Search results for "Ivory"
showing 10 items of 132 documents
Impact of parasitoid-associated polydnaviruses on plant-mediated herbivore interactions
2022
Insect herbivores interact via plant-mediated interactions in which one herbivore species induces changes in plant quality that affects the performance of a second phytophagous insect that shares the food plant. These interactions are often asymmetric due to specificity in induced plant responses to herbivore attack, amount of plant damage, elicitors in herbivore saliva and plant organ damaged by herbivores. Parasitoids and their symbiotic polydnaviruses alter herbivore physiology and behaviour and may influence how plants respond to parasitized herbivores. We argue that these phenomena affect plant-mediated interactions between herbivores. We identify that the extended phenotype of parasit…
Mutualistic tree-frugivore interactions in Afrotropical forests : from local ecological knowledge to the identification of network interaction patter…
2022
Frugivory in tropical forests is a major ecological process, as most tree species rely on frugivores for their dispersion, and numerous animal species used fruits as their principal sources of food. However, frugivory networks between plants and animals in Afrotropical forests are poorly described, and the mechanisms shaping them remain largely unexplored. This PhD thesis addresses a structural approach of the frugivory network, a plant-community approach and a methodological approach using local ecological knowledge and cameras.The first chapter describes the frugivory network of Afrotropical forests, based on a compilation of frugivory interactions from the literature that comprised >10,0…
Sensory biology of Phalangida harvestmen (Arachnida, Opiliones): a review, with new morphological data on 18 species
2009
1463-6395 10.1111/j.1463-6395.2008.00341.x; Willemart, R. H., Farine, J.-P. and Gnaspini, P. 2008. Sensory biology of Phalangida harvestmen (Arachnida, Opiliones): a review, with new morphological data on 18 species. 2014Acta Zoologica (Stockholm) 90: 2092013227 Phalangida includes three of the four suborders of Opiliones (Arachnida): Eupnoi, Dyspnoi and Laniatores. We review the literature on the sensory structures and capabilities of Phalangida, provide new morphological data for 18 species and discuss the 11 sensory structures that have been described in the group. Based on the published data encompassing both behaviour and morphology, three conclusions are apparent: (1) species of Phala…
Glyphosate-based herbicide has soil-mediated effects on potato glycoalkaloids and oxidative status of a potato pest
2020
Glyphosate is the most used herbicide worldwide, targeting physiological pathways in plants. Recent studies have shown that glyphosate can also cause toxic effects in animals. We investigated the glyphosate-based herbicide (GBH)-induced changes in potato (Solanum tuberosum) plant chemistry and the effects of a GBH on the survival rate and oxidative status of the Colorado potato beetle (Leptinotarsa decemlineata). The beetles were reared on potato plants grown in pots containing soil treated with a GBH (Roundup Gold, 450 g/l) or untreated soil (water control). The 2nd instar larvae were introduced to the potato plants and then collected in 2 phases: as 4th instar larvae and as adults. The ma…
Combining Hexanoic Acid Plant Priming with Bacillus thuringiensis Insecticidal Activity against Colorado Potato Beetle
2013
Interaction between insect herbivores and host plants can be modulated by endogenous and exogenous compounds present in the source of food and might be successfully exploited in Colorado potato beetle (CPB) pest management. Feeding tests with CPB larvae reared on three solanaceous plants (potato, eggplant and tomato) resulted in variable larval growth rates and differential susceptibility to Bacillus thuringiensis Cry3Aa toxin as a function of the host plant. An inverse correlation with toxicity was observed in Cry3Aa proteolytic patterns generated by CPB midgut brush-border membrane vesicles (BBMV) from Solanaceae-fed larvae, being the toxin most extensively proteolyzed on potato, followed…
Can herbivore-induced volatiles protect plants by increasing the herbivores’ susceptibility to natural pathogens?
2018
In response to insect herbivory, plants mobilize various defenses. Defense responses include the release of herbivore-induced plant volatiles (HIPVs) that can serve as signals to alert undamaged tissues and to attract natural enemies of the herbivores. Some HIPVs can have a direct negative impact on herbivore survival, but it is not well understood by what mechanisms. Here, we tested the hypothesis that exposure to HIPVs renders insects more susceptible to natural pathogens. Exposure of the caterpillars of the noctuid Spodoptera exigua to indole and linalool, but not exposure to (Z)-3-hexenyl acetate, increased the susceptibility to Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV). …
Essential oil of Cyphostemma juttae (Vitaceae): Chemical composition and antitumor mechanism in triple negative breast cancer cells
2019
The genus Cyphostemma (Planch.) Alston (Vitaceae) includes about 150 species distrib- uted in eastern and southern Africa and Madagascar. Some species are used in traditional medicine and their biological activities, including antiproliferative effects against cancer cell lines, have been demonstrated. To date no investigations on Cyphostemma essential oils have been carried out. Essential oils, which play important roles in plant defenses have been demonstrated to be active in the treatment of several human diseases and to enhance bioavability of other drugs. The aim of this paper was to identify the chemical composition of the essential oil of the leaves of Cyphostemma juttae (Dinter &…
Imprints of latitude, host taxon, and decay stage on fungus-associated arthropod communities
2022
Interactions among fungi and insects involve hundreds of thousands of species. While insect communities on plants have formed some of the classic model systems in ecology, fungus-based communities and the forces structuring them remain poorly studied by comparison. We characterize the arthropod communities associated with fruiting bodies of eight mycorrhizal basidiomycete fungus species from three different orders along a 1200-km latitudinal gradient in northern Europe. We hypothesized that, matching the pattern seen for most insect taxa on plants, we would observe a general decrease in fungal-associated species with latitude. Against this backdrop, we expected local communities to be struc…
The ecomorphology of southern African rodent incisors: Potential applications to the hominin fossil record.
2018
AbstractThe taxonomic identification of mammalian fauna within fossil assemblages is a well-established component of paleoenvironmental reconstructions. However, many fragmentary specimens recovered from fossil sites are often disregarded as they can be difficult to identify with the precision required for taxonomic methods. For this reason, the large numbers of isolated rodent incisors that are often recovered from hominin fossil bearing sites have generally been seen as offering little interpretive value. Ecomorphological analysis, often referred to as a “taxon-free” method, can potentially circumvent this problem by focusing on the adaptive, rather than the taxonomic significance of rode…
Dental calculus evidence of Taï Forest Chimpanzee plant consumption and life history transitions
2015
AbstractDental calculus (calcified dental plaque) is a source of multiple types of data on life history. Recent research has targeted the plant microremains preserved in this mineralised deposit as a source of dietary and health information for recent and past populations. However, it is unclear to what extent we can interpret behaviour from microremains. Few studies to date have directly compared the microremain record from dental calculus to dietary records and none with long-term observation dietary records, thus limiting how we can interpret diet, food acquisition and behaviour. Here we present a high-resolution analysis of calculus microremains from wild chimpanzees (Pan troglodytes ve…