Search results for "Weevil"

Analisi molecolare per lo studio della variabilità genetica nel Punteruolo rosso

2009

Al fine di caratterizzare e confrontare le popolazioni di Rhynchophorus ferrugineus presenti in Sicilia, con quelle presenti negli areali autoctoni e di recente introduzione, sono stati messi a punto dei protocolli per l’analisi di specifiche sequenze del DNA genomico di questo fitofago. Sono stati disegnati i primer da utilizzare per l’amplificazione della regione ITS del punteruolo rosso. In particolare, per l’amplificazione della porzione ITS1 un primer forward è posizionato nella porzione terminale del gene 18S (P1) e l’altro nella porzione iniziale del gene 5,8S (P2), con opposta direzione di sintesi.Per l’amplificazione dell’ITS2, invece, i primer forward e reverse sono posizionati, r…

Bacillus thuringiensis treatment modulate the HSP70 expression in larva and adult brain of Rhynchophorus ferrugineus

2013

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 palm trees. In particular, we focused on the Bt stress-induced infections. We studied the effect of Bt on larval and adult growth, and on the expression of the heat shock proteins (HSPs), rapidly synthesized in the cell after exposure to stress including pathogens. Bt has negative effects on larval and adult growth, on total hemocytes counts and on the hemocyte type. HSP70 was evaluated in the supernatant of the brain lysate obtained from larvae and adults fed with sublethal doses of Bt. HSP70 expression was mo…

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 …