Search results for "Systematics"
showing 10 items of 6702 documents
Social isolation causes downregulation of immune and stress response genes and behavioural changes in a social insect
2021
Humans and other social mammals experience isolation from their group as stressful, triggering behavioural and physiological anomalies that reduce fitness. While social isolation has been intensely studied in social mammals, it is less clear how social insects, which evolved sociality independently, respond to isolation. Here we examined whether the typical mammalian responses to social isolation, e.g., an impaired ability to interact socially and immune suppression are also found in social insects. We studied the consequences of social isolation on behaviour and brain gene expression in the ant Temnothorax nylanderi. Following isolation, workers interacted moderately less with adult nestma…
Influence of parasitoid-associated viral symbionts on plant–insect interactions and biological control
2021
International audience; Insect parasitoids have evolved symbiotic interactions with several viruses and thousands of parasitoid species have established mutualistic associations with polydnaviruses (PDVs). While PDVs have often been described as virulence factors allowing development of immature parasitoids inside their herbivore hosts, there is increasing awareness that PDVs can affect plant-insect interactions. We review recent literature showing that PDVs alter not only host physiology, but also feeding patterns and composition of herbivore's oral secretions. In turn PDV-induced changes in herbivore phenotype affect plant responses to herbivory with consequences ranging from differential…
Effect of substitutions of key residues on the stability and the insecticidal activity of Vip3Af from Bacillus thuringiensis
2021
Modern agriculture demands for more sustainable agrochemicals to reduce the environmental and health impact. The whole process of the discovery and development of new active substances or control agents is sorely slow and expensive. Vegetative insecticidal proteins (Vip3) from Bacillus thuringiensis are specific toxins against caterpillars with a potential capacity to broaden the range of target pests. Site-directed mutagenesis is one of the most approaches used to test hypotheses on the role of different amino acids on the structure and function of proteins. To gain a better understanding of the role of key amino acid residues of Vip3A proteins, we have generated 12 mutants of the Vip3Af1 …
Secondary metabolites and eco-friendly techniques for agricultural weed/pest management
2021
In agro-ecosystems, pests (insects, weeds, and other plant’s parasites) compete with crops for edaphic resources, negatively affecting quality and crop yields [1]. Nowadays, synthetic pesticides, easy to apply and accessible to farmers, are the most common and effective methods for pest management [2]. Nevertheless, the negative impact of these chemicals on the environment, human health, and the development of herbicides/pesticides-resistance are shifting the attention to alternative pest control technologies based on natural compounds [3–6]. Therefore, new eco-friendly agronomic techniques and the use of natural or natural-like molecules might represent a valid alternative strategy for pes…
Water Deficit Affects the Growth and Leaf Metabolite Composition of Young Loquat Plants
2020
Water scarcity in the Mediterranean area is very common and understanding responses to drought is important for loquat management and production. The objective of this study was to evaluate the effect of drought on the growth and metabolism of loquat. Ninety two-year-old plants of &lsquo
Sugiyamaella mastotermitis sp. nov. and Papiliotrema odontotermitis f.a., sp. nov. from the gut of the termites Mastotermes darwiniensis and Odontote…
2016
Two novel yeast species were isolated from the guts of two different termite species. A new member of the genus Sugiyamaella was isolated from the hindgut and nest material of the lower Australian termite Mastotermes darwiniensis. The second novel yeast species, isolated from the higher termite Odontotermes obesus, was identified as a member of the genus Papiliotrema. Both yeast species were able to hydrolyse xylan, methylumbelliferyl β-xylobiose and methylumbelliferyl β-xylotriose. The ability to debranch different hemicellulose side chains and growth without the addition of external vitamins was observed. A symbiotic role of the novel yeast species is indicated, especially in respect to x…
Evolutionary constraints of warning signals: A genetic trade-off between the efficacy of larval and adult warning coloration can maintain variation i…
2016
To predict evolutionary responses of warning signals under selection, we need to determine the inheritance pattern of the signals, and how they are genetically correlated with other traits contributing to fitness. Furthermore, protective coloration often undergoes remarkable changes within an individual's lifecycle, requiring us to quantify the genetic constraints of adaptive coloration across all the relevant life stages. Based on a 12 generation pedigree with > 11,000 individuals of the wood tiger moth (Arctia plantaginis), we show that high primary defense as a larva (large warning signal) results in weaker defenses as adult (less efficient warning color), due to the negative genetic cor…
Genetic variation in plasticity of life-history traits between Atlantic cod (Gadus morhua) populations exposed to contrasting thermal regimes
2016
We employed common-garden experiments to test for genetic variation in responses of larval life-history traits to temperature between two populations of Atlantic cod (Gadus morhua L., 1758) that naturally experience contrasting thermal environments during early life due to spatial and temporal differences in spawning. Southern Gulf of St. Lawrence cod larvae experienced faster growth in warmer water and low, uniform survival across all experimental temperatures (3, 7, 11 °C), consistent with previous studies on this spring-spawning population. In contrast, larvae from fall-spawning Southwestern Scotian Shelf cod collected near Sambro, Nova Scotia, lacked plasticity for growth but experienc…
The long journey of Orthotrichum shevockii (Orthotrichaceae, Bryopsida): From California to Macaronesia
2019
Biogeography, systematics and taxonomy are complementary scientific disciplines. To understand a species' origin, migration routes, distribution and evolutionary history, it is first necessary to establish its taxonomic boundaries. Here, we use an integrative approach that takes advantage of complementary disciplines to resolve an intriguing scientific question. Populations of an unknown moss found in the Canary Islands (Tenerife Island) resembled two different Californian endemic species: Orthotrichum shevockii and O. kellmanii. To determine whether this moss belongs to either of these species and, if so, to explain its presence on this distant oceanic island, we combined the evaluation of…
Training experiments with Bombus terrestris and Apis mellifera on artificial ‘ Salvia ’ flowers
2016
Abstract Many bee flowers demand physical force from their pollinators. An example is Salvia with lever-like anthers restricting access to nectar. Though the needed force is generally low, it is largely unknown how far even low forces affect flower preference and foraging behaviour of bees. In the present paper, we introduce a method to measure the response of bees to a force mechanism. We explain the construction of artificial flowers mimicking the lever mechanism of a Salvia flower and the procedure to train honeybees and bumblebees to the models. We document the behaviour of the bees on models without barriers and on those with low forces aiming at the same time to determine the bees’ se…