BUSCADOR RECOLECTA

Digital.CSIC. Repositorio Institucional del CSIC

oai:digital.csic.es:10261/264100

The data were generated by the authors in independent experiments, all performed in the same conditions and installations. All the experiments were performed twice and the data corresponding with trials 1 and 2 of the same set was compared to allow combination in the statistical analysis. Each trial was performed with new and fresh nematodes and insects, Entomopathogenic nematodes (EPN) are excellent biocontrol agents against various insect pests. Novel biotechnological approaches can enhance their utility against insects above-ground, opening a new venue for selecting superior EPN against certain insects. We hypothesize that different populations of the same species but from different origins (habitat, ecoregion) will differ in their virulence. This study aimed to evaluate the virulence of various EPN populations against two pests of worldwide incidence and damage to high value crops: Frankliniella occidentalis (Thysanoptera: Thripidae) and Tuta absoluta (Lepidoptera: Gelechiidae). We tested 10 EPN populations belonging to three EPN species: Heterorhabditis bacteriophora (Koppert, MG-618b, AM-203, RM-102), Steinernema feltiae (Koppert, RS-5, AM-25, RM-107), and Steinernema carpocapsae (Koppert, MG-596a). Each EPN population was tested at two concentrations. Frankliniella occidentalis was tested at 160 and 80 IJs/cm2 and T. absoluta at 21 and 4 IJs/cm2. Control treatments followed the same experimental procedure but only adding distilled water. Overall, whenever different, higher IJs concentration resulted in lower adult emergence, higher larval mortality, and shorter time to kill the insects. Considering the low concentration, S. feltiae provided the best results for both insects and instars investigated, while H. bacteriophora and S. carpocapsae required a high concentration to reach similar or slightly better results. Differences among populations of each of the species were detected, but only the native populations of H. bacteriophora populations showed consistently higher control values against both insects/instar compared with the commercial one. Differences among S. feltiae and S. carpocapsae populations depended on the IJs concentration, insect, and instar. We consider S. feltiae a very promising species for their application against F. occidentalis and T. absoluta, with the Koppert population as the most consistent among the populations tested. Specific EPN-populations of S. carpocapsae and H. bacteriophora were good candidates against certain instar/insects at high concentrations. This study emphasized the importance of intraspecific variability for EPN virulence., Grants ICVV-CSIC and Koppert with the following references: 1) ref. 20194898 (ID CSIC 201912) 2) ref. 20200154 (ID CSIC 205137) 3) ref. 20202349 (ID CSIC 210825), 1) RCH is awarded by Ramon y Cajal contract award MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”: Grant RYC-2016-19939 from the Government of Spain 2) IVD is supported with a FPI-UR (2021) fellowship (Universidad de La Rioja, Spain). 3) MC is supported by a Moroccan scholarship for the Ministry of National Education, Vocational Training, Higher Education and Scientific Research, and the travel assistance associated with the grant CSIC I-COOP + 2018 grant (COOPA20231). 4) MMGT is funded by the Program JAE-Intro CSIC call 2020 (JAEINT20_EX_0939). 5) MP and DL are funded by an introduction to research fellowship from Government of La Rioja (CAR 2020)., Peer reviewed