Immune defenses of Agriotes lineatus larvae against entomopathogenic nematodes

Abstract

The present work describes the immune response of wireworm larvae, Agriotes lineatus (L.) (Coleoptera: Elateridae) when challenged with two species of entomopathogenic nematodes (EPNs), Steinernema feltiae (Filipjev) (Strongyloidea: Steinernematidae) and Heterorhabditis bacteriophora (Poinar) (Rhabiditoidea: Heterorhabditidae). Two main immunological processes including cellular and humoral\ud reactions have been addressed. Total haemocyte counts after infection with H. bacteriophora increased quickly in initial times, but decreased over time post-injection (at 12 hrs and 16 hrs), instead, haemocyte numbers after infection with S. feltiae was unchanged in the early stage, but significantly decreased until 16 hrs post-injection. Plasmatocytes and granulocytes showed more significant changes compared to other haemocytes. The encapsulation response to parasites was significantly different against two nematode species; particularly, S. feltiae was almost unrecognized by host\ud haemocytes (5.85% of encapsulated parasites), assays with H. bacteriophora showed 23.5% of encapsulated nematodes. From 8 to 12 hours after H. bacteriophora infection, an increase in phenoloxidase activity was detected, while in the larvae injected with S. feltiae the enzymatic activity decreased gradually reaching the lowest level 16 hours post-injection. This is the first report on the modulation of immune response of wireworm larvae after infection with entomopathogenic nematodes

Nematode Pathogenesis of Insects and Other Pests

“…laumondii, were described from Iranian isolates of H. bacteriophora using 16S ribosomal RNA gene sequence and phenetic characters, which were collected from soil in Mashhad, Razavi Khorasan province, Iran (Karimi, Mokarm, & Hasani-Kakhki, 2012). Also, symbiotic bacteria of native H. bacteriophora from potato fields in Farooj, North Khorasan province, Iran and characterized as Photorhabdus luminescens based on main phenotypic and molecular characteristics (Rahatkhah et al, 2015). These results provide new insights for the biodiversity of bacto-helminthic complex in Iran.…”

“…In a regional survey, two native isolate of EPNs, H. bacteriophora and S. feltiae were isolated from soil in Bojnourd, North Khorasan Province (Kamali et al, 2013). Moreover, during postharvest season of potato tuber, native EPNs were collected from potato fields in Farooj, North Khorasan province, Iran and characterized as H. bacteriophora and S. feltiae (Rahatkhah et al, 2015). These results indicated that the country has a rich fauna biodiversity resource of EPNs and therefore, it could be an opportunity for discovery of new nematode species and populations from other provinces.…”

“…Recently, immune reactions of Agriotes lineatus (L.) (Coleoptera: Elateridae) and G. mellonella larvae (as susceptible host) against native isolates of EPN species, H. bacteriophora and S. feltiae is being investigated (Rahatkhah, 2015). Their study provided the first insight into survey on immune system of wireworms against EPNs in Iran.…”

Changes in protein profile and encapsulation avoiding responses of entomopathogenic nematode in the American bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

“…On the other hand, in the rose sawfly Arge ochropus (Gmelin), the cellular responses were weaker to S. carpocapsae than in H. bacteriophora (Sheykhnejad et al 2014). In another study, 6% encapsulation of S. feltiae was reported, while it was 24% in H. bacteriophora in Agriotes lineatus (L.) (Rahatkhah et al 2015). Obtained results showed that the S. abbasi isolate CS 2 had the strong capability to avoid encapsulation responses in larval H. armigera leading to the death of larvae within a very short time.…”

Global distribution of entomopathogenic nematodes, Steinernema and Heterorhabditis

“…arasbaranense (Nikdel et al, 2011) was described from East Azerbaijan province. Other surveys resulted in some already described species viz., S. glaseri, S. carpocapsae, S. bicornutum, S. kraussei (Karimi et al, 2009;Kary et al, 2009;Nikdel et al, 2008Nikdel et al, , 2010Ebrahimi and Niknam, 2011;Nikdel and Niknam, 2015;Rahatkhah et al, 2015).…”