Intraspecific virulence of entomopathogenic nematodes against the pests Frankliniella occidentalis (Thysanoptera: Thripidae) and Tuta absoluta (Lepidoptera: Gelechiidae)

Digital.CSIC. Repositorio Institucional del CSIC
  • Campos-Herrera, R.
  • Vicente-Díez, Ignacio
  • Galeano, Magda
  • Chelkha, Maryam
  • González-Trujillo, M.
  • Puelles, Miguel
  • Labarga, David
  • Pou, Alicia
  • Calvo-Garrido, Javier
  • Belda, J. E.
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., 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. IVD is supported with a
FPI-UR (2021) fellowship (Universidad de La Rioja,
Spain). 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). MMGT
is funded by the Program JAE-Intro CSIC call 2020
(JAEINT20_EX_0939). MP and DL are funded by an
introduction to research fellowship from Government
of La Rioja (CAR 2020). The study was performed
under the Research and Innovation grant at CSIC ref.
20200154 and 20194898., Peer reviewed

Digital.CSIC. Repositorio Institucional del CSIC

Digital.CSIC. Repositorio Institucional del CSIC
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Digital.CSIC. Repositorio Institucional del CSIC