Search results for "ENTO"
showing 10 items of 11102 documents
Chemistry of defensive secretions in nymphs and adults of fire bug , Pyrrhocoris apterus L.(Heteroptera, Pyrrhocoridae)
1992
International audience; The defensive secretions from the nymphs and the adults of both sexes in P. apterus were chemically investigated. Forty components were identified from the nymphal posterior dorsoabdominal glands and 35 from the adult metathoracic glands of both sexes. Within the 43 identified chemicals, we found 23 aldehydes, five saturated hydrocarbons, five alcohols, three ketones, three lactones, two terpenes, one phenol and one ester. Thirteen of these compounds had never been reported within the Heteroptera. Whereas eight components are specific to the nymphs, methyl pentenal, (E)-2-hexenol, and heptadecanal are the only adult-specific components. The biological role of all the…
The concept of genus within the family Phytoseiidae (Acari: Parasitiformes): historical review and phylogenetic analyses of the genus Neoseiulus Hugh…
2012
Systematic studies on the family Phytoseiidae were first conducted at the beginning of the 20th century but increased greatly after the Second World War. Various classifications have been proposed based on different characters such as: dorsal, ventral, and leg chaetotaxy; the shape of ventrianal and sternal shields; the shape of the insemination apparatus (spermatheca) and spermatodactylus; the number of teeth on the movable digit of chelicera; and dorsal and ventral adenotaxy. The genus concepts developed over the last five decades can be divided into two main categories or hypotheses. The first, supported mainly by Chant and McMurtry, focuses on dorsal and ventral chaetotaxy, and the gene…
New taxa of Orthoptera (Insecta Tettigoniidae Phaneropterinae) from Madagascar.
2017
The author reports the results of a study on Orthoptera collected in Madagascar and preserved in two European Natural History museums. He describes Symmetroraggea depravata n. sp., Parapyrrhicia longipodex n. sp., Madagascarantia bartolozzii n. gen. n. sp., Mimoscudderia spinicercata n. sp. In addition, he lists new records or unknown taxonomical characters of Xenodus nobilis Carl, 1914 and Parapyrrhicia virilis Carl, 1914.
Prohexadione calcium is herbicidal to the sunflower root parasite Orobanche cumana
2020
BACKGROUND The obligatory sunflower root parasite Orobanche cumana Wallr. deprives its host of essential nutrients, resulting in a dramatic reduction in yield and biomass. A post-emergence application with an imidazolinone herbicide on an imidazolinone-tolerant sunflower is highly effective against O. cumana. The herbicide inhibits the enzyme acetohydroxy acid synthase and consequently, growth of the parasite is inhibited, although the sunflower survives the treatment through mutations in the target enzyme. Interestingly, field studies have shown that a combined application of an imidazolinone herbicide with prohexadione resulted in reduced emergence of O. cumana compared with the sole appl…
Chlamyphilone, a Novel Pochonia chlamydosporia Metabolite with Insecticidal Activity
2019
Metabolites from a collection of selected fungal isolates have been screened for insecticidal activity against the aphid Acyrthosiphon pisum. Crude organic extracts of culture filtrates from six fungal isolates (Paecilomyces lilacinus, Pochonia chlamydosporia, Penicillium griseofulvum, Beauveria bassiana, Metarhizium anisopliae and Talaromyces pinophilus) caused mortality of aphids within 72 h after treatment. In this work, bioassay-guided fractionation has been used to characterize the main bioactive metabolites accumulated in fungal extracts. Leucinostatins A, B and D represent the bioactive compounds produced by P. lilacinus. From P. griseofulvum and B. bassiana extracts, griseofulvin an…
Colour gene allele frequencies correlated with altitude of habitat in Philaenus populations
2009
Colour morph frequencies were investigated in samples from 15 Philaenus spumarius populations in the western parts of Byelorussia and Ukraine. The three main results of the study are the following: (1) In many populations, breakdown of the barrier inhibiting penetrance of colour allele expression in the male sex, (2) unexpected absence of the allele ppra (for colour morph praeustus) in Ukraine, and (3) an apparent positive correlation between altitude of habitat and the frequency of the allele pO (for colour morphs quadrimaculatus, albomaculatus and leucophthalmus). Some indications of a similar positive correlation between altitude and pO frequency were noted in 1966 in populations living …
Collisional mechanism of ligand release by Bombyx mori JHBP, a member of the TULIP / Takeout family of lipid transporters.
2020
International audience; Juvenile hormones (JHs) regulate important processes in insects, such as postembryonic development and reproduction. In the hemolymph of Lepidoptera, these lipophilic sesquiterpenic hormones are transported from their site of synthesis to target tissues by high affinity carriers, the juvenile hormone binding proteins (JHBPs). Lepidopteran JHBPs belong to a recently uncovered, yet very ancient family of proteins sharing a common lipid fold (TULIP domain) and involved in shuttling various lipid ligands. One important, but poorly understood aspect of JHs action, is the mechanism of hormone transfer to or through the plasma membranes of target cells. Since many membrane-…
RNA interference in Lepidoptera: an overview of successful and unsuccessful studies and implications for experimental design.
2011
International audience; Gene silencing through RNA interference (RNAi) has revolutionized the study of gene function, particularly in non-model insects. However, in Lepidoptera (moths and butterflies) RNAi has many times proven to be difficult to achieve. Most of the negative results have been anecdotal and the positive experiments have not been collected in such a way that they are possible to analyze. In this review, we have collected detailed data from more than 150 experiments including all to date published and many unpublished experiments. Despite a large variation in the data, trends that are found are that RNAi is particularly successful in the family Saturniidae and in genes involv…
New records of phytoseiid mites from Italy, with description of a new species and a redescription of other two (Parasitiformes, Phytoseiidae)
2020
The Italian phytoseiid fauna consists of 91 valid species. Eighteen of them were described as new species from materials collected in various Italian localities. In the present paper we report nine new records from the Italian fauna and describe the new species, Neoseiulus mediterraneus belonging to the subfamily Amblyseiinae. Complementary descriptions of two rare species, namely: Typhlodromus (Anthoseius) singularis and Typhlodromus (Typhlodromus) knisleyi, were also added.
Tomato trichomes are deadly hurdles limiting the establishment of Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae)
2021
[EN] Amblyseius swirskii is a predatory mite widely used for the control of very important pest species, such as whiteflies and thrips, in organic farming and conventional agriculture. However, this species cannot establish on tomato crops, probably due to the toxic effects of plant trichomes and their exudates. We evaluated tomato plants for effects on: a) A. swirskii preference mediated by plant volatiles, b) A. swirskii development, predation capacity and reproductive performance, c) the dispersal and survival of mites as affected by stem trichomes, and d) mite survival as a function of secondary metabolites secreted by tomato trichomes. The results showed that A. swirskii mites which ga…