Biodiversity evaluation: From endorsed indexes to inclusion of a pollinator indicator

There is increasing interest in evaluating biodiversity to preserve ecosystem services. Researchers can sustain policymakers by providing tools, such as indexes and indicators, that need constant implementation to become accepted standards. Implementation may vary from re-evaluation of existing indicators to introduction of new ones based on emerging threats to biodiversity. With the aim of contributing to the compelling need to estimate and counterbalance pollinator loss, we screened existing bioindicators. We first selected indexes/indicators applied to agricultural contexts and concurrently endorsed by a regulatory agency. We then extended our analysis to indexes/indicators based on arthropod taxa and formally recognized at least by national bodies. Our procedure identified a combination of surveys of various animal taxa and remote landscape analyses (e.g., using a GIS and other cartographic tools). When the animals are arthropods, most indexes/indicators can only address confined environments (e.g., grasslands, riversides). Indicator strength was improved by the simultaneous inclusion of biotic and abiotic components. Pollinator sensitivity to changes at micro-habitat level is widely appreciated and may help distinguish agricultural practices. A biodiversity index based on pollinators, including a wide monitoring scheme supplemented by citizen science, is currently fostered at the European level. The results obtained using such an index may finally enable focusing of strategic funding. Our analysis will help to reach this goal

Simple and informative: applying a basic Anthophila monitoring scheme in a simplified insular ecosystem

The decline of pollinators and the consequent decay of pollination services call for the establishment of monitoring schemes for several groups of pollinators. For Anthophila (Hymenoptera), the design of monitoring schemes is still under development. The main difficulties lie in combining a reliable but field-feasible taxonomic identification with the collection of informative data about the consistency and functional role of pollinator populations. Here we report on the application of the Italian monitoring scheme for pollinators recently defined by ISPRA and the University of Turin in agreement with the European Pollinators Monitoring Scheme on the small island of Giannutri (Tuscany), a simplified insular ecosystem with a virtually unknown pollinator community. This island has recently experienced a drastic change in its bee community, as since 2018 honey bee (Apis mellifera L.) hives are regularly moved every year to the island for breeding purposes. In the spring 2021 we established six 250 m long fixed transects and performed a total of 48 surveys (8 for each transect), recording more than 2300 observations of 9 Anthophila bee taxa and the flowers they visited. By using generalised additive mixed models, we showed that the monitoring protocol has a good potential for monitoring Anthophila, as we could verify several expected relationships between Anthophila abundance and abiotic factors (season, hour of the day, distance from the apiary) and biotic factors (abundance of flower resources). More importantly, we verified that A. mellifera represents by far the most frequent Anthophila taxon. Our data do not show evidence for spatial partition between A. mellifera and the other most frequent taxa (Bombus terrestris L. and Anthophora spp.). The visit network based on transect observations also showed that these taxa largely overlapped in terms of visits to flower resources. Overall, our data showed that the monitoring protocol allows gathering informative data about Anthophila taxa abundance, interactions and flower-visits. Moreover, the spatial and flower-visit overlap suggest potential for competition between honey bees and wild pollinators, with a potential consequent resource depletion for the latter. While this hypothesis could only be assessed by a long-term monitoring and ad hoc honey bee removal experiments, our data show that this basic monitoring protocol produces rapid and valuable information about Anthophila community and dynamics

Updated distribution of the invasive Megachile sculpturalis (Hymenoptera: Megachilidae) in Italy and its first record on a Mediterranean island

Megachile sculpturalis (Smith, 1853) (Hymenoptera: Megachilidae) is an invasive solitary bee that is rapidly spreading all over Europe. The present study aims to update the distribution of this species in Italy. The research led to the collection of 177 records, obtained through bibliographic research and data-mining from websites, blogs and social networks. We here present the first record of M. sculpturalis on a Mediterranean island and discuss its possible effect on the native ecosystem. Given the particular discovery of M. sculpturalis on Elba Island (Tuscany), we suggest possible monitoring, containment and possible eradication measures of the species

Pollen load analysis reveals feeding preference of bee pollinators of Dictamnus albus

Dictamnus albus L., commonly known as dittany, is a long-lived perennial herb belonging to the family Rutaceae; its flowers produce abundant pollen and nectar and are visited by several pollinating insects. Observations on insect behaviour while foraging on D. albus flowers showed that medium to large bees have the highest percentage of contacts with receptive stigmas, i.e. they show the highest probability of acting as valuable pollinators. However, this can be proved through the analysis of the pollen present on their body. We separately collected the pollen sparse on insect body (head, thorax and abdomen) and the pollen actively collected in specialized structures (corbiculae, scopae), in order to assess the fidelity of each visitor taxon, determined as the mean percentage of specific (D. albus) pollen. In addition, we performed a more precise analysis of the pollen load of the main pollinators of D. albus: Habropoda tarsata, Bombus spp. and Megachilidae spp.. For these insect taxa we identified pollen grains at the genus or family level, to infer the levels of competition or synergy among co-flowering species, and to obtain additional information on insect feeding habits. Most visitors showed a high fidelity to D. albus in the study area, meaning that it is a good resource of rewards, and the potentially best pollinators of dittany tend to prefer its flowers compared to co-flowering species, indicating a low competition during full blooming. From the insect perspective, different plants may be source of different rewards at a same time. For example, dittany is mainly visited for nectar by most pollinators but other flowering species are visited for pollen or nectar as well. This study allows us to explore the interactions among species in a complex ecological context and to develop specific conservation actions at both the plant and insect levels

Using occurrence data to evaluate extinction reveals a strong resilience of butterflies in a National Park of Southern Europe (Alta Murgia National Park)

Butterflies from southernmost European regions encompass a large fraction of faunistic and genetic diversity but are also at the forefront of extinction risk for climate change. Nevertheless, monitoring schemes aimed at detecting their population trends were only recently established. In this study, we gathered all occurrence records of the 81 species of butterflies recorded for the Alta Murgia National Park (Italy, Apulia), a prime conservation area for butterflies. By using literature, citizen science, and unpublished sample data, we traced potential extinctions since 1966. We also provided a dedicated index to evaluate the potential extinction at the whole community level. We found that among the 29 species recorded before 2009, three were not recovered from 2009 to 2021. Another group of nine species was not recorded in the last five years. However, given the not standardized sampling methodology and the possibility that apparently disappeared species were due to inaccurate identification, we conclude that the butterfly community of the Park is showing a strong resilience. We hypothesize that such resilience may be attributed to the existence of the protected area and the presence of heterogeneous environments, which allow to buffer climatic changes and any other negative anthropic effects. The objective recognition of rare species in the surrounding region of 200 km ray also allowed identifying which species should be considered as prime targets for the conservation of local and regional diversity

Features of 'CD4-exploders', HIV-positive patients with an optimal immune reconstitution after potent antiretroviral therapy

Objective: To identify crucial immunological characteristics of a group of patients, defined \ub4CD4-exploders\ub4, who were able to fully reconstitute their immune system after receiving highly active antiretroviral therapy (HAART). Patients: Among a population of 540 HIV-positive patients treated with HAART, six individuals were identified who experienced a nadir of less than 85 X 10(6) CD4+ cells/l, had major opportunistic infections (four out of six), started HAART in 1996 or 1997, and showed a rapid and relevant CD4+ lymphocyte increase (mainly due to virgin cells), in some cases regardless of virological control. Methods: Enzyme-linked immunosorbent assay for the determination of interleukin (IL)-7 plasma levels; flow cytometry to analyse surface antigens and CD127 (IL-7 receptor alpha-chain) expression; quantitative-competitive (QC) PCR for detecting cells containing T-cell receptor rearrangement excision circles (TREC) chest-computed tomography (CT) to analyse thymus volume and content. Results: In \ub4CD4-exploders\ub4, high levels of TREC+ lymphocytes were found among CD4+ T cells, which also contained a high percentage of naive cells. However, CT revealed a dramatic depletion of intrathymic lymphoid tissue. Plasma levels of IL-7 were significantly high. Most CD4+ and CD8+ T lymphocytes expressed CD127, whose level was similar to that of healthy donors. CD127 expression on CD8+ lymphocytes was markedly higher than in HIV-positive individuals treated with the same therapy or in patients with AIDS. Conclusion: In \ub4CD4-exploders\ub4, HAART-incluced reconstitution of the T-cell compartment is independent from thymus volume, and is favoured by the upregulation of the IL-7/IL-7 receptor system

Genetic polymorphisms of Fas (CD95) and FasL (CD178) in human longevity: studies on centenarians

Apoptosis plays a crucial role in immunosenescence, as also evidenced by the increased expression of Fas in lymphocytes from aged people. However, little is known about the genetic regulation of Fas and its ligand, FasL. We have studied their polymorphisms in 50 centenarians and 86 young donors living in Northern Italy. The first Fas polymorphism; at position -670, has in Caucasian a heterozigosity of 51%; the second, at -1377 position, has the wild type allele (G) with a very high frequency (83%) respect to the mutant allele. Genotype and allele distribution for both polymorphisms were similar in controls and centenarians. Similar results were found as far as two FasL polymorphisms (IVS2nt-124 and IVS3nt169) are concerned. On the whole, our data suggest that Fas and FasL polymorphisms, as well as their haplotypes, are unlikely to be associated with successful human longevity