ABSTRACT
Specialized pollination systems frequently match a particular set of floral characteristics. Vincetoxicum spp. (Apocynaceae, Asclepiadoideae) have disk‐shaped flowers with open access to ...rewards and reproductive organs. Flowers with these traits are usually associated with generalized pollination. However, the highly modified androecium and gynoecium that characterize asclepiads are thought to be associated with specialized pollinators.
In V. sangyojarniae, we investigated floral biology, pollination, and the degree of pollinator specialization in two localities in Thailand. We examined floral traits that target legitimate pollinators.
Flowers of V. sangyojarniae opened only at night, emitted floral scents containing mainly (E)‐β‐ocimene, 1‐octen‐3‐ol, (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (E‐DMNT) and N‐(3‐methylbutyl)acetamide, and provided sucrose‐dominated nectar openly to insect visitors. Assessment of pollinator effectiveness indicated that V. sangyojarniae is functionally specialized for pollination by cecidomyiid flies. Although various insects, particularly cockroaches, frequently visited flowers, they did not carry pollinaria.
Our results suggest that V. sangyojarniae attracts its fly pollinators by emitting floral volatiles bearing olfactory notes associated with the presence of fungi or, less likely, of prey captured by predatory arthropods (food sources of its pollinators) but offers a nectar reward upon insect arrival. Hence, there is a mismatch between the advertisement and the actual reward. Our results also suggest that the size of floral parts constitutes a mechanical filter where reciprocal fit between flower and insect structures ensures that only suitable pollinators can extract the pollinaria, a prerequisite for successful pollination.
Vincetoxicum sangyojarniae combines nectar reward with food deception to attract its pollinators and ensures successful pollination through reciprocal mechanical fit between plant reproductive organs and insect structures.
Respiratory diseases represent a major public health issue and impact both quality of life and life expectancy of the patients.
Several interventions used in respiratory physiotherapy have been shown ...to reduce dyspnoea, improve quality of life and reduce hospitalisation in many respiratory diseases. However, respiratory physiotherapy remains poorly known to the medical community and may be under-prescribed.
In order to improve the interdisciplinarity around the patient with respiratory impairment, we describe the interests and prescription modalities of liberal respiratory physiotherapy. In the context of respiratory physiotherapy acts, the precision of drafting prescription directly conditions the means implemented by the physiotherapist regarding care provided to the patient.
The increased knowledge of prescribers, both concerning the prescription methods and the precise content of the rehabilitation sessions is one of the keys to their success.
The Mediterranean fig (
Ficus carica)
is dioecious, with distinct male and female trees. Its pollinator,
Blastophaga psenes
, is hosted within male figs. We studied caprification, a practice to ...facilitate pollination by placing male figs from which pollinators emerge in female trees, among Jbala farmers in Morocco to analyze (1) farmers’ knowledge of the pollinator’s life cycle and receptivity of female figs; (2) the distribution of female fig varieties and diversity of male trees planted; and (3) the roles of social exchange networks in securing access to caprifigs using participant observation, open and semi-structured surveys, and an ego-centered protocol to study caprifig exchange networks. We document farmers’ knowledge regarding caprification, the pollinator life cycle, and the caprification of intermediate male fig generations under adverse climatic conditions. Caprifig exchange networks show the critical role of markets in obtaining caprifigs for early fig varieties and in exchanges among farmers for late varieties.
In nursery pollination mutualisms, which are usually obligate interactions, olfactory attraction of pollinators by floral volatile organic compounds (VOCs) is the main step in guaranteeing partner ...encounter. However, mechanisms ensuring the evolutionary stability of dioecious fig-pollinator mutualisms, in which female fig trees engage in pollination by deceit resulting in zero reproductive success of pollinators that visit them, are poorly understood. In dioecious figs, individuals of each sex should be selected to produce odours that their pollinating wasps cannot distinguish, especially since pollinators have usually only one choice of a nursery during their lifetime. To test the hypothesis of intersexual chemical mimicry, VOCs emitted by pollen-receptive figs of seven dioecious species were compared using headspace collection and gas chromatography-mass spectrometry analysis. First, fig-flower scents varied significantly among species, allowing host-species recognition. Second, in species in which male and female figs are synchronous, intersexual VOC variation was not significant. However, in species where figs of both sexes flower asynchronously, intersexual variation of VOCs was detectable. Finally, with one exception, there was no sexual dimorphism in scent quantity. We show that there are two ways to use scent to be a dioecious fig based on differences in flowering synchrony between the sexes.
Combining biogeographic, ecological, morphological, molecular and chemical data, we document departure from strict specialization in the fig-pollinating wasp mutualism. We show that the pollinating ...wasps Elisabethiella stuckenbergi and Elisabethiella socotrensis form a species complex of five lineages in East and Southern Africa. Up to two morphologically distinct lineages were found to co-occur locally in the southern African region. Wasps belonging to a single lineage were frequently the main regional pollinators of several Ficus species. In South Africa, two sister lineages, E. stuckenbergi and E. socotrensis, pollinate Ficus natalensis but only E. stuckenbergi also regularly pollinates Ficus burkei. The two wasp species co-occur in individual trees of F. natalensis throughout KwaZulu-Natal. Floral volatile blends emitted by F. natalensis in KwaZulu-Natal were similar to those emitted by F. burkei and different from those produced by other African Ficus species. The fig odour similarity suggests evolutionary convergence to attract particular wasp species. The observed pattern may result from selection for pollinator sharing among Ficus species. Such a process, with one wasp species regionally pollinating several hosts, but several wasp species pollinating a given Ficus species across its geographical range could play an important role in the evolutionary dynamics of the Ficus-pollinating wasp association.
Volatile organic compounds (VOCs) appear to be critical for mediating the extreme specificity of the obligatory mutualisms between
Ficus species (Moraceae) and their pollinating wasps (Hymenoptera, ...Chalcidoidea, Agaonidae). In the present study, we characterized the blend of VOCs emitted by receptive syconia of two closely related fig species
F. sur and
F. sycomorus. Headspace samples were collected, respectively, at three and four localities per species in South Africa and Swaziland, including one locality where both species were present, and were analyzed by gas chromatography–mass spectrometry (GC–MS) using a sensitive direct thermal desorption method. A total of 56 compounds were detected, most of which were terpenoids. Some of the major VOCs emitted by receptive figs are shared by both species. However, the relative proportions of these compounds in the total blend are different between
F. sur and
F. sycomorus. Multivariate analysis revealed a significant difference between the volatile profiles of the two species. These results support the hypothesis that the chemical messages emitted by figs are species-specific.
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