Nematicidal Effects of Four Terpenes Differ among Entomopathogenic Nematode Species

Vasileios Kotsinis, Alexandros Dritsoulas (), Dionysios Ntinokas and Ioannis O. Giannakou
Additional contact information
Vasileios Kotsinis: Laboratory of Agricultural Zoology and Entomology, Department of Crop Science, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece
Alexandros Dritsoulas: Laboratory of Agricultural Zoology and Entomology, Department of Crop Science, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece
Dionysios Ntinokas: Laboratory of Agricultural Zoology and Entomology, Department of Crop Science, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece
Ioannis O. Giannakou: Laboratory of Agricultural Zoology and Entomology, Department of Crop Science, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece

Agriculture, 2023, vol. 13, issue 6, 1-11

Abstract: Entomopathogenic nematodes (EPNs) have been studied for more than half a century, and employed for insect pest management using augmentation, conservation, and classical biological control approaches. As obligate lethal parasitoids of insect larvae, EPN navigate a chemically complex soil environment and interact with their insect hosts, plants, and each other. EPN responses to various terpenes, such as herbivore-induced plant volatiles, have the potential to enhance EPN efficacy through their attraction. However, several of the terpenes are currently being formulated as biological fungicides, insecticides, and acaricides for above- or below-ground applications. We conducted laboratory experiments to investigate the possible nematicidal effect of four terpenes, carvacrol, geraniol, eugenol, and thymol, to two heterorhabditids and two steinernematid species. Each terpene showed nematicidal activity against at least two of the four EPN species, with carvacrol showing the strongest activity and Heterorhabditis bacteriophora the highest sensitivity. Despite the high sensitivity of both heterorhabditids and near-zero sensitivity of the steinernematids to thymol, carvacrol, and eugenol, an increasing effect was observed when steinermatid nematodes were exposed to geraniol, and a decreasing effect for heterorhabditids, with H. bacteriophora exhibiting higher mortality than H. indica . The virulence of the nematodes towards fourth instar Galleria mellonella was also tested after exposure to the median lethal doses of each terpene. No significant difference in virulence was observed between nematodes that were exposed or not exposed to sublethal doses. The experiments suggest that the tested terpenes have a strong effect on EPN viability, which should be considered when combining the two approaches in IPM. The terpenes did not have a universal effect on all nematode species, which merits further investigation, while virulence tests suggest that sublethal doses of these terpenes have no effect on the host-killing performance of EPNs.

Keywords: entomopathogenic nematodes; terpenes; nematicidal activity; eugenol; carvacrol; thymol; carvacrol; nematostatic activity (search for similar items in EconPapers)
JEL-codes: Q1 Q10 Q11 Q12 Q13 Q14 Q15 Q16 Q17 Q18 (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2077-0472/13/6/1143/pdf (application/pdf)
https://www.mdpi.com/2077-0472/13/6/1143/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jagris:v:13:y:2023:i:6:p:1143-:d:1158436

Access Statistics for this article

Agriculture is currently edited by Ms. Leda Xuan

More articles in Agriculture from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().