Jordan Carolina, de Carvalho Vanessa Rafaela, Horta André Ballerini, Lemos Manoel Victor Franco, Barbosa Rodrigues Jardel Diego, Passos José Raimundo de Souza, Domingues Maurício Magalhães, Zanuncio José Cola, Wilcken Carlos Frederico
Departamento de Proteção Vegetal, Universidade Estadual Paulista 'Júlio de Mesquita Filho' (UNESP), Faculdade de Ciências Agronômicas, Avenida Universitária, Botucatu, São Paulo, Brasil.
Departamento de Biologia Aplicada à Agropecuária, Universidade Estadual Paulista 'Júlio de Mesquita Filho' (UNESP), Jaboticabal, São Paulo, Brasilm.
Environ Entomol. 2025 Feb 19;54(1):101-108. doi: 10.1093/ee/nvae124.
The growing expansion of eucalyptus plantations in Brazil and the impact of exotic pests, such as Gonipterus platensis, demand effective, and sustainable biological control strategies. The aim of this study was to assess the pathogenicity of 10 Bacillus thuringiensis (Bt) isolates to neonate Gonipterus platensis larvae, commonly known as the eucalyptus weevil (Coleoptera: Curculionidae) with the specific focus of evaluating their potential to manage this pest while preserving its egg parasitoid, Anaphes nitens. To achieve this, the genomic DNA of the 10 Bt isolates was extracted using the thermal lysis method for molecular characterization of their Cry and Vip proteins. Neonate G. platensis larvae were subjected to bioassays with each isolate, at a concentration of 1 × 109 spores/ml, was applied on 10 larvae per replication (3 replications). The concentration and lethal time to kill 50% of the larvae were determined for the most effective isolates. The Bt isolates 107 and 178 isolates even at concentrations 10× lower than those recommended for commercial Bacillus thuringiensis var. tenebrionis (Btt) formulations against Coleoptera pests, achieved 100% mortality of G. platensis larvae. These isolates, with coleopteran-specific genes, caused high mortality of neonate Gonipterus platensis larvae. This indicates their potential for the biological control of this pest and maybe of other Coleoptera pests. Their use poses minimal risk to non-target organisms such as the egg parasitoid A. nitens and indicates a promising avenue for integrated pest management strategies with effective pest control while preserving the ecological balance.
巴西桉树种植园的不断扩张以及诸如桉象鼻虫（Gonipterus platensis）等外来害虫的影响，需要有效的可持续生物防治策略。本研究的目的是评估10株苏云金芽孢杆菌（Bt）分离株对桉象鼻虫（鞘翅目：象甲科）初孵幼虫的致病性，特别关注评估它们在保护其卵寄生蜂——尼特恩斯阿纳菲斯（Anaphes nitens）的同时管理这种害虫的潜力。为实现这一目标，采用热裂解方法提取了10株Bt分离株的基因组DNA，以对其Cry和Vip蛋白进行分子特征分析。将桉象鼻虫初孵幼虫与每株分离株进行生物测定，浓度为1×10⁹个孢子/毫升，每次重复处理10头幼虫（3次重复）。确定了最有效分离株杀死50%幼虫的浓度和致死时间。Bt分离株107和178即使在浓度比推荐用于防治鞘翅目害虫的商业苏云金芽孢杆菌变种tenebrionis（Btt）制剂低10倍的情况下，也能使桉象鼻虫幼虫死亡率达到100%。这些具有鞘翅目特异性基因的分离株，导致桉象鼻虫初孵幼虫的高死亡率。这表明它们在生物防治这种害虫以及可能的其他鞘翅目害虫方面具有潜力。它们的使用对诸如卵寄生蜂尼特恩斯阿纳菲斯等非靶标生物的风险最小，这为在保持生态平衡的同时进行有效的害虫防治的综合害虫管理策略指明了一条有前景的途径。
