genus Sirex (Hymenoptera: Siricidae) consists of 29 species including the Sirex Woodwasp, Sirex noctilio, which is the main insect pest of pine plantations in the Southern Hemisphere including Brazil. In 2023, a species of Sirex similar to S. noctilio was discovered in Southeastern Brazil infesting pine plantations and causing tree mortality of up to 40%. We definitively identified this species as Sirex obesus based on both morphological characters and DNA barcodes. It is a species indigenous to the Southwestern United States and Northern and Central Mexico with little information available regarding its biology and control. This is the first record of S. obesus in Brazil and the first record of the species outside of North America. We document details about S. obesus occurrence in Brazil, describe preliminary damage caused in pine plantations and provide a partial list of natural enemies.

The area with ​​forest plantations in Brazil is one of the largest in the world, 9.93 million hectares with 75.8% (7.53 million ha) of eucalyptus plantations with a mean annual productivity of 38.9 m³/ha. These plantations are used to produce raw materials, mainly for the bioenergy, pulp and paper and laminate flooring sectors. Minas Gerais is the Brazilian state with the largest area of ​​eucalyptus plantations, more than 2 million hectares, followed by the Mato Grosso do Sul and São Paulo states (IBÁ, 2022 INDÚSTRIA BRASILEIRA DE ÁRVORES – IBÁ, 2022 [viewed 3 January 2023]. Annual report 2022 [online]. Brasília: IBÁ. Available from: https://www.iba.org/datafiles/publicacoes/relatorios/relatorio-anual-iba2022-compactado.pdf. In Portuguese. https://www.iba.org/datafiles/publicacoe... ). Insect pests, especially exotic ones, damage these plantations.

Entomopathogenic nematodes (EPNs) can control pests due to their mutual association with bacteria. The use of these biological control agents is increasing worldwide due to advances in research about its control efficiency, range of action and mass production. The identification of EPNs adapted to specific environmental and climatic conditions is important for sustainable pest suppression in integrated management (IPM) programs. The objective is to report, for the first time, the occurrence of the Steinernema diaprepesi in Brazil. Steel mesh traps with Galleria mellonella Linnaeus (Lepidoptera: Pyralidae) larvae were buried in red latosol cultivated with Eucalyptus. Infective juveniles (IJs) were isolated from dead larvae and multiplied in healthy ones of this host to confirm its pathogenicity and to start a laboratory population from the strain found in the field. The DNA of the IJs was extracted and amplified using PCR technique with the universal primers D2A and D3B. The detection of S. diaprepesi is the first report of this nematode in Brazil, increasing the knowledge about its distribution in the world and the diversity of EPNs that must be considered as agents of biological pest control in the country.