Search results for "Pollinator"
showing 10 items of 95 documents
The Floral Nectaries of the Geraniales and their Systematic Implications.
1992
Summary In the monogeneric family Ctenolophonaceae extrastaminal discs are developed, whose parenchyma and marginally stomata bearing epidermis appear to be adenoid. The discs are extensively vascularized by phloematic branches derived from bundles of the adnate stamens. The flowers are unshowy, simply constructed and without special nectar protecting structures. Pollinators are still unknwon, but nectar-exploiting bees and flies probably predominate. The Ctenolophonaceae are closely connected with Humiriaceae. Presumed affinities with Malpighiaceae are questioned.
Preliminary identification of self-incompatibility genotypes of Sicilian almond landraces
2018
Sicily is the main almond producer in Italy. The almond tree is one of the main protagonists of the Sicilian agrarian landscape, especially in the winter, when the bare branches are covered by white or pinkish flowers. Its presence is particularly significant in the province of Agrigento, in Syracuse and in Ragusa areas, where the almond nut is used for fresh consumption and for the preparation of typical sweets. The extremely rich Sicilian almond germplasm can be useful for genetic improvement, since many local landraces possess aromatic characteristics of the nuts of high value. Self-incompatibility in this species is gametophytic and controlled by a multi-allelic S locus, coding for the …
Host plant and arbuscular mycorrhizal fungi show contrasting responses to temperature increase: Implications for dioecious plants
2014
Individual plants live in complex environments where they interact with other organisms such as herbivores, pollinators, fungi and pathogens. The influence of rising temperature on biotic interactions has begun to receive attention, and is an important research frontier currently. However, the belowground interactions with organisms such as arbuscular mycorrhizal (AM) fungi have received little attention so far. In this study, we investigated the response of the dioecious plant Antennaria dioica and its AM fungi to increased temperature in a controlled environment simulating the period of growth of A. dioica in central Finland. Specifically, we evaluated the effect of rising temperature on …
High Temperatures Result in Smaller Nurseries which Lower Reproduction of Pollinators and Parasites in a Brood Site Pollination Mutualism
2014
In a nursery pollination mutualism, we asked whether environmental factors affected reproduction of mutualistic pollinators, non-mutualistic parasites and seed production via seasonal changes in plant traits such as inflorescence size and within-tree reproductive phenology. We examined seasonal variation in reproduction in Ficus racemosa community members that utilise enclosed inflorescences called syconia as nurseries. Temperature, relative humidity and rainfall defined four seasons: winter; hot days, cold nights; summer and wet seasons. Syconium volumes were highest in winter and lowest in summer, and affected syconium contents positively across all seasons. Greater transpiration from the…
Effects of landscape composition on hoverflies (Diptera: Syrphidae) in mass-flowering crop fields within forest-dominated landscapes
2022
Agricultural intensification has led to structurally simplified landscapes with reduced and fragmented resources for farmland insects. However, studies on the effects of landscape composition on farmland insects have mainly been performed in areas dominated by open arable land and semi-natural grasslands, while studies from forest-dominated landscapes are scarce. This research examined the effects of landscape composition on hoverfly species richness and abundance in arable land in boreal forest-dominated landscapes. Hoverflies were sampled in 22 mass-flowering caraway (Carum carvi) fields in Central Finland using pan traps. The effects of landscape composition on species richness and abund…
IPM-recommended insecticides harm beneficial insects through contaminated honeydew
2020
The use of some systemic insecticides has been banned in Europe because they are toxic to beneficial insects when these feed on nectar. A recent study shows that systemic insecticides can also kill beneficial insects when they feed on honeydew. Honeydew is the sugar-rich excretion of hemipterans and is the most abundant carbohydrate source for beneficial insects such as pollinators and biological control agents in agroecosystems. Here, we investigated whether the toxicity of contaminated honeydew depends on i) the hemipteran species that excretes the honeydew; ii) the active ingredient, and iii) the beneficial insect that feeds on it. HPLC-MS/MS analyses demonstrated that the systemic insec…
The staminal lever mechanism in Salvia L. (Lamiaceae): a key innovation for adaptive radiation?
2004
Abstract Floral key innovations play a significant role in the discussion of adaptive radiation in plants. The paper brings together a brief review of morphological key innovations in plants, elucidating their evolutionary significance in flower–pollinator interactions, and new data on Salvia, a genus being examined as an example for presumed adaptive radiation. We hypothesize that the characteristic staminal lever mechanism functions as a key innovation. It is defined as a functional unit including the modification of stamens to lever-like structures, their reversible movement, and the organization of the remaining floral structures involved in the process of pollen transfer. We follow the…
New Insights into the Functional Morphology of the Lever Mechanism of Salvia pratensis (Lamiaceae)
2007
† Background and Aims The functional morphology of Salvia pratensis flowers was re-investigated, after new insights revealed that pollen dispensing is one of the main functions of the staminal lever. In particular, no detailed information was available regarding the process of pollen transfer and the forces arising between the pollen-bearing thecae and the pollinating bee’s body. The assumption was made that these forces play a significant role in pollen dispensing. † Methods The functional morphology of S. pratensis flowers and the interaction between flowers and bees (Apis mellifera) were studied by reconstructing stress and strains by using qualitative and semi-quantitative theoretical a…
Abeilles et plantes cultivées en Espagne : actualisation des données pour le melon, la pastèque et l’amandier
2021
[EN] Pollinators of most of the plants cultivated in the Mediterranean regions of Europe are still unknown. We provide new data and we review previously available information on bees (Apoidea) associated with three economically important crops in Spain: melon (Cucumis melo L.), watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) and almond (Prunus dulcis (Mill.) D.A.Webb). We found that, overall, 98 bee species spanning four families visit flowers of the studied crop species, and 46 additional species were sampled within the crops with pan-traps. The bee assemblages visiting melon include 7–33 species, with moderate to high importance of small Lasioglossum (Halictidae) and of honey bee …
Sex-specific interaction between arbuscular mycorrhizal and dark septate fungi in the dioecious plant Antennaria dioica (Asteraceae).
2012
Male and female plants of dioecious species often differ in their resource demands and this has been linked to secondary sexual dimorphism, including sex-specific interactions with other organisms such as herbivores and pollinators. However, little is known about the interaction between dioecious plants and fungal root endophytes. Plants may be simultaneously colonised by arbuscular mycorrhizal (AM) and dark septate (DS) fungi. While it is well established that AM mutualism involves reciprocal transfer of photosynthates and mineral nutrients between roots of host plants and these fungi, the role of DS fungi remains controversial. Here, we report the temporal and spatial variation in AM and …