Search results for "je"
showing 10 items of 44818 documents
Experimental increase in fecundity causes upregulation of fecundity and body maintenance genes in the fat body of ant queens.
2021
In most organisms, fecundity and longevity are negatively associated and the molecular regulation of these two life-history traits is highly interconnected. In addition, nutrient intake often has opposing effects on lifespan and reproduction. In contrast to solitary insects, the main reproductive individual of social hymenopterans, the queen, is also the most long-lived. During development, queen larvae are well-nourished, but we are only beginning to understand the impact of nutrition on the queens' adult life and the molecular regulation and connectivity of fecundity and longevity. Here, we used two experimental manipulations to alter queen fecundity in the ant Temnothorax rugatulus and …
Assessing larval food quality for phytophagous insects: are the facts as simple as they appear?
2006
9 pages; International audience; We argue here that host plant quality affects many life-history traits of herbivorous insects and these traits often interact. Studies that look only at a limited number of traits often fail to determine the overall effect of plant quality on larval performance and adult fitness. Parameters such as mating success and adult longevity are frequently neglected even though they are affected by larval feeding and are crucial to overall fitness. To illustrate this, we examined a whole suite of life-history traits of the moth Lobesia botrana after rearing larvae of this grape pest on three different grape cultivars. Development time, mating success, fecundity, egg …
The past and the present in decision-making: the use of conspecific and heterospecific cues in nest site selection
2014
International audience; Nest site selection significantly affects fitness, so adaptations for assessment of the qualities of available sites are expected. The assessment may be based on personal or social information, the latter referring to the observed location and performance of both conspecific and heterospecific individuals. Contrary to large-scale breeding habitat selection, small-scale nest site selection within habitat patches is insufficiently understood. We analyzed nest site selection in the migratory Collared Flycatcher Ficedula albicollis in relation to present and past cues provided by conspecifics and by resident tits within habitat patches by using long-term data. Collared F…
Coping styles in farmed fish: consequences for aquaculture
2017
Individual differences in physiological and behavioural responses to stressors are increasingly recognised as adaptive variation and thus raw material for evolution and fish farming improvements including selective breeding. Such individual variation has been evolutionarily conserved and is present in all vertebrate taxa including fish. In farmed animals, the interest in consistent trait associations, that is coping styles, has increased dramatically over the last years because many studies have demonstrated links to performance traits, health and disease susceptibility and welfare. This study will review (i) the main behavioural, neuroendocrine, cognitive and emotional differences between …
Dimensions of invasiveness: Links between local abundance, geographic range size, and habitat breadth in Europe's alien and native floras.
2021
Understanding drivers of success for alien species can inform on potential future invasions. Recent conceptual advances highlight that species may achieve invasiveness via performance along at least three distinct dimensions: 1) local abundance, 2) geographic range size, and 3) habitat breadth in naturalized distributions. Associations among these dimensions and the factors that determine success in each have yet to be assessed at large geographic scales. Here, we combine data from over one million vegetation plots covering the extent of Europe and its habitat diversity with databases on species' distributions, traits, and historical origins to provide a comprehensive assessment of invasive…
Symmetry breaking in mass-recruiting ants: extent of foraging biases depends on resource quality.
2016
Abstract The communication involved in the foraging behaviour of social insects is integral to their success. Many ant species use trail pheromones to make decisions about where to forage. The strong positive feedback caused by the trail pheromone is thought to create a decision between two or more options. When the two options are of identical quality, this is known as symmetry breaking, and is important because it helps colonies to monopolise food sources in a competitive environment. Symmetry breaking is thought to increase with the quantity of pheromone deposited by ants, but empirical studies exploring the factors affecting symmetry breaking are limited. Here, we tested if (i) greater …
Guidelines for risk management in forest planning – what is risk and when is risk management useful?
2018
Managing forest resources occurs under various sources of uncertainty. Depending on the management problem, this uncertainty may have a substantial impact on the quality of the solution. As our knowledge on the sources and magnitude of uncertainty improves, integrating this knowledge into the development of management plans becomes increasingly useful, as additional information can improve the decision-making process. This adjustment requires a fundamental shift in how planning problems are viewed: instead of interpreting risk management as a technique needed only for addressing problems with natural hazards, risk management should be an integral part of most planning problems. Managing ri…
Value of information in multiple criteria decision making: an application to forest conservation
2019
Abstract Developing environmental conservation plans involves assessing trade-offs between the benefits and costs of conservation. The benefits of conservation can be established with ecological inventories or estimated based on previously collected information. Conducting ecological inventories can be costly, and the additional information may not justify these costs. To clarify the value of these inventories, we investigate the multiple criteria value of information associated with the acquisition of improved ecological data. This information can be useful when informing the decision maker to acquire better information. We extend the concept of the value of information to a multiple crite…
Potential of using data assimilation to support forest planning
2017
Uncertainty in forest information typically results in economic and ecological losses as a consequence of suboptimal management decisions. Several techniques have been proposed to handle such uncertainties. However, these techniques are often complex and costly. Data assimilation (DA) has recently been advocated as a tool that may reduce the uncertainty, thereby improving the quality of forest planning results. It offers an opportunity to make use of all new sources of information in a systematic way and thus provides more accurate and up-to-date information to forest planning. In this study, we refer to literature on handling uncertainties in forest planning, as well as related literature…
High within- and between-trunk variation in the nematoceran (Diptera) community and its physical environment in decaying aspen trunks
2012
Dead wood is a primary habitat for a large number of insects, including species from many nematoceran (Diptera) groups. The species living in dead wood must be adapted to the ephemeral and ever-changing nature of their substrate. There is a growing body of knowledge about the effects of dead wood quality and the surrounding landscape on the saproxylic beetle community, but we know very little about the other saproxylic insects. Moreover, we know only very little about the variation in the insect community between different parts of decaying wood pieces. Using emergence traps, we studied the saproxylic nematoceran communities occupying different parts of decaying fallen aspen trunks in a bor…