Search results for "INSECT"
showing 10 items of 2033 documents
Myo-inositol as a main metabolite in overwintering flies: seasonal metabolomic profiles and cold stress tolerance in a northern drosophilid fly
2012
SUMMARY Coping with seasonal changes in temperature is an important factor underlying the ability of insects to survive over the harsh winter conditions in the northern temperate zone, and only a few drosophilids have been able to colonize sub-polar habitats. Information on their winter physiology is needed as it may shed light on the adaptive mechanisms of overwintering when compared with abundant data on the thermal physiology of more southern species, such as Drosophila melanogaster. Here we report the first seasonal metabolite analysis in a Drosophila species. We traced changes in the cold tolerance and metabolomic profiles in adult Drosophila montana flies that were exposed to thermope…
Species-specific effects of single sensillum ablation on mating position in Drosophila.
2003
0022-0949 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; Dipteran insects show a wide range of species-specific mating positions. Interspecific transitions from one position to another may reflect sexual or natural selection, or be pleiotropic consequences of other genetic changes. Like many cyclorrhaphan flies, Drosophila species mate with the male on the back of the female, positioned centrally. Mechanosensory sensilla on the male genitalia of three species of the melanogaster species sub-group of Drosophila have species-specific effects on mating position and on courtship success: ablation of a single pair of bristles on the genital claspers of D. melanogaste…
ABCC transporters mediate insect resistance to multiple Bt toxins revealed by bulk segregant analysis
2014
[EN] Background: Relatively recent evidence indicates that ABCC2 transporters play a main role in the mode of action of Bacillus thuringiensis (Bt) Cry1A-type proteins. Mapping of major Cry1A resistance genes has linked resistance to the ABCC2 locus in Heliothis virescens, Plutella xylostella, Trichoplusia ni and Bombyx mori, and mutations in this gene have been found in three of these Bt-resistant strains. Results: We have used a colony of Spodoptera exigua (Xen-R) highly resistant to a Bt commercial bioinsecticide to identify regions in the S. exigua genome containing loci for major resistance genes by using bulk segregant analysis (BSA). Results reveal a region containing three genes fro…
Long-term effects of the trehalase inhibitor trehazolin on trehalase activity in locust flight muscle.
2010
SUMMARY Trehalase (EC 3.2.1.28) hydrolyzes the main haemolymph sugar of insects, trehalose, into the essential cellular substrate glucose. Trehalase in locust flight muscle is bound to membranes that appear in the microsomal fraction upon tissue fractionation, but the exact location in vivo has remained elusive. Trehalase has been proposed to be regulated by a novel type of activity control that is based on the reversible transformation of a latent (inactive) form into an overt (active) form. Most trehalase activity from saline-injected controls was membrane-bound (95%) and comprised an overt form (∼25%) and a latent form (75%). Latent trehalase could be assayed only after the integrity of …
Cost of reproduction in Callosobruchus maculatus: effects of mating on male longevity and the effect of male mating status on female longevity.
2005
One of the most studied life-history trade-offs is that resulting from the cost of reproduction: a trade-off arises when reproduction diverts limited resources from other life-history traits. We examine the cost of reproduction in male, and the effect of male mating status on female Callosobruchus maculatus seed beetles. Cost of reproduction for male C. maculatus was manifested as reduced longevity. There was also a positive relationship between male body size and male longevity. Females mated to males that had already copulated twice did not live as long as females mated to males that had copulated once or not at all. The third copulation of males also lasted longer than the two previous o…
Towards reliable identification of male Dicerura: descriptions of three new and seven poorly known species in the Palearctic region (Diptera: Cecidom…
2018
The taxonomy of Dicerura Kieffer, 1898, a genus of Porricondylinae now comprising 32 species in the Holarctic region, is revised. Three new species are described based on morphological characters of male adults: D. jakovlevi Jaschhof & Spungis sp. nov. (from Finland), D. penttineni Jaschhof & Spungis sp. nov. (Finland), and D. yezoensis Jaschhof & Spungis sp. nov. (Japan). Dicerura padi Mamaev, 1975 syn. nov. is revealed to be a junior synonym of D. furculata Mamaev, 1968. Seven species, whose original descriptions are from a present-day perspective inadequate for the purpose of identification, are redescribed: D. barbata Mamaev, 1966; D. formosa Mamaev, 1998; D. foliicola Mamae…
Helminth communities of two green frogs (Rana perezi and Rana saharica) from both shores of the Alboran Sea.
2006
Les communautes d'helminthes de deux populations de grenouilles vertes des rivages de la mer d'Alboran (mediterraneen occidental) ont ete etudiees. Des 79 grenouilles examinees pour etudier les helminthes, 39 exemplaires de Rana saharica ont ete captures a Bab-Taza (Maroc), et 40 de l'espece Rana perezi dans le Parc Naturel Sierra de Grazalema (Espagne). Bien que la richesse des especes d'helminthes soient identique dans les deux secteurs d'echantillonnage, les differences observees dans la structure des infracommunautes d'helminthes sont assez importantes. Statistiquement, des differences significatives ont ete trouvees entre la richesse en especes et la diversite des infracommunautes chez…
The Drosophila ACP65A cuticle gene: deletion scanning analysis of cis-regulatory sequences and regulation by DHR38.
2005
The regulatory sequences of the Drosophila ACP65A cuticle gene were analyzed in vivo in transgenic flies, using both fusion genes constructs and transposase-mediated deletions within a P element containing ACP65A regulatory sequences fused to the lacZ gene (deletion scanning). The sequences located between −594 and +161 are sufficient to confer both temporal and spatial expression specificities, indicating the presence of tissue-specific enhancers and response elements to hormone-induced factors. In addition, timing of expression and tissue-specificity appear to be controlled by distinct cis-regulatory elements, which suggests the existence of independent hormonal and tissue-specific signal…
Prevention of Tungiasis and Tungiasis-Associated Morbidity Using the Plant-Based Repellent Zanzarin: A Randomized, Controlled Field Study in Rural Ma…
2013
Background Tungiasis, a parasitic skin disease caused by the female sand flea Tunga penetrans, is a prevalent condition in impoverished communities in the tropics. In this setting, the ectoparasitosis is associated with important morbidity. It causes disfigurement and mutilation of the feet. Feasible and effective treatment is not available. So far prevention is the only means to control tungiasis-associated morbidity. Methodology In two villages in Central Madagascar, we assessed the efficacy of the availability of closed shoes and the twice-daily application of a plant-based repellent active against sand fleas (Zanzarin) in comparison to a control group without intervention. The study pop…
Gastro-intestinal symptoms associated with intense Schistosoma mansoni infection affect class-attentiveness of schoolchildren in Ethiopia.
2009
Abstract Objective To assess effect of subtle morbidities related to schistosomiasis mansoni on class-attentiveness of schoolchildren. Methods A cross-sectional study was undertaken involving 568 schoolchildren (mean age 13.4 years; 333 from Schistosoma mansoni endemic villages (Sille and Worke-Mado) and 235 from the non-endemic town Sheno. A questionnaire on signs and symptoms of ill-health was administered to all study subjects. In addition, parasitological and nutritional anthropometric data were collected. All study subjects from S. mansoni endemic areas were treated with praziquantel and albendazol while children from the non-endemic town were only treated with albendazol. Findings Pre…