Search results for "Entomopathogenic nematode"
showing 5 items of 5 documents
Investment in multiple defences protects a nematode-bacterium symbiosis from predation
2017
The act of predation often comprises multiple sequential steps whereby prey can employ defences at all or some of these stages to deter predation. However, investment in defences is costly unless they are outweighed by conferring some benefit to the bearer. One system that employs multiple defences is that of the entomopathogenic nematode Heterorhabditis bacteriophora and its symbiotic bacterium Photorhabdus luminescens. This nematodeebacterium complex infects and kills soil-dwelling insect larvae, in which they then reproduce and juveniles emerge 2 weeks later. Predation of the infected host cadaver at any point during infection is fatal for the parasitic colony inside. Infected individual…
Biological Responses of <I>Rhynchophorus ferrugineus</I> (Coleoptera: Curculionidae) to <I>Steinernema carpocapsae</I> (Nemat…
2013
Rhynchophorus ferrugineus (Olivier 1790) (Coleoptera: Curculionidae) is becoming a serious problem in Mediterranean areas where it is well-adapted, and now is present even in the United States (California). The infestations are primarily in urban areas where chemical control is not advisable and million of Euros are spent to control it. The effects of the entomopathogenic nematode Steinernema carpocapsae (Nematoda: Steinernematidae) on mortality, growth, as well as the immune activity of R. ferrugineus larvae, were investigated. R. ferrugineus mortality exhibited a positive trend with the dosage and duration of exposure to S. carpocapsae. The median lethal dose and median lethal time, impor…
Modulation of immune responses ofRhynchophorus ferrugineus(Insecta: Coleoptera) induced by the entomopathogenic nematodeSteinernema carpocapsae(Nemat…
2014
Aim of this study was to investigate relationships between the red palm weevil (RPW) Rhynchophorus ferrugineus (Olivier) and the entomopathogenic nematode Steinernema carpocapsae (EPN); particularly, the work was focused on the immune response of the insect host in naive larvae and after infection with the EPN. Two main immunological processes have been addressed: the activity and modulation of host prophenoloxidase-phenoloxidase (proPO) system, involved in melanization of not-self and hemocytes recognition processes responsible for not-self encapsulation. Moreover, immune depressive and immune evasive strategies of the parasite have been investigated. Our results suggest that RPW possess a…
Pristionchus sp. (Rhabditida: Diplogastridae) from Italian populations of Anoplophora chinensis Forster (Coleoptera: Cerambycidae).
2009
Priostonchus sp. n. (Rhabditida: Diplogastridae) is described from a population of Citrus Longhorn Beetles. Alive adults of this Cerambycid were collected from Acer saccharinum trees at Assago and Parabiago (Villastanza), two localities near Milan (Italy). The natural occurrence of the entomogenous nematode in the beetle was not frequent and widespread in the study area. Preliminary laboratory infectivity tests highlight the potential parasitic nature of the nematode. However, it was not successfully maintained in storage and culture. The diplogasterid Pristionchus sp. has rather complicate systematic thus a biomolecular analysis based on DNA is necessary for more specific identification an…
Biological responses of Rhynchophorous ferrugineus to Steirnenema carpocapase: an example of a model system
2011
Rhynchophorus ferrugineus (Coleoptera: Curculionidae) known as the Red Palm Weevil (RPW) is becoming more and more of a problem in Italy, and especially in Sicily, where it is well adapted. The infestations are mainly in the urban areas, and for that reason, chemical control is not advisable. Data from literature show that entomopathogenic nematodes (EPN) control RPW quite successfully in the field. However, results coming from the laboratories are often in contrast with each other and no data are available on precise doses. In this context we studied the Median Lethal Dose (DL50) and the Median Lethal Time (TL50) of young and older larvae and also of adults. The doses for the adults were t…