Entomopathogenic nematodes (EPNs) of the families Heterorhabditidae and Steinernematidae are used as biological control agents of several insect pests in lieu of synthetic pesticides. Using an insect-baiting technique, naturally occurring EPN isolates were collected from banana and rice fields in the municipality of Hagonoy, the Philippines. A total of 4 isolates were recovered from all the sites namely, HBP1, HBP2, HR3 and HR4. By combining morphometrical and ITS rDNA data, all the isolates were identified as Heterorhabditis indica. To initially assess their infectivity, virulence tests were conducted on the last instar larvae of the super worm, Zophobas morio Fabricius (Coleoptera: Tenebrionidae), the model insect. HR3 isolate had the highest percentage mortality (56%), followed by HBP1 and HBP2 (33%), which were comparable to the available nematode in the market, Heterorhabditis bacteriophora (44%), whereas the lowest was obtained in HR4 isolate (11%). This study accounted 4 more H. indica isolates in addition to pre-existing isolates in the country, expanding its habitat range and geographic distribution. This also provides baseline information on the potential biocontrol utilization of native EPNs against soil-dwelling insect pests of agricultural crops. Further investigations are required to assess their efficacy against several other insect pests of economic importance for the integrated pest management (IPM) programmes in the country.

中文翻译：

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从香蕉和稻田中分离出的天然菲律宾杂种印度and及其对超级蠕虫幼虫的毒力初步结果（Zophobas morio Fabricius鞘翅目：Tenebrionidae）

Heterorhabditidae和Steinernematidae科的昆虫病原线虫（EPNs）用作几种害虫的生物防治剂，代替了合成农药。使用昆虫诱饵技术，从菲律宾Hagonoy市的香蕉和稻田中收集了天然存在的EPN分离株。从所有位点，即HBP1，HBP2，HR3和HR4总共回收了4种分离株。通过形态计量学和ITS rDNA数据的结合，所有分离株均被鉴定为印度杂种人。为了初步评估它们的传染性，对超级蠕虫的最后一个幼虫，即模型昆虫Zophobas morio Fabricius（鞘翅目：Tenebrionidae）进行了毒力测试。HR3隔离株死亡率最高（56％），其次是HBP1和HBP2（33％），与市场上现有的线虫可比拟的细菌异形杆菌（44％）可比，而在HR4分离株中最低（11％）。这项研究除在该国已存在的分离株外，还对另外4种in稻分离株进行了分类，从而扩大了其栖息地范围和地理分布。这也提供了有关天然EPN对农业作物中土壤栖居害虫的潜在生物防治利用的基准信息。需要进行进一步调查，以评估其对该国其他综合性有害生物管理（IPM）计划具有重要经济意义的其他几种有害生物的功效。扩大其栖息地范围和地理分布。这也提供了有关天然EPN对农作物中土壤栖居的害虫的潜在生物防治利用的基准信息。需要进行进一步调查，以评估其对该国其他综合性有害生物管理（IPM）计划具有重要经济意义的其他几种有害生物的功效。扩大其栖息地范围和地理分布。这也提供了有关天然EPN对农业作物中土壤栖居害虫的潜在生物防治利用的基准信息。需要进行进一步的调查，以评估其对该国综合有害生物管理（IPM）计划具有重要经济意义的其他几种有害生物的功效。