Formulation technology has been the primordial focus to improve the low viability and erratic infectivity of entomopathogenic nematodes (EPNs) for foliar application. Adaptability to the fluctuating environment is a key trait in ensuring the survival and efficacy of EPNs. Hence, tailoring formulations towards EPNs foliar applications would effectively deliver consistent and reliable results for above-ground applications.
View Article and Find Full Text PDFEntomopathogenic nematodes (EPN) species differ in their capability to withstand rapid desiccation (RD). Infective juveniles of Steinernema carpocapsae are a better adaptable and tolerant than Steinernema feltiae or Heterorhabditis bacteriophora as, an optimal RH of > 90% is required by S. feltiae and H.
View Article and Find Full Text PDFAs the larvae of the date palm pest, the red palm weevil, Rhynchophorus ferrugineus, feeds on the host tissue, they emit a distinctive sound which can be recorded outside of the infected tree. We evaluated the response of infective juveniles (IJs) of the entomopathogenic nematodes Steinernema carpocapsae to the R. ferrugineus larvae and it's sound source, separately.
View Article and Find Full Text PDFEntomopathogenic nematodes are effective biocontrol agents against arthropod pests. However, their efficacy is limited due to sensitivity to environmental extremes. The objective of the present study was to establish a foundation of genetic-based selection tools for beneficial traits of heat and desiccation tolerance in entomopathogenic nematodes.
View Article and Find Full Text PDFAs gastro-intestinal nematodes (GINs) become increasingly resistant to chemical anthelmintics, and because consumers scrutinize chemical residues in animal products, the use of herbal anthelmintics and in particular, phenolic compounds, has become attractive. Most life stages of GINs cannot be grown in the lab as they are obligatory parasites, which limits our understanding of the effects of phenolic compounds on their parasitic stages of life. We hypothesized that a species phylogenetically close to GINs and grown in vitro, the insect-parasitic nematode Heterorhabditis bacteriophora (Rhabditida; Heterorhabditiade), when fed with Photorhabdus luminescens exposed to plant phenolics, can serve, as proxy for strongyles, in assessing the anthelmintic effects of phenolic compounds.
View Article and Find Full Text PDFInsects show adaptive plasticity by ingesting plant secondary compounds, such as phenolic compounds, that are noxious to parasites. This work examined whether exposure to phenolic compounds affects the development of insect parasitic nematodes. As a model system for parasitic life cycle, we used Heterorhabditis bacteriophora (Rhabditida; Heterorhabditiade) grown with Photorhabdita luminescens supplemented with different concentrations of plant phenolic extracts (0, 600, 1200, 2400 ppm): a crude ethanol extract of lentisk (Pistacia lentiscus) or lentisk extract fractionated along a scale of hydrophobicity with hexane, chloroform and ethyl acetate; and flavonoids (myricetin, catechin), flavanol-glycoside (rutin) or phenolic acids (chlorogenic and gallic acids).
View Article and Find Full Text PDFHeterorhabditis bacteriophora can represent a model system for herbal medication against gastro-intestinal strongylid parasites in determining the recovery and development due to their unique parasitic infectious cycle. The fact that plant extracts impair nematode development is known but their differential impact on stages of the life cycle of H. bacteriophora has never been investigated.
View Article and Find Full Text PDFEntomopathogenic nematodes of the genus Steinernema are effective biological control agents. The infective stage of these parasites can withstand environmental stresses such as desiccation and heat, but the molecular and physiological mechanisms involved in this tolerance are poorly understood. We used 454 pyrosequencing to analyse transcriptome expression in Steinernema spp.
View Article and Find Full Text PDFParasitized animals can self-medicate. As ingested plant phenolics, mainly tannins, reduce strongyle nematode infections in mammalian herbivores. We investigated the effect of plant extracts known to be anthelmintic in vertebrate herbivores on the recovery of the parasitic entomopathogenic nematode Heterorhabditis bacteriophora infecting African cotton leafworm (Spodoptera littoralis).
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