Search results for "LEPIDOPTERA"
showing 10 items of 191 documents
Evaluation of criteria for species delimitation of bagworm moths (Lepidoptera: Psychidae)
2014
Accurate identification of species is fundamental for biological research and necessary for species conservation. DNA bar- coding is particularly useful when identification using morphological characteristics is laborious and/or unreliable. However, bar- codes for species are dependent on the availability of reference sequences from correctly identified specimens. The traditional use of morphology to delimit the species boundaries of Finnish bagworm moths (Lepidoptera: Psychidae: Naryciinae: Dahliciini) is contro- versial because there is overlap in their morphological characteristics. In addition, there are no suitable molecular markers. We veri- fied the delimitation of seven out of eight…
The crystal structure of a 250-kDa heterotetrameric particle explains inhibition of sheddase meprin β by endogenous fetuin-B
2021
Meprin β (Mβ) is a multidomain type-I membrane metallopeptidase that sheds membrane-anchored substrates, releasing their soluble forms. Fetuin-B (FB) is its only known endogenous protein inhibitor. Herein, we analyzed the interaction between the ectodomain of Mβ (MβΔC) and FB, which stabilizes the enzyme and inhibits it with subnanomolar affinity. The MβΔC:FB crystal structure reveals a ∼250-kDa, ∼160-Å polyglycosylated heterotetrameric particle with a remarkable glycan structure. Two FB moieties insert like wedges through a “CPDCP trunk” and two hairpins into the respective peptidase catalytic domains, blocking the catalytic zinc ions through an “aspartate switch” mechanism. Uniquely, the …
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)
Gluing the ‘unwettable’: soil-dwelling harvestmen use viscoelastic fluids for capturing springtails
2014
Gluing can be a highly efficient mechanism of prey capture, as it should require less complex sensory–muscular feedback. Whereas it is well known in insects, this mechanism is much less studied in arachnids, except spiders. Soil-dwelling harvestmen (Opiliones, Nemastomatidae) bear drumstick-like glandular hairs (clavate setae) at their pedipalps, which were previously hypothesized to be sticky and used in prey capture. However, clear evidence for this was lacking to date. Using high-speed videography, we found that the harvestman Mitostoma chrysomelas was able to capture fast-moving springtails (Collembola) just by a slight touch of the pedipalp. Adhesion of single clavate setae increased p…
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…
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…
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…