Search results for "coleoptera"
showing 10 items of 134 documents
A membrane associated metalloprotease cleaves Cry3Aa Bacillus thuringiensis toxin reducing pore formation in Colorado potato beetle brush border memb…
2007
AbstractInsect proteases are implicated in Bacillus thuringiensis insecticidal proteins mode of action determining toxin specificity and sensitivity. Few data are available on the involvement of proteases in the later steps of toxicity such as protease interaction with toxin–receptor complexes and the pore formation process. In this study, a Colorado potato beetle (CPB) midgut membrane metalloprotease was found to be involved in the proteolytic processing of Cry3Aa. Interaction of Cry3Aa with BBMV membrane proteases resulted in a distinct pattern of proteolysis. Cleavage was demonstrated to occur in protease accessible regions of domain III and was specifically inhibited by the metalloprote…
Functional significance of membrane associated proteolysis in the toxicity of Bacillus thuringiensis Cry3Aa toxin against Colorado potato beetle.
2012
Abstract Bacillus thuringiensis Cry toxins are widely used as biocontrol agents in bioinsecticides and transgenic plants. In the three domain-Cry toxins, domain II has been identified as an important determinant of their highly specific activity against insects. In this work, we assessed the role in membrane associated proteolysis and toxicity in Colorado potato beetle (CPB) of a previously reported ADAM recognition motif present in Cry3Aa toxin domain II. We used site-directed mutagenesis to modify the Bacillus thuringiensis cry3A gene in amino acid residues 344, 346, 347, 351 and 353 of the ADAM recognition motif in Cry3Aa toxin. Cry3Aa toxin mutants displayed decreased toxicity when comp…
Prohibitin, an essential protein for Colorado potato beetle larval viability, is relevant to Bacillus thuringiensis Cry3Aa toxicity
2013
Bacillus thuringienesis (Bt) Cry toxins constitute the most extensively used environmentally safe biopesticide and their mode of action relies on the interaction of the toxins with membrane proteins in the midgut of susceptible insects that mediate toxicity and insect specificity. Therefore, identification of Bt Cry toxin interacting proteins in the midgut of target insects and understanding their role in toxicity is of great interest to exploit their insecticidal action. Using ligand blot, we demonstrated that Bt Cry3Aa toxin bound to a 30kDa protein in Colorado potato beetle (CPB) larval midgut membrane, identified by sequence homology as prohibitin-1 protein. Prohibitins comprise a highl…
Pre-invasion history and demography shape the genetic variation in the insecticide resistance-related acetylcholinesterase 2 gene in the invasive Col…
2012
Abstract Background Invasive pest species offers a unique opportunity to study the effects of genetic architecture, demography and selection on patterns of genetic variability. Invasive Colorado potato beetle (Leptinotarsa decemlineata) populations have experienced a rapid range expansion and intense selection by insecticides. By comparing native and invasive beetle populations, we studied the origins of organophosphate (OP) resistance-associated mutations in the acetylcholinesterase 2 (AChE2) gene, and the role of selection and demography on its genetic variability. Results Analysis of three Mexican, two US and five European populations yielded a total of 49 haplotypes. Contrary to the exp…
Characterization ofBacillus thuringiensisserovarbolivia(serotype H63), a novel serovar isolated from the Bolivian high valleys
1999
The type strain Bacillus thuringiensis var. bolivia (serotype H63), isolated from the Bolivian high valleys, has been characterized at different levels. Its parasporal crystal has an unusual shape and it is composed of a protein of 155 kDa which shows two bands of 75 and 80 kDa after activation. Analysis by PCR shows the presence of cry1 genes, and amplification with specific primers gave products for cry1 E, cry1 D, cry4 A and cry4 B with sizes different to those expected. Immunoblotting tests showed positive reaction for Cry1 E, Cry3 A, Cry4 A and Cry11 A crystal proteins. The plasmid pattern revealed two large and two small plasmids. Toxicity tests were performed against 14 insects and a…
The genus Bolbelasmus in the western and southern regions of the Mediterranean Basin (Coleoptera: Geotrupidae: Bolboceratinae)
2016
The Bolbelasmus Boucomont, 1911 species of the western and southern regions of the Mediterranean Basin (Northern Africa, Iberian Peninsula and France) are revised. The following three new species are described: Bolbelasmus brancoi Hillert & Král sp. nov. and Bolbelasmus howdeni Hillert & Král sp. nov., both from Spain and Gibraltar, and Bolbelasmus nikolajevi Hillert, Arnone, Král & Massa sp. nov. from Egypt, Libya and Tunisia. Bolbelasmus vaulogeri (Abeille de Perrin, 1898) stat. restit. is removed from synonymy with B. bocchus (Erichson, 1841) and reinstated as a separate species. Bolbelasmus romanorum Arnone & Massa, 2010 is considered a junior subjective synonym of B. vaulogeri. Lectoty…
Indagine su Henosepilachna elaterii (Rossi) (=Epilachna chrysomelina (F.)) e Raphidopalpa foveicollis (Lucas) in meloneti biologici della Sicilia occ…
2011
Investigations on Henosepilachna elaterii (Rossi) and Raphidopalpa foveicollis (Lucas) in an organic cultivation of winter melon in western Sicily. A study on H. elaterii and R. Foveicollis, serious pests of winter melon, was conducted in two organic melon fields of the western Sicily. Dynamics of population and infestation levels were investigated. In addition, the possible influence of mulching on R. Foveicollis infestation has been taken into account. Our results showed that H. elaterii occurred only in one field from the beginning of June and it infested 60% of the plants in the mid-July, then the pest population density dropped to about 10%. R. foveicollis occurred in both locations fr…
Individuazione e applicazione di composti volatili repellenti per il controllo delle popolazioni del punteruolo rosso delle palme
2014
The red palm weevil (RPW), Rhynchophorus ferrugineus Olivier (Coleoptera, Curculionidae), is one of the most severe pests of ornamental palm species in urban areas of Mediterranean countries. The cryptic nature of the weevil, and the gaps in our knowledge of its biology and ecology, hamper the development of efficient and sustainable strategies to limit its diffusion. Control strategies based on semiochemicals can be considered a suitable alternative for RPW population management, particularly in urban areas. Nevertheless these strategies might be improved by broadening our knowledge of behavior modifying stimuli suitable for adult manipulation, such as repellent chemical compounds. A first…
Strelitzia nicolai (Strelitziaceae), new host plant for Rhynchophorus ferrugineus (Coleoptera Curculionidae) in Sicily.
2015
The Red Palm Weevil Rhynchophorus ferrugineus (Olivier, 1790) (Coleoptera Curculionidae), is con- sidered the main palm pest in the Mediterranean basin. This species is native to Southeastern Asia and is now widely spread throughout Oceania, Africa, Europe and the Caribbean (MURPHY & BRISCOE, 1999; EPPO, 2008, 2012; CHEBBI et al., 2011; RODA et al., 2011). Moreover, in North America the pest was found in California, where it is now considered eradicated (CDFA, 2010; IPPC, 2015). In Italy the first registered sightings were on nursery palms in Tuscany (SACCHETTI et al., 2005, 2006) and on ornamental palms in urban areas in Sicily (LONGO & TAMBURINO, 2005; LO VERDE & MASSA, 2007). Afterwards,…
PALAZZO STERI DI PALERMO, SOFFITTO LIGNEO DELLA SALA MAGNA INDAGINE FITOSANITARIA
2012
ABSTRACf - Steri Palace of Palermo; Wooden Ceiling of the "Sala Magna ", Phytosanitary Survey. The Steri Palace (from Hosterium = fortified residence) of Palermo was built in the early fourteenth century, exactly from 1307 to 1320, it was Chiaramonte's family residence. Later, it became the seat of the viceroy of Sicily (from 1412 to 1577), of the Director of the Royal "Magna Curia", and Royal Customs (until 1698), of the Inquisition Tribunal (from 1701 to 1792), of the Judicial offices and Custom offices (from 1800 to 1958). Today it is the Centre of the Chancellor's offices of the University of Palermo. It contains several interesting cultural heritage artefacts, including the beautiful d…