Uncovering the spatial pattern of invasion of the honeybee pest small hive beetle, Aethina tumida, in Italy

ABSTRACT The fast tracking of invasion spatial patterns of alien species is crucial for the implementation of preventive and management strategies of those species. Recently, a honeybee pest, the small hive beetle Aethina tumida (hereafter SHB), has been reported in Italy, where it colonized more than 50 apiaries in an area of about 300 km2. SHB is a nest parasite and scavenger of honeybee colonies native of Sub-Saharian Africa. Likely being helped by the globalization of apiculture, SHB underwent several invasions in the last twenty years, causing locally relevant economic impact. While many features of its biology have been addressed, an important knowledge gap concerns the spatial invasion dynamics in invaded areas. In this paper we coupled two spatial analysis techniques (geographic profiling and a density-based spatial clustering algorithm) to uncover the possible invasion pattern of SHB in Italy. We identified the port town of Gioia Tauro as the most likely point from which SHB may have spread and suggested the possible successive axes of diffusion. These putative diffusion paths suggest that the SHB spread in south Italy might have been due to a mix of natural dispersal between close apiaries and longer distance movement through faster, likely human-mediated, communication routes.

Snow's case revisited: new tool in geographic profiling of epidemiology

Abstract Geographic Profiling technique is used to find the origin of a series of crimes. The method was recently extended to other fields. One of the best renowned data in epidemiology is that by John Snow during an outburst of cholera in London. We wrote Python scripts to perform the analyses to apply the Geographic Profiling for individuating the starting origin of an infection by using the old Snow's data set. We modified the method by applying a weight to each point of the map where cases of cholera were reported. The weight was proportional to the number of cases in a given location.This modification of the Geographic Profiling method allowed to individuate in the map an area of maximum probability of the infection source, which was a few meters wide and including the historically known source of cholera, that is the "classical" water pump at Broad Street.The method appears to be a useful complement in order to individuate the source of epidemics when available data about the cases of the infections can be summarized on a map.

A new quantitative classification of ecological types in the bromeliad genus Tillandsia (Bromeliaceae) based on trichomes

Using collection specimens, we measured the density and wing area of trichomes in 37 species of the bromeliad genus Tillandsia, specifically the abaxial proximal, abaxial distal, adaxial proximal and adaxial distal parts of the leaf. The product of the trichome "wing" area by the number of trichomes (means) produced a pure number (T) that was correlated to ecological features. The correlation was positive with respect to arid environments (xeric Tillands) and negative with respect to humid environments (mesic Tillands). Bulbous, and particularly myrmecophytic species and species with tanks, represented particular categories. Other intermediate types were identified based on the T number, totalling five ecological types. In comparison with other systems of ecological typification for Tillands and other Bromeliaceae, the present system offers measurable data whose analysis is reproducible.

Medimos el número por milímetro cuadrado y el área del “ala” (parte móvil) de los tricomas en las partes adaxial próxima y distal, y adaxial próxima y distal, de la hoja de 37 especies de bromelias del género Tillandsia. El producto del área del ala para el número de los tricomas (promedio) produjo un número puro (T). Hallamos que T se correlaciona con las características ecológicas de las tilandsias investigadas. La correlación es positiva con respecto a ambientes áridos (especies xéricas) y negativa con respecto a los ambientes húmedos (especies mésicas). Las especies con bulbo, y particularmente las asociadas con hormigas y especies con de tanque representan categorías particulares. Identificamos otros tipos intermedios, agradando así cinco tipos ecológicos. En comparación con otros sistemas de tipificación ecológica, este sistema ofrece la ventaja de ser reproducible y cuantitativo.

Molecular evidence of polyphyletism in the plant genus Carum L. (Apiaceae)

An analysis of internal transcribed spacer (ITS) DNA sequences of the four species of Carum L. (Apiaceae) known in Italy revealed that this genus is polyphyletic. Maximum parsimony with bootstrap resampling, maximum likelihood and Bayesian inference analyses resulted in three distinct clades: Carum carvi L. clustered within tribe Careae Baill. (former Aegopodium clade); Hellenocarum multiflorum (= Carum multiflorum), Carum heldreichii and Carum appuanum clustered within the tribe Pyramidoptereae Boiss.; and H. multiflorum and C. heldreichii formed a well supported clade. Since the sister group of H. multiflorum and C. heldreichii was Bunium elegans the autonomy of Hellenocarum from Carum is confirmed by our study. We also found that C. appuanum clustered separately from the other Carum species, with the closest related species appearing to be Scaligeria moreana but this still had few morphological similarities with C. appuanum.

The use of tropical bromeliads (Tillandsia spp. ) for monitoring atmospheric pollution in the town of Florence, Italy

The results of an experiment with two species of epiphytic angiosperms (Tillandsia caput-medusae and T. bulbosa) for monitoring polycyclic aromatic hydrocarbons (PAHs) in the air of Florence, Italy, are presented. PAHs are compounds known to be dangerous because of their carcinogenic potential, and among cormophytes, tillands (monocotyledons equipped with peculiar, specialised, epidermal trichomes) are considered promising for air pollution biomonitoring. PAHs data were obtained using GC/MS analysis of plant extracts. Analytical data indicated an increasing trend in time of PAHs bioaccumulation. This result was compared with instrumentally recorded parameters such as meteorological (rain) and environmental ones (PM10), indicating that trichome-operated physical capture of aerial particles was prominent in PAHs bioaccumulation on tillands. SEM (scanning electron microscope) observations confirmed the role of the trichomes. This work indicates that tillands are particularly useful, low-cost biomonitoring organisms inside their area of distribution (all Latin American countries and southern USA) where these plants are easily available, but also wherever the climate allows them to survive.