217 research outputs found
Dispersal of fig wasps (Hymenoptera: Chalcidoidea) across primary and logged rainforest in Sabah (Malaysia)
Sneaky African fig wasps that oviposit through holes drilled by other species
Watshamiella Wiebes species (Hymenoptera: Chalcidoidea: Pteromalidae: Sycoryctinae) were observed to engage, monitor and subsequently use oviposition holes made by other parasitoid fig wasp genera (Apocrypta Coquerel and Sycoryctes Mayr) to oviposit into host figs (Moraceae, Ficus) through the fig wall. They may be inquilines, klepto-parasitoids, or hyper-parasitoids; however, further biological investigations of larval diet are required to establish their life history strategy. Watshamiella species are morphologically robust, with enlarged fore femora and tibia, and aggressively interact with other fig wasps and ants. Our observations contribute towards unravelling the complex suite of behavioural adaptations and interactions involved in the community ecology of the obligate mutualism that exists between fig wasps and their host figs
A Diverse Mammal-Dominated, Footprint Assemblage from Wetland Deposits in the Lower Cretaceous of Maryland
A newly discovered assemblage of predominantly small tracks from the Cretaceous Patuxent Formation at NASAs Goddard Space Flight Center, Maryland, reveals one of the highest track densities and diversities ever reported (~70 tracks, representing at least eight morphotypes from an area of only ~2m(exp 2)). The assemblage is dominated by small mammal tracks including the new ichnotxon Sederipes goddardensis, indicating sitting postures. Small crow-sized theropod trackways, the first from this unit, indicate social trackmakers and suggest slow-paced foraging behavior. Tracks of pterosaurs, and other small vertebrates suggest activity on an organic-rich substrate. Large well-preserved sauropod and nodosaurs tracks indicate the presence of large dinosaurs. The Patuxent Formation together with the recently reported Angolan assemblage comprise the worlds two largest Mesozoic mammal footprint assemblages. The high density of footprint registration at the NASA site indicates special preservational and taphonomic conditions. These include early, penecontemporaneous deposition of siderite in organic rich, reducing wetland settings where even the flesh of body fossils can be mummified. Thus, the track-rich ironstone substrates of the Patuxent Formation, appear to preserve a unique vertebrate ichnofacies, with associated, exceptionally-preserved body fossil remains for which there are currently no other similar examples preserved in the fossil record
Few figs for frugivores : riparian fig trees in Zimbabwe may not be a dry season keystone resource
Most plants flower and fruit at times of year when probabilities of pollination and
seedling establishment are high. Fig trees (Ficus spp.) are often considered as keystone
resources for vertebrate frugivores, in part because of year-round fig production.
This unusual fruiting phenology results in the maintenance of fig wasp
populations, but in seasonal environments this means fruiting occurs during periods
when the chances of seedling establishment are low. Under these circumstances, selection
is expected to favour any individuals that reduce or eliminate fruiting at these
times. Here, we describe a large-scale survey of the extent of dry season fruiting by
three riparian Ficus species in Gonarezhou National Park, Zimbabwe. Few trees of
two monoecious species, F. sycomorus and F. abutilifolia, had figs, and most crops of
F. sycomorus were far smaller than the trees were capable of producing. Large stands
of the dioecious F. capreifolia were present, but fig densities were low and no mature
female (seed containing) figs were recorded. Even though fig trees may have been the
only species bearing fruit, the consequences of the low investment in reproduction
by the three Ficus species were clear—there were too few figs for a landscape-scale
keystone role.La plupart des plantes fleurissent et fructifient à des moments de l'année où les
probabilités de pollinisation et d'établissement des semis sont élevées. Les figuiers
(Ficus spp.) sont souvent considérés comme des ressources clés pour les frugivores
vertébrés, en partie grâce à la production de figues toute l'année. Cette phénologie
de fructification inhabituelle entraîne le maintien des populations de guêpes des figuiers,
mais dans les environnements saisonniers, cela signifie que la fructification se
produit pendant les périodes où les chances d'établissement des semis sont faibles.
Dans ces circonstances, la sélection devrait favoriser tous les individus qui réduisent
ou éliminent la fructification à ces moments. Nous décrivons ici une étude à grande
échelle portant sur l'étendue de la fructification en saison sèche par trois espèces riveraines de Ficus dans le parc national de Gonarezhou, au Zimbabwe. Peu d'arbres
de deux espèces monoïques, F. sycomorus et F. abutilifolia, avaient des figues et la
plupart des fruit du F. sycomorus étaient beaucoup plus petits que ceux que les arbres
étaient capables de produire. D’importants peuplements de F. capreifolia dioïque
étaient présents, mais les densités de figues étaient faibles et aucune figue femelle
mature (contenant des graines) n'a été enregistrée. Même si les figuiers étaient peutêtre
la seule espèce à produire des fruits, les conséquences du faible investissement
dans la reproduction par les trois espèces de Ficus étaient claires - il y avait trop peu
de figues pour qu’elles jouent un rôle clé à l'échelle du paysage.https://wileyonlinelibrary.com/journal/ajeam2020BiochemistryGeneticsMicrobiology and Plant Patholog
Non-pollinator fig wasp impact on the reproductive success of an invasive fig tree: why so little?
Classical biological control agents fail to achieve an impact on their hosts for a variety of reasons and an understanding of why they fail can help shape decisions on subsequent releases. Ornamental Ficus microcarpa is a widely planted avenue fig tree that is invasive in countries where its pollinator (Eupristina verticillata) is also introduced. This tree also supports more than 20 species of non-pollinating fig wasps (NPFW) that feed in the figs and have the potential to reduce the plant’s reproduction. Odontofroggatia galili, one of the most widely introduced NPFW, has larvae that develop in galled ovules that might otherwise develop into seeds or support pollinator larvae. We examined the distribution and relative abundance of the pollinator and O. galili on F. microcarpa in China, towards the northern limit of the tree’s natural range, and in Italy where the two species have been introduced. Where they co-existed, we also recorded the impact of varying densities of O. galili on F. microcarpa seed and pollinator production. O. galili and E. verticillata displayed contrasting habitat preferences in China, with O. galili almost absent from warmer sites. O. galili abundance and sex ratios varied between the natural and introduced ranges. Figs with more O. galili contained fewer seeds and pollinator offspring, but reproduction was rarely inhibited totally. Additional species with a greater impact in the figs they occupy are needed if biocontrol of F. microcarpa is to be effective
Are nanoparticles spherical or quasi-spherical?
The geometry of quasi-spherical nanoparticles is
investigated. The combination of SEM imaging and electrochemical
nano-impact experiments is demonstrated to allow sizing and characterization of the geometry of single silver
nanoparticles
Group cognitive analytic music therapy: a quasi-experimental feasibility study conducted in a high secure hospital
This study conducted a feasibility patient preference quasi-experimental study of group cognitive analytic music therapy (G-CAMT) for mentally disordered offenders. Participants either chose or were randomised to 16 sessions of manualised G-CAMT (N = 10) plus treatment as usual (TAU) or TAU alone (N = 10). Self-rated and staff-rated outcomes were assessed at baseline, post-intervention and 8-weeks post-intervention. Residency was assessed at 2-year follow-up. Results indicate that G-CAMT was easily implemented; 9/10 participants completed G-CAMT and attendees had high satisfaction with the approach. Session attendance was high; 4/10 participants attended all sessions. At the 8-week follow-up, 3/9 G-CAMT participants had reliable reductions (i.e. statistically reliable pre to 8-week follow-up change results) in intrusive/possessive behaviours and fear of separation/abandonment. On the staff-rated outcome measure G-CAMT participants as a group were statistically significantly friendlier compared to TAU at 8-week follow-up (U = 0.50, p = 0.009, d = 1.92, CI 0.44 to 3.11). There were no differences between the arms in terms of residency outcomes at 2-year follow-up. The study is discussed in terms of G-CAMT’s theoretical grounding and high acceptability. The study is limited by its small sample size, but indicates the possibility of progressing onto a full trial
Testing the thermal limits of Eccritotarsus catarinensis: a case of thermal plasticity
Water hyacinth is considered the most damaging aquatic weed in South Africa. The success of biocontrol initiatives against the weed varies nation-wide, but control remains generally unattainable in higher altitude, temperate regions. Eccritotarsus catarinensis (Hemiptera: Miridae) is a biocontrol agent of water hyacinth that was first released in South Africa in 1996. By 2011, it was established at over 30 sites across the country. These include the Kubusi River, a site with a temperate climate where agent establishment and persistence was unexpected. This study compared the critical thermal limits of the Kubusi River insect population with a laboratory-reared culture to determine whether any physiological plasticity was evident that could account for its unexpected establishment. There were no significant differences in critical thermal maxima (CTmax) or minima (CTmin) between sexes, while the effect of rate of temperature change on the thermal parameters in the experiments had a significant impact in some trials. Both CTmax and CTmin differed significantly between the two populations, with the field individuals tolerating significantly lower temperatures (CTmin: −0.3°C ± 0.063 [SE], CTmax: 42.8°C ± 0.155 [SE]) than those maintained in the laboratory (CTmin: 1.1°C ± 0.054 [SE], CTmax: 44.9°C ± 0.196 [SE]). Acclimation of each population to the environmental conditions typical of the other for a five-day period illustrated that short-term acclimation accounted for some, but not all of the variation between their lower thermal limits. This study provides evidence for the first cold-adapted strain of E. catarinensis in the field, with potential value for introduction into other colder regions where water hyacinth control is currently unattainable
Few figs for frugivores: Riparian fig trees in Zimbabwe may not be a dry season keystone resource
Most plants flower and fruit at times of year when probabilities of pollination and seedling establishment are high. Fig trees (Ficus spp.) are often considered as keystone resources for vertebrate frugivores, in part because of year‐round fig production. This unusual fruiting phenology results in the maintenance of fig wasp populations, but in seasonal environments this means fruiting occurs during periods when the chances of seedling establishment are low. Under these circumstances, selection is expected to favour any individuals that reduce or eliminate fruiting at these times. Here, we describe a large‐scale survey of the extent of dry season fruiting by three riparian Ficus species in Gonarezhou National Park, Zimbabwe. Few trees of two monoecious species, F. sycomorus and F. abutilifolia, had figs, and most crops of F. sycomorus were far smaller than the trees were capable of producing. Large stands of the dioecious F. capreifolia were present, but fig densities were low and no mature female (seed containing) figs were recorded. Even though fig trees may have been the only species bearing fruit, the consequences of the low investment in reproduction by the three Ficus species were clear—there were too few figs for a landscape‐scale keystone role
Rift Valley Fever Risk Map Model and Seroprevalence in Selected Wild Ungulates and Camels from Kenya
Since the first isolation of Rift Valley fever virus (RVFV) in the 1930s, there have been multiple epizootics and epidemics in animals and humans in sub-Saharan Africa. Prospective climate-based models have recently been developed that flag areas at risk of RVFV transmission in endemic regions based on key environmental indicators that precede Rift Valley fever (RVF) epizootics and epidemics. Although the timing and locations of human case data from the 2006-2007 RVF outbreak in Kenya have been compared to risk zones flagged by the model, seroprevalence of RVF antibodies in wildlife has not yet been analyzed in light of temporal and spatial predictions of RVF activity. Primarily wild ungulate serum samples from periods before, during, and after the 2006-2007 RVF epizootic were analyzed for the presence of RVFV IgM and/or IgG antibody. Results show an increase in RVF seropositivity from samples collected in 2007 (31.8%), compared to antibody prevalence observed from 2000-2006 (3.3%). After the epizootic, average RVF seropositivity diminished to 5% in samples collected from 2008-2009. Overlaying maps of modeled RVF risk assessments with sampling locations indicated positive RVF serology in several species of wild ungulate in or near areas flagged as being at risk for RVF. Our results establish the need to continue and expand sero-surveillance of wildlife species Kenya and elsewhere in the Horn of Africa to further calibrate and improve the RVF risk model, and better understand the dynamics of RVFV transmission
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