Search results for "Epido"
showing 10 items of 238 documents
Baculovirus infection affects caterpillar chemoperception
2021
International audience; Baculoviruses are double-stranded DNA entomopathogenic viruses that infect predominantly insects of the order Lepidoptera. Research in the last decade has started to disentangle the mechanisms underlying the insect-virus interaction, particularly focusing on the effects of the baculovirus infection in the host's physiology. Among crucial physiological functions, olfaction has a key role in reproductive tasks, food source detection and enemy avoidance. In this work, we describe that Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) induces expression changes in some odorant receptors (ORs)-the centrepiece of insect's olfaction-when infecting larvae from its nat…
Fine Structure of Antennal Sensilla of Paysandisia archon and Electrophysiological Responses to Volatile Compounds Associated with Host Palms
2014
Paysandisia archon (Lepidoptera: Castniidae) is a serious pest of palm trees. A comprehensive knowledge of the insect olfactory system is essential for the development of efficient semiochemical-based control methods. The olfactory sensilla are located particularly on the antennae, and these can detect plant volatiles that provide important cues for the insects in the search for their host plants. To date, the fine structure of P. archon antennal sensilla studies and their role in host-plant perception have not been investigated in great detail. Using light microscopy and scanning and transmission electron microscopy, the antennae of both sexes of P. archon are described here in detail, acc…
New species of oribatid mites of the genera Lepidozetes and Scutozetes (Acari, Oribatida, Tegoribatidae) from Nepal
2013
Two new species of oribatid mites, Lepidozetes acutirostrum sp. n. and Scutozetes clavatosensillus sp. n., are described from Nepal. The genera Lepidozetes and Scutozetes are recorded for the first time for the Oriental region. The identification keys to the known species of these genera are provided.
Hybridization selects for prime‐numbered life cycles in Magicicada: An individual‐based simulation model of a structured periodical cicada population
2020
Abstract We investigate competition between separate periodical cicada populations each possessing different life‐cycle lengths. We build an individual‐based model to simulate the cicada life cycle and allow random migrations to occur between patches inhabited by the different populations. We show that if hybridization between different cycle lengths produces offspring that have an intermediate life‐cycle length, then predation acts disproportionately to select against the hybrid offspring. This happens because they emerge in low densities without the safety‐in‐numbers provided by either parent population. Thus, prime‐numbered life cycles that can better avoid hybridization are favored. How…
Hydrothermal origin and age of jadeitites from Sierra del Convento Mélange (Eastern Cuba)
2012
Jadeitite (jadeite jade) from Sierra del Convento (eastern Cuba) occurs in a subduction-related serpentinite-matrix melange associated with a variety of high-pressure tectonic blocks including garnet-amphibolites and related anatectic trondhjemites. The eastern Cuban jadeitite is massive and characterized by rare quartz inclusions and omphacite exsolution in jadeite crystals, as well as replacement or infilling by omphacite. Minor minerals include epidote, biotite, albite, phengite, titanite, rutile, zircon, and apatite. Oscillatory zoning in jadeite crystals and zircon ages suggest hydrothermal crystallization in veins formed in serpentinized peridotite, probably of the mantle wedge. Al-Na…
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…
Survival of two strains of Phthorimaea operculella (Lepidoptera: Gelechiidae) reared on transgenic potatoes expressing a Bacillus thuringiensis cryst…
1998
[Otros] Survie de deux souches de Phthorimaea operculella (Lepidoptera : Gelechiidae) élevées sur des pommes de terre transgéniques exprimant la protéine CrylAb de Bacillus thuringiensis. Deux populations de Phthorimaea operculella (Zeller), l'une supposée résistante au DipelTM (une préparation commerciale de delta-endotoxines de Bacillus thuringiensis) et l'autre sensible, ont été cultivées sur quatre cultivars de pomme de terre, deux transgéniques de première génération, exprimant la protéine CrylAb de Bacillus thuringiensis, et deux non transformés. La population de papillons considérée comme résistante a présenté une mortalité inférieure à celle de l'autre population, mais n'était pas v…
A new gene superfamily of pathogen-response (repat) genes in Lepidoptera: Classification and expression analysis
2012
Repat (REsponse to PAThogens) genes were first identified in the midgut of Spodoptera exigua (Lepidoptera: Noctuidae) in response to Bacillus thuringiensis and baculovirus exposure. Since then, additional repat gene homologs have been identified in different studies. In this study the comprehensive larval transcriptome from S. exigua was analyzed for the presence of novel repat-homolog sequences. These analyses revealed the presence of at least 46 repat genes in S. exigua, establishing a new gene superfamily in this species. Phylogenetic analysis and studies of conserved motifs in these hypothetical proteins have allowed their classification in two main classes, αREPAT and βREPAT. Studies o…
FAMILY PIERIDE (LEPIDOPTERA, PIERIDAE) AND EVOLUTION OVER TIME IN FOREST GROVE SIBIU (SIBIU, ROMANIA)
2015
Transylvania, with its geographic location, flora and fauna is a well defined region, whereby, in addition to many common elements with neighboring areas, there are also some characteristic species, which so far continue to maintain the "endemic" status. The previous decades were very important for the development of Lepidopterological research in Sibiu and Transylvania, in the postwar years. The richness of insect fauna and especially the numerous species of Lepidoptera as of its existing knowledge of this group of insects stimulated the curiosity of many researchers since the middle of the 19th century.
Formation of melanin-based wing patterns is influenced by condition and immune challenge in Pieris brassicae
2005
According to life-history theory, trade-offs emerge because organisms possess a limited amount of resources that they have to allocate between different bodily functions. Here, we tested whether there is a trade-off between melanin-based immune response and dark melanized wing patterning in the large white butterfly, Pieris brassicae L. (Lepidoptera: Pieridae), by activating the immune system of pupae and measuring the wing pigmentation of freshly emerged adults. In contrast to expectations, we did not find any negative associations between immune challenge and wing patterning. Furthermore, implanted and punctured male pupae tended to have larger and darker forewing tips as adults compared …