Search results for "Coleoptera"

Population dependent effects of photoperiod on diapause related physiological traits in an invasive beetle (Leptinotarsa decemlineata).

2012

Organisms undergoing latitudinal range expansion face a change in the photoperiod which can lead to a mismatch between the timing of seasonal changes in physiological and life history traits with seasonal environmental changes. This mismatch can lead to lowered survival, for example, due to unsynchronized diapause timing. Successful range expansion even in recent introductions requires that organisms which use the photoperiod for seasonal predictions should show interpopulational differences in photoperiodic responses at different latitudes, as the photoperiod is a function of latitude. We investigated among population differences in photoperiodic responses of life history and physiological…

"KARYOTYPE, BANDING AND rDNA FISH IN THE SCARAB BEETLE ANOPLOTRUPES STERCOROSUS (COLEOPTERA SCARABAEOIDEA: GEOTRUPIDAE). DESCRIPTION AND COMPARATIVE …

2004

Six specimens of Anoplotrupes stercorosus (Coleoptera Scarabaeoidea: Geotrupidae) were analysed using conventional staining, banding techniques and fluorescent in situ hybridization with a ribosomal probe (rDNA FISH). Detailed karyotype description was also joined to a comparative analysis between present data and those previously reported for Thorectes intermedius [Chromosome Res. 7 (1999) 1]. The two species, both belonging to the tribe Geotrupini, show the same modal number but different autosomal morphology which is in contrast with the high chromosome stability argued for Geotrupinae during the last three decades. Moreover, a detailed comparison reveals the occurrence of a plesiomorphi…

No evidence of androgenic hormone from the testes of the glowworm, Lampyris noctiluca.

2005

The widely accepted concept, stating that insects have no true sex hormones, and that primary as well as secondary sex characteristics are controlled by the genetic inventory of each single cell, is challenged by the report of Naisse, J. [1966a. Controle endocrinien de la differenciation sexuelle chez l'Insecte Lampyris noctiluca (Coleoptere Malacoderme Lampyride). I. Role androgene des testicules, Arch. Biol. Liege, 77, 139-201] on the discovery of an androgenic hormone in the glowworm, Lampyris noctiluca. This case is of special interest, since it may point to an ancestral mode of sex differentiation in arthropods, considering that androgenic hormones have been discovered and characterize…

The Independent Biological Activity of Bacillus thuringiensis Cry23Aa Protein Against Cylas puncticollis

2020

The Cry23Aa/Cry37Aa proteins from Bacillus thuringiensis (Bt) have been described toxic to Cylas puncticollis larvae. In general, it is believed that Cry23Aa and Cry37Aa act jointly to exert the insecticidal activity, while there is no evidence of their toxicity individually. Therefore, in the present study, the contribution of each protein in the insecticidal activity toward C. puncticollis larvae has been assessed. The results showed that both proteins were toxic for C. puncticollis larvae when tested individually. Contrary to what was claimed previously, our results suggest that the presence of both proteins is not necessary to exert toxicity against C. puncticollis larvae. Also, the bin…

Primi dati di Morfometria Geometrica di Phaleria bimaculata (Coleoptera, Tenebrionidae) nella zona del Mediterraneo centrale.

2011

SICILIAN NATURALISTIC NEWS: 8 Muscicapa striata tyrrhenica; 9 Garella (Characoma) nilotica; 10 Mycterus curculioides.

2021

SICILIAN NATURALISTIC NEWS: 8 aMediterranean Flycatcher Muscicapa striata tyrrhenica Schiebel, 1910 (Aves Muscicapidae); 9 Garella (Characoma) nilotica (Rogenhofer, 1881) (Lepidoptera Nolidae) 10 Mycterus curculioides Fabricius, 1781 (Coleoptera Mycteridae)

OZOGNATHUS CORNUTUS (LECONTE, 1859) (Coleoptera Anobiidae), NEW RECORD FOR ITALY

2014

Prima segnalazione di Ozognathus cornutus (LeConte, 1859) (Coleoptera Anobiidae) in Italia

Biochemistry and genetics of insect resistance to Bacillus thuringiensis.

2001

▪ Abstract  Bacillus thuringiensis (Bt) is a valuable source of insecticidal proteins for use in conventional sprayable formulations and in transgenic crops, and it is the most promising alternative to synthetic insecticides. However, evolution of resistance in insect populations is a serious threat to this technology. So far, only one insect species has evolved significant levels of resistance in the field, but laboratory selection experiments have shown the high potential of other species to evolve resistance against Bt. We have reviewed the current knowledge on the biochemical mechanisms and genetics of resistance to Bt products and insecticidal crystal proteins. The understanding of th…

Reactive oxygen and ethylene are involved in the regulation of regurgitant-induced responses in bean plants.

2004

Summary Application of regurgitant from Leptinotarsa decemlineata Say on wound surfaces of one wounded leaf of intact bean ( Phaseolus vulgaris L.) plants resulted in activation of ethylene biosynthesis followed by an increase of both peroxidase and polyphenol oxidase activity. The aim of the present investigation was to study the source of increased oxidative enzyme activities in regurgitant-treated bean leaves and to determine if hydrogen peroxide and ethylene biosynthesis is responsible for regurgitant-induced amplification of wound responses in bean plants. As the regurgitant contained relative high activities of both peroxidase and polyphenol oxidase, there is a possibility that increa…

Role of toxin activation on binding and pore formation activity of the Bacillus thuringiensis Cry3 toxins in membranes of Leptinotarsa decemlineata (…

2004

AbstractBinding and pore formation constitute key steps in the mode of action of Bacillus thuringiensis δ-endotoxins.In this work, we present a comparative analysis of toxin-binding capacities of proteolytically processed Cry3A, Cry3B and Cry3C toxins to brush border membranes (BBMV) of the Colorado potato beetle Leptinotarsa decemlineata (CPB), a major potato coleopteran-insect pest. Competition experiments showed that the three Cry3 proteolytically activated toxins share a common binding site. Also heterologous competition experiments showed that Cry3Aa and Cry3Ca toxins have an extra binding site that is not shared with Cry3Ba toxin. The pore formation activity of the three different Cry…