Laboratory and field evaluation of entomopathogenic nematodes for control of Agriotes obscurus (L.) (Coleoptera: Elateridae)

Abstract

The susceptibility of the dusky wireworm, Agriotes obscurus (L.) (Coleoptera: Elateridae), to different species and strains of entomopathogenic nematodes was tested in a virulence assay in the laboratory. Larvae were exposed to different nematode doses of 50 and 100 IJs/cm2. At a dose of 50 IJs/cm2, only a commercial strain Heterorhabditis bacteriophora Poinar and the native strain Steinernema carpocapsae (Weiser) B14 caused increased mortality compared with the control (11.1% and 13.3% mortality, respectively). At the higher dose tested, all strains (except Steinernema sp. D122) were virulent to A. obscurus larvae. Steinernema carpocapsae B14 caused higher mortality of wireworm (75.6%) and was used for the assay conducted in cages, with a dose of 100 IJs/cm2, in field conditions. The results showed that S. carpocapsae B14 controlled 48.3% of A. obscurus larvae, demonstrating that some entomopathogenic nematodes have the potential to control larvae of A. obscurus. However, further work is needed to improve their efficacy.

Foliar Application of Entomopathogenic Nematodes against Cereal Leaf Beetle Oulema melanopus L. (Coleoptera: Chrysomelidae) on Wheat

“…Both our results and findings of Laznik et al [22] indicate a high sensitivity of the cereal leaf beetle O. melanopus to entomopathogenic nematodes compared with other species of beetles such as the Colorado potato beetle (Leptinotarsa decemlineata (Say)) [28,29], common cockchafer [Melolontha melolontha (L.)], rice weevil (Sitophilus oryzae (L.)) [30] and Agriotes obscurus (L.) [31].…”

The lure of hidden death: development of an attract-and-kill strategy against Agriotes obscurus (Coleoptera: Elateridae) combining semiochemicals and entomopathogenic nematodes

“…That EPNs can cause significant wireworm mortality was already known (Morton and Garcia-del-Pino, 2016), but ours appears to be the first study to show that EPNs can negatively affect wireworm feeding activity. Supplementing the formulation with an attractive plant extract enhanced the control potential of the EPNs considerably.…”

“…Relatively strong virulence has been found for H. bacteriophora (strain UWS1), causing a 67% mortality of A. lineatus larvae three weeks after inoculation (Ansari et al, 2009). Morton and Garcia-Del-Pino (2016) tested the susceptibility of A. obscurus to S. carpocapsae (B14) and found that initial EPN concentration is critical, observing 13.3% mortality at the rate of 50 IJs/cm 2 , and increasing to 75.6% when the concentration of IJs were 100 IJs/cm 2 . It is noteworthy that we had <50% mortality, but the concentration of 10 IJs/cm2 were 5 and 10 times lower than those tested by Morton and García del Pino (2016) Encapsulating EPNs in alginate beads may increase their shelf life as well as their survival in the field by offering them shelter and protection against environmental stress such as drought, UV or pathogens (Kim et al, 2014;2021).…”

Effect of Host Size on Susceptibility of Melanotus communis (Coleoptera: Elateridae) Wireworms to Entomopathogens

“…using an “attract-and-kill” strategy ( Brandl et al ., 2017 ) and on application to cover crops ( Reinbacher et al ., 2021 ). The variability and low overall virulence observed in some pathogen/wireworm studies ( Morton and Garcia-del-Pino, 2017 ; Sandhi et al ., 2020 ; Sandhi et al ., 2021 ), including the current study, may be due to the inability of the pathogen to enter the wireworm’s body through either natural openings or intersegmental membrane, in the case of nematodes ( Eidt and Thurston, 1995 ), or via the cuticle, in the case of fungi ( Zhang et al ., 2014 ). Immune responses of wireworms also serve as a defense against EPN infection ( Eidt and Thurston, 1995 ; Rahatkhah et al ., 2015 ).…”