Scholarlink

<p><i>Spodoptera cosmioides</i> has become an important pest to soybean in the Americas since the incorporation of transgenic cultivars. The entomopathogenic nematode (EPN) <i>Heterorhabditis bacteriophora</i> establishes a symbiotic association with bacteria of the genus <i>Photorhabdus</i>, acting as insect control agent<i>.</i> The aim of this work was to determine the pathogenicity of <i>H. bacteriophora</i> and its symbiotic bacterium against <i>S. cosmioides</i> pupae. In the laboratory, insect pupae were placed in containers with sterile sand and then infective juveniles (IJs) of <i>H. bacteriophora</i> were applied to the surface. After 48&#xa0;h, pupa tissues were enzymatically digested and penetration of IJs into the insect haemocoel was observed in all treatments. In pot assays, pupal mortality of 13.3% and 26.7% was recorded 7&#xa0;days after the application of 100 and 1000 IJs, respectively. <i>Photorhabdus laumondii</i> (25, 250, 2500 or 25,000 CFUs) were injected into the haemocoel of pupae using a micro-syringe. After 96&#xa0;h, bioluminescence revealed bacterial growth in more than 70.0% of pupae. Field efficacy trials were conducted during three crop seasons. In entomological cages, emergence of insect adults was reduced by 41.8% with respect to the control treatment using a dose equivalent to 2.5 × 10<sup>9</sup><i>H. bacteriophora</i> IJs ha<sup>−1</sup>. The effects of EPN application did not differ significantly from those of the chemical treatment. We confirm the pathogenicity of <i>H. bacteriophora</i> and its symbiotic bacterium against <i>S. cosmioides</i> pupae. The application of EPN reduced the emergence of <i>S. cosmioides</i> adults; hence, this strategy can be used to decrease their populations in the field.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Biological control of Spodoptera cosmioides pupae by the entomopathogenic nematode Heterorhabditis bacteriophora in soybean crops

  • 期刊论文

  • 发表日期：

    2026年3月4日

查看全文
  • Federico Tuninetti,
  • Laureano S. Frizzo,
  • Federico F. Acosta,
  • Mauro S. Alisio,
  • Leopoldo Palma,
  • Eleodoro E. Del Valle

摘要

Spodoptera cosmioides has become an important pest to soybean in the Americas since the incorporation of transgenic cultivars. The entomopathogenic nematode (EPN) Heterorhabditis bacteriophora establishes a symbiotic association with bacteria of the genus Photorhabdus, acting as insect control agent. The aim of this work was to determine the pathogenicity of H. bacteriophora and its symbiotic bacterium against S. cosmioides pupae. In the laboratory, insect pupae were placed in containers with sterile sand and then infective juveniles (IJs) of H. bacteriophora were applied to the surface. After 48 h, pupa tissues were enzymatically digested and penetration of IJs into the insect haemocoel was observed in all treatments. In pot assays, pupal mortality of 13.3% and 26.7% was recorded 7 days after the application of 100 and 1000 IJs, respectively. Photorhabdus laumondii (25, 250, 2500 or 25,000 CFUs) were injected into the haemocoel of pupae using a micro-syringe. After 96 h, bioluminescence revealed bacterial growth in more than 70.0% of pupae. Field efficacy trials were conducted during three crop seasons. In entomological cages, emergence of insect adults was reduced by 41.8% with respect to the control treatment using a dose equivalent to 2.5 × 109H. bacteriophora IJs ha−1. The effects of EPN application did not differ significantly from those of the chemical treatment. We confirm the pathogenicity of H. bacteriophora and its symbiotic bacterium against S. cosmioides pupae. The application of EPN reduced the emergence of S. cosmioides adults; hence, this strategy can be used to decrease their populations in the field.