Search results for "Insect Science"
showing 10 items of 1011 documents
Sciaridae (Diptera) from central Finland: faunistics and taxonomy
2005
Sciaridae (Diptera) from forest and mire habitats from three localities in central Finland were identified. The material consisted of 609 specimens belonging to 106 species. The following species were found as new to Finland: Bradysia subbetuleti, B. submoesta, B. subscabricornis, Corynoptera fera, C. furcifera, C. saetistyla, C. subsedula, Cratyna spiculosa, Leptosciariella helvetica, Lycoriella micria, Pseudolycoriella brunnea, P. nodulosa, Scatopsciara neglecta, Trichosia glabra and Sciara sp. n. (Menzel & Salmela, in prep.) and Ctenosciara exigua sp. n. The latter is described as new to science. Bradysia subbetuleti, Leptosciariella atricha, Leptosciariella tuberculigera and Lycorie…
Fate of the herbicides glyphosate, glufosinate-ammonium, phenmedipham, ethofumesate and metamitron in two Finnish arable soils.
2006
The fate of five herbicides (glyphosate, glufosinate-ammonium, phenmedipham, ethofumesate and metamitron) was studied in two Finnish sugar beet fields for 26 months. Soil types were sandy loam and clay. Two different herbicide-tolerant sugar beet cultivars and three different herbicide application schedules were used. Meteorological data were collected throughout the study and soil properties were thoroughly analysed. An extensive data set of herbicide residue concentrations in soil was collected. Five different soil depths were sampled. The study was carried out using common Finnish agricultural practices and represents typical sugar beet cultivation conditions in Finland. The overall obse…
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…
Enhanced baculovirus-mediated transduction of human cancer cells by tumor-homing peptides.
2006
ABSTRACT Tumor cells and vasculature offer specific targets for the selective delivery of therapeutic genes. To achieve tumor-specific gene transfer, baculovirus tropism was manipulated by viral envelope modification using baculovirus display technology. LyP-1, F3, and CGKRK tumor-homing peptides, originally identified by in vivo screening of phage display libraries, were fused to the transmembrane anchor of vesicular stomatitis virus G protein and displayed on the baculoviral surface. The fusion proteins were successfully incorporated into budded virions, which showed two- to fivefold-improved binding to human breast carcinoma (MDA-MB-435) and hepatocarcinoma (HepG2) cells. The LyP-1 pepti…
Influence of temperature and photoperiod on embryonic development in the dragonflySympetrum striolatum(Odonata: Libellulidae)
2015
Temperature and photoperiod play major roles in insect ecology. Many insect species have fixed degree-days for embryogenesis, with minimum and maximum temperature thresholds for egg and larval development and hatching. Often, photoperiodic changes trigger the transfer into the next life-cycle stadium. However, it is not known whether this distinct pattern also exist in a species with a high level of phenotypic plasticity in life-history traits. In the present study, eggs of the dragonfly Sympetrum striolatum Charpentier (Odonata: Libellulidae) are reared under different constant and fluctuating temperatures and photoperiodic conditions in several laboratory and field experiments. In general…
Morphological adaptation in host races of Tephritis conura
2007
The present study investigates morphological differentiation among host races of the fruit fly Te phritis conura Loew (Diptera: Tephritidae) for two fitness-related traits and whether these traits are host induced or genetically determined. Flies were analyzed from independent sympatric regions, and from one syntopic site where parental host plants [ Cirsium heterophyllum (L.) Hill. and Cirsium oleraceum (L.) Scop. (Cardueae)] and hybrid plants ( C. heterophyllum × C. oleraceum ) co-occur. As both host races may oviposit on hybrid plants and hybrid plants provide an identical environment for larvae of both host races, flies emerging from C. heterophyllum × C. oleraceum hybrids were used to …
Candidate target mechanisms of the growth inhibitor cyromazine: Studies of phenylalanine hydroxylase, puparial amino acids, and dihydrofolate reducta…
2000
Cyromazine, an insect growth regulator, affects larval and pupal cuticles in dipterans and some other insects. The mode of action of this aminotriazine is not known yet, though it has been shown not to inhibit the synthesis of chitin and cuticular proteins. Cyromazine may, however, act on some step(s) of sclerotization of the cuticle. In the present study, we have analyzed the key enzyme for the production of sclerotization agents, phenylalanine hydroxylase (PAH), using the enzyme from Drosophila, a cyromazine-sensitive insect. PAH was studied in vitro with cyromazine and three biologically less active derivatives at concentrations ranging from 1 μM to 1 mM. None of the compounds did signif…
Diversity and distribution of feather lice on Greater Flamingoes (Phoenicopterus ruber roseus) in the Camargue, southern France
2002
Feather lice were collected from 2S0 chicks of the Greater Flamingo (Phoenicopterus ruber roseus Pallas) captured alive in the Camargue, southern France, in July 1997. Five louse species were identified: Colpocephalum heterosoma Piaget, Colpocephalum salimalii Clay and Trinoton femoratum Piaget of the family Menoponidae; Anaticola phoenicopteri (Coinde) and Anatoecus pygaspis (Nitzsch [in Giebel]) of the family Philopteridae. Our collecting results also show that there is body-site segregation among the several louse species inhabiting the same host individual.
The Pandinus imperator haemolymph lipoprotein, an unusual phosphatidylserine carrying lipoprotein.
2009
The haemolymph lipoprotein of the scorpion, Pandinus imperator was isolated and characterised. Contrary to the lipoproteins of insects and the discoidal HDL-lipoproteins of a crayfish and polychaete, the Pandinus lipoprotein consists of three instead of two apoproteins (apoPiLp I = 230 kDa, apoPiLp II = 130 kDa and apoPiLp III = 120 kDa). The apolipoproteins are arranged in varying stoichiometries as judged by cross-linking experiments. In lipoprotein samples from individual animals, the two smaller subunits occurred in a 1:1 stoichiometry, while the relative amount of the 230 kDa peptide varied. The lipoprotein is a slightly heart-shaped HDL with a diameter of approximately 15 nm. It is pr…
Progress in the characterization of insulin-like peptides in aphids: Immunohistochemical mapping of ILP4.
2021
Aphids were the first animals described as photoperiodic due to their seasonal switch from viviparous parthenogenesis to sexual reproduction (cyclical parthenogenesis) caused by the shortening of the photoperiod in autumn. This switch produces a single sexual generation of oviparous females and males that mate and lay diapausing cold-resistant eggs that can overcome the unfavourable environmental conditions typical of winter in temperate regions. Previous studies have hinted at a possible implication of two insulin-like peptides (ILP1 and ILP4) in the aphid seasonal response, changing their expression levels between different photoperiodic conditions. Moreover, in situ localization of their…