Search results for "red palm weevil"

Association of entomopathogenic fungi with exotic red palm weevil in treated and untreated Phoenix canariensis

2011

Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) is introduced pests of established Phoenix canariensis in Sicily (Italy). A three-year field survey of R. ferrugineus generated data on species of fungal associated with larval, pupae, and adult R. ferrugineus recovered from several cadavers. Moreover specimens were collected from infested Phoenix canariensis in scattered locales in Sicily to determine also infection rates with entomopathogenic fungi over 3 years. Collection was done after overwintering period, during summer and at the beginning of autumn in palm, untreated and treated with chemical pesticides. As can be expected the highest infestation was recorded after overw…

Potential effects of Bacillus thuringiensis against adults and older larvae of Rhynchophorus ferrugineus.

2009

Pathogenicity bioassays of isolates of Beauveria bassiana on Rhynchophorus ferrugineus

2012

BACKGROUND:The control ofRhynchophorusferrugineus (Olivier), themainpalmpest in theMediterraneanBasin, is problematic because of its biology and the current restrictions inmany European countries on the use of chemical insecticides in urban areas. Entomopathogenic fungi have been studied as potential biological control agents, but information on their natural incidence is limited. Strains of Beauveria bassiana (Balsamo) Vuillemin were isolated from symptomatic insects collected on dead palms, and their pathogenicity against different instars of R. ferrugineus was evaluated in the laboratory. RESULTS: The overall percentage of infected insects found in Canary palms was 7%. In laboratory bioa…

CONTROL OF RED PALM WEEVIL POPULATION BY BEHAVIOUR-MODIFYING COMPOUNDS

Bacillus thuringiensis treatment alters larval growth, hemocytes and modulation of Hsp70 in Rhynchophorus ferrugineus

2011

To study the pathogen-host relationship, we used the model of the entomopathogenic bacterium Bacillus thuringiensis (Bt) and Rhynchophorus ferrugineus, a quarantine pest that attacks the palm trees. In particular, we focused on the Bt stress-induced infections. We studied the effect of Bt on larval growth, on hemocytes and on the expression of the heat shock proteins (Hsp70). HSPs are rapidly synthesized in the cells after a stress exposition including pathogens. The Hsp70 was evaluated in the supernatant of the hemocyte lysate (HLS) obtained from larvae fed with Bt. This is the first time that the presence of Hsp70 has been recorded in R. ferrugineus. Bt has negative effects on larval grow…

In vivo modulation of Hsp70 in Rhynchophorus ferrugineus hemocytes after Bacillus thuringiensis treatment

2010

Heat shock proteins (Hsps) are rapidly synthesized within stressed cells after exposure to an environmental stressor. A variety of environmental stresses, including heat, cold, trace-metal exposure, xenobiotics have been reported to modulate Hsps expression in various organisms. Hsps are grouped into several families based on their protein size. Most organisms have several genes encoding members of this Hsp family. In particularly Hsp70 can be induced quickly under stressful conditions, but return to a normal expression level under non-stressful conditions. Few studies have been done to detect the Hsp70 expression in phytophagous insects towards pathogens. Since a preliminary research discl…

Effect of Bacillus thuringiensis as vegetative form on hemocytes of Rhynchophorous ferrugineus (Coleoptera Curculionidae) larvae

2010

The bacterium Bacillus thuringiensis (Bt) is a pathogen of many insect species and is actively used in biocontrol. The vegetative form as been reported to be involved in insect septicemia process. Bt during the vegetative stage of growth, is known to secern a new family of insecticidal proteins. Moreover recently evidence has been provided, that B. thuringiensis can establish itself in replicative and vegetative form on the leaf surface. Little is known on the interaction of pathogens with the defense responses of phytophagous insects. Insect circulating hemocytes are primarily responsible for the immune defense against parasites and pathogens. We use as model Rhynchophorous ferrugineus Oli…

Preliminary results on antimicrobial activity of Rhynchophorous ferrugineus hemolymph

2011

Rhynchophorus ferrugineus (Coleoptera: Curculionidae), known as the Red Palm Weevil (RPW) and accidentally introduced in the Mediterranean areas, is considered a quarantine pest for tree palms especially in the urban environment. In order to understand the relationship among potential pathogens and RPW several studies were carried out on RPW immune system. Here we report the results of a preliminary study undertaken to investigate the effect of naturally occurring antimicrobial activities present both in the cell free hemolymph and in hemocytes lysate supernatant of RPW. The hemolymph was extracted from the older larvae sampled from infested palm trees. The protein fractions were extracted …

Fungi related to larvae of red palm weevil Rhynchophorous ferrugineus (Coleoptera: Curculionidae)

2010

As a first step to developing effective biocontrol strategies, we analyzed the pathogens and mainly the entomopathogenic fungal species, present into dead larvae of Rhynchophorous ferrugineus; a quarantine pest recently introduced and acclimated in Sicily (Italy). From 2008 to 2010, we estimated the natural larval mortality (> second instar) of R. ferrugineus collected from infested palm Phoenix canariensis; that was variable from 10 to 35%, according to the different seasons Among the different pathogens recorded the fungi seems have an important role, than in order to distinguish saprophytic or opportunistic species from potential pathogens (including the non cultivable ones) we applied d…

Stratégies de lutte contre le charançon rouge du palmier

2018

La communauté scientifique internationale (source : publication FAO d’avril 2017) s’accorde sur l’importance de la combinaison des mesures de lutte en fonction des niveaux d’infestation par le charançon rouge du palmier. Plusieurs mesures de lutte sont disponibles ou envisageables : assainissement mécanique, application d’insecticides à titre préventif ou curatif, piégeage de masse et biocontrôle (lutte biologique sensu stricto). Il est à noter que plusieurs expérimentations sur le biocontrôle sont en cours.Dans la perspective d’améliorer les stratégies de lutte contre le charançon rouge du palmier, il est demandé : 1) d’identifier les stratégies de lutte (en tant que combinaison de différe…