Search results for "Han"
showing 10 items of 32320 documents
Revision of the tropical African genus Tetraconcha (Orthoptera: Tettigoniidae: Phaneropterinae) with the description of ten new species.
2017
Only five species of the genus Tetraconcha Karsch, 1890 have been previously known; they inhabit tropical forests of central and western Africa. Generally, specimens belonging to this genus are scarcely represented in museum collections, probably due to the difficulty in finding them, but also for the fragility of their body and legs. During some recent expeditions in the Central African Republic and Ivory Coast it was possible to put together an abundant amount of specimens. This allowed the present author to revise the genus and to find valid characters to distinguish different species. On the whole, ten new species were discovered and the total number now amounts to fifteen species. Inte…
High-speed duetting-latency times of the female acoustic response within the bush-cricket genera Leptophyes and Andreiniimon (Orthoptera, Phaneropter…
2018
To find a mate, male and female bush-crickets of the family Phaneropteridae typically engage in duets. The male sings and the female responds. For mutual recognition, the amplitude pattern of the male song and the species-specific timing of the female response have been shown to be very important. In the seven studied species, belonging to the generaLeptophyesandAndreiniimon, these duets are extremely fast and nearly completely in the ultrasonic range. The females produce very short sounds by fast closing movements of the tegmina. They respond with species-specific delays of 20 to 150 ms after the beginning of the male song. The different latency times are probably not important for species…
Mutations associated with pyrethroid resistance in Varroa mite, a parasite of honey bees, are widespread across the United States.
2021
BACKGROUND Managed honey bees are key pollinators of many crops and play an essential role in the United States food production. For more than ten years, beekeepers in the United States have been reporting high rates of colony losses. One of the drivers of these losses is the parasitic mite Varroa destructor. Maintaining healthy honey bee colonies in the United States is dependent on a successful control of this mite. The pyrethroid tau-fluvalinate (Apistan®) was among the first synthetic varroacides registered in the United States. With over 20 years of use, mites resistant to Apistan® have emerged, and so it is unsurprising that treatment failures have been reported. Resistance to tau-flu…
Pest management under climate change: The importance of understanding tritrophic relations.
2018
11 pages; International audience; Plants and insects depend on climatic factors (temperature, solar radiation, precipitations, relative humidity and CO2) for their development. Current knowledge suggests that climate change can alter plants and insects development and affect their interactions. Shifts in tritrophic relations are of particular concern for Integrated Pest Management (IPM), because responses at the highest trophic level (natural enemies) are highly sensitive to warmer temperature. It is expected that natural enemies could benefit from better conditions for their development in northern latitudes and IPM could be facilitated by a longer period of overlap. This may not be the ca…
Ultrastructure of regions containing homologous loci in polytene chromosomes of Drosophila melanogaster and Drosophila subobscura.
1998
We have used a new approach involving in situ hybridisation and electron microscopy to establish ultrastructural homologies between polytene chromosome regions of Drosophila melanogaster and Drosophila subobscura. Twelve probes were chosen to cover all the chromosomal elements: the myospheroid gene, the collagen type IV gene, the collagen-like gene, the w26 homeobox gene, the beta3 tubulin gene, the kinesin heavy chain gene, the tryptophan hydrolase gene, the Hsp82, Hsp22-26 and Hsp23-28, Hsp68, Hsp70 genes and the beta unit of the F0-F1 ATPase gene. Most of these loci were previously undescribed in D. subobscura and imprecisely located in D. melanogaster. We have demonstrated here, by an u…
Validation of an online system for the continuous monitoring of tree water status for sustainable irrigation managements in olive (Olea europaea L.)
2016
Abstract As a result of climate change a large reduction of agricultural water through improved irrigation management is a major need for agriculture sustainability. To this aim, always more sensitive sensors to monitor plant water status have been developed in recent years. Among them, the leaf patch clamp pressure probes are very promising for water management of olive but until now have been tested only in few environmental and management conditions. In this work these sensors have been tested for two consecutive years on two completely different management systems: a traditional rainfed orchard and a super high density (SHD) drip irrigated orchard. Within the SHD orchard the probes have…
Risk of inbreeding : problem of mate choice and fitness effects?
2016
Mating with close kin may cause inbreeding depression with negative consequences to offspring and local populations. There exist mechanisms like kin-recognition or sex-specific dispersal to avoid mating with kin. In fluctuating population densities, like in many small mammals, both very low and very high densities provide conditions for inbreeding, if kin males are prone to stay in their natal area. Females are choosy and male dominance is thought to be the key feature when selecting mating partners. The aim of this study was to test the possible discrepancy in mate choice and negative fitness effects of inbreeding in two experiments, one in the laboratory and one in field enclosures. We as…
Use of Kluyveromyces marxianus to Increase Free Monoterpenes and Aliphatic Esters in White Wines
2021
An increasing interest in novel wine productions is focused on non-Saccharomyces yeasts due to their potential in improving sensory profiles. Although Kluyveromyces marxianus has been originally isolated from grapes and its enzymatic activities are used in oenology, rarely it has been used as co-starter. The K. marxianus Km L2009 strain has been characterized here and selected as a co-starter both at laboratory- and winery-scale fermentation. The Km L2009 strain showed growth of up to 40 (mg/L) of sulfites and 6% (v/v) of ethanol. Gas chromatographic analysis demonstrates that wines produced by mixed fermentation contain remarkably higher quantities of free monoterpenes and aliphatic esters…
Biodiversity change after climate-induced ice-shelf collapse in the Antarctic
2011
Julian Gutt ... et al. -- 10 pages, 5 figures, 1 table, supplementary data https://doi.org/10.1016/j.dsr2.2010.05.024
A Visitor of Tropical Waters: First Record of a Clymene Dolphin (Stenella clymene) Off the Patagonian Coast of Argentina, With Comments on Diet and M…
2021
The poorly known Clymene dolphin (Stenella clymene) is a small oceanic cetacean distributed in tropical and subtropical waters of the Atlantic Ocean. In this study, we report, for the first time, a vagrant individual of Clymene dolphin in Argentina (Rada Tilly) that represents the current southern-most record for this cetacean species. We provide a molecular identification of the dolphin, based on partial sequences of the mitochondrial cytochrome b gene, generated from DNA extracted from its metazoan parasites. Three prey species, namely Argentine hake, Patagonian squid and lobster krill were identified from hard pieces collected in the stomach. Seven metazoan parasite taxa (three in adult …