Analisi di impurita solide nei mieli della Lucchesia mediante Filth test: evoluzione della qualita negli ultimi 15 anni

Il miele, prodotto naturale per eccellenza, è conosciuto fin dall’antichità per le sue caratteristiche nutrizionali e salutistiche. Secondo la normativa vigente, il miele immesso sul mercato deve essere privo di sostanze organiche ed inorganiche estranee alla sua composizione. Nonostante ciò, sottoponendo il miele a Filth test è possibile ritrovare delle impurità appartenenti a diverse classi: impurità di origine animale, di origine carboniosa, impurità varie. In questa tesi, sono stati sottoposti a Filth test 24 campioni di miele, 19 provenienti da produttori toscani della Lucchesia e 5 dalla grande distribuzione; le impurità ritrovate sono state determinate, suddivise in classi quantitative e i risultati ottenuti sono stati messi a confronto con quelli derivanti da una precedente indagine condotta presso il DiSAAA-a dell'Università di Pisa nel periodo 1996-1999, sempre relativa a Filth test su 55 campioni di miele provenienti dalla Lucchesia. Dal confronto è emerso un complessivo miglioramento della qualità del miele in termini di impurità solide individuabili dovuto a diversi fattori, di cui i principali sono rappresentati da importanti cambiamenti nel quadro normativo in riferimento all'igiene dei prodotti primari, oltre che da miglioramenti del grado di conoscenza da parte del produttore in virtù dell'aumentato livello di formazione specifica. A questo contribuisce anche il ricambio generazionale in atto presso le aziende apistiche nazionali

Prevalence of the microsporidian Nosema ceranae in honeybee (Apis mellifera) apiaries in Central Italy

Nosema ceranae and Nosema apis are microsporidia which play an important role in the epidemiology of honeybee microsporidiosis worldwide. Nosemiasis reduces honeybee population size and causes significant losses in honey production. To the best of our knowledge, limited information is available about the prevalence of nosemiasis in Italy. In this research, we determined the occurrence of Nosema infection in Central Italy. Thirty-eight seemingly healthy apiaries (2 to 4 hives each) were randomly selected and screened from April to September 2014 (n= 11) or from May to September 2015 (n= 27). The apiaries were located in six areas of Central Italy, including Lucca (n= 11), Massa Carrara (n= 9), Pisa (n= 9), Leghorn (n= 7), Florence (n= 1), and Prato (n= 1) provinces. Light microscopy was carried out according to current OIE recommendations to screen the presence of microsporidiosis in adult worker honeybees. Since the morphological characteristics of N. ceranae and N. apis spores are similar and can hardly be distinguished by optical microscopy, all samples were also screened by multiplex polymerase chain reaction (M-PCR) assay based on 16S rRNA-gene-targeted species-specific primers to differentiate N. ceranae from N. apis. Furthermore, PCR-positive samples were also sequenced to confirm the species of amplified Nosema DNA. Notably, Nosema spores were detected in samples from 24 out of 38 (63.2%, 95% CI: 47.8–78.5%) apiaries. Positivity rates in single provinces were 10/11, 8/9, 3/9, 1/7, or 1/1 (n= 2). A full agreement (Cohen’s Kappa = 1) was assessed between microscopy and M-PCR. Based on M-PCR and DNA sequencing results, only N. ceranae was found. Overall, our results highlighted that N. ceranae infection occurs frequently in the cohort of honeybee populations that was examined despite the lack of clinical signs. These findings suggest that colony disease outbreaks might result from environmental factors that lead to higher susceptibility of honeybees to this microsporidian

Larvicidal and ovideterrent properties of neem oil and fractions against the filariasis vector Aedes albopictus (Diptera: Culicidae): a bioactivity survey across production sites

Neem seed oil (NSO) of Azadirachta indica (Meliaceae) contains more than 100 determined biologically active compounds, and many formulations deriving from them showed toxicity, antifeedancy and repellence against a number of arthropod pests. However, it is widely known that botanical products can differ in their chemical composition and bioactivity, as function of the production site and production process. We used high-performance thin layer chromatography (HPTLC) to investigate differences in chemical constituents of NSOs from three production sites. HPTLC analyses showed several differences in chemical abundance and diversity among NSOs, with special reference to limonoids. Furthermore, the three NSOs and their fractions of increasing polarities [i.e. ethyl acetate (EA) fraction and butanol (BU) fraction] were evaluated for larvicidal toxicity and field oviposition deterrence against the Asian tiger mosquito, Aedes albopictus, currently the most invasive mosquito worldwide. Results from bioactivity experiments showed good toxicity of NSOs and EA fractions against A. albopictus fourth instarlarvae (with LC50 values ranging from 142.28 to 209.73 ppm), while little toxicity was exerted by BU fractions. A significant effect of the production site and dosage was also found and is probably linked to differences in abundance of constituents among samples, as highlighted by HPTLC analyses. NSOs and EAs were also able to deter A. albopictus oviposition in the field (effective repellence values ranging from 98.55 to 70.10 %), while little effectiveness of BU fractions was found. Concerning ovideterrent activity, no difference due to the production site was found. This is the first report concerning larvicidal toxicity of NSO against A. albopictus and ovideterrence against Culicidae in the field. The chance to use chemicals fromthe NSO EA fraction seems promising, since they are effective at lower doses, if compared to synthetic products currently marketed, and could be an advantageous alternative to build newer and safer mosquito control tools

Cannabis sativa and Humulus lupulus essential oils as novel control tools against the invasive mosquito Aedes albopictus and fresh water snail Physella acuta

Over the past several decades, there has been a resurgence of interest in industrial hemp (Cannabis sativa L., Cannabaceae) cultivation. Besides fibre, seeds and oil, hemp contains high quantity of essential oil (EO). Hop (Humulus lupulus L., Cannabaceae) is a high-climbing, perennial vine, largely utilized in the brewing industry to add flavour and bitterness to beer. While it is known that hop also contains α- and ß-acids, and terpenes that have been found to be toxic, anti-feedant, and repellent for insects and mites, little is known about the bioactivity against problematic species of the hemp EO. In this study, the chemical composition of the EOs from C. sativa and H. lupulus was evaluated by GC-MS, and their acute toxicity was assessed against the Asian tiger mosquito Aedes albopictus (Skuse) (Diptera Culicidae) and, the freshwater bladder snail Physella acuta (Draparnaud) (Mollusca Physidae), two problematic invasive species. Furthermore, we evaluated the toxicity of both EOs against a non-target insect, the mayfly Cloeon dipterum L. (Ephemeroptera Baetidae). Both EOs were toxic against the three tested species. The most effective EO was the C. sativa, able to kill 100% of P. acuta snails starting from 100 μL L-1. C. sativa LC50 were 301.560, 282.174 and, 35.370 μL L-1, while H. lupulus LC50 were 330.855, 219.787 and, 118.653 μL L-1 against A. albopictus, C. dipterum and P. acuta, respectively. Relative median potency analysis showed that the C. sativa EO was more toxic than H. lupulus against A. albopictus and P. acuta, while H. lupulus was more toxic than C. sativa EO against C. dipterum. The most susceptible species to the two EOs was P. acuta, while A. albopictus resulted the least susceptible one

Who is polluting Italian honey? A filth test survey

Honey is largely considered a natural and healthy product. Investigation on foreign matter in honey provides useful information to evaluate honey quality standards in apiary, honey extraction and packaging phases. Indeed, toxic substances (antibiotics, pesticides and heavy metals) as well as foreign matter (e.g. arthropods, hairs) can contaminate honey, acting as allergens or vectors of human pathogens. We used the filth test to evaluate the presence of foreign matter in samples of Italian honeys, mainly from Tuscany. We revealed a high number of carbon particles and other inorganic fragments, followed by fragments of animal origin. This latter included whole small insects, their cuticular fragments, mites and mammal hairs. The kind of contamination allowed us to evidence uncorrected apicultural practices and to suggest the appropriate corrective measures. The filth test method is an excellent and cheap tool to check honey quality, requiring minimal instrumental equipment and giving results that can be interpreted quickly

Artemisia spp. essential oils against the disease-carrying blowfly Calliphora vomitoria

Background: Synanthropic flies play a considerable role in the transmission of pathogenic and non-pathogenic microorganisms. In this work, the essential oil (EO) of two aromatic plants, Artemisia annua and A. dracunculus, were evaluated for their abilities to control the blowfly Calliphora vomitoria. A. annua and A. dracunculus EOs were extracted, analysed and tested in laboratory bioassays. Besides, the physiology of EOs toxicity and the EOs antibacterial and antifungal properties were evaluated. Results: Both Artemisia EOs were able to deter C. vomitoria oviposition on fresh beef meat. At 0.05 μL cm-2 A. dracunculus EO completely inhibited C. vomitoria oviposition. Toxicity tests, by contact, showed LD50 of 0.49 and 0.79 μL EO per fly for A. dracunculus and A. annua, respectively. By fumigation, LC50 values were 49.54 and 88.09 μL L-1 air for A. dracunculus and A. annua, respectively. EOs AChE inhibition in C. vomitoria (IC50 = 202.6 and 472.4 mg L-1, respectively for A. dracunculus and A. annua) indicated that insect neural sites are targeted by the EOs toxicity. Finally, the antibacterial and antifungal activities of the two Artemisia EOs may assist in the reduction of transmission of microbial infections/contaminations. Conclusions: Results suggest that Artemisia EOs could be of use in the control of C. vomitoria, a common vector of pathogenic microorganisms and agent of human and animal cutaneous myiasis. The prevention of pathogenic and parasitic infections is a priority for human and animal health. The Artemisia EOs could represent an eco-friendly, low-cost alternative to synthetic repellents and insecticides to fight synanthropic disease-carrying blowflies

Mediterranean essential oils as effective weapons against the West Nile vector Culex pipiens and the Echinostoma intermediate host Physella acuta: what happens around? An acute toxicity survey on non-target mayflies

Mosquitoes (Diptera: Culicidae) represent a threat for millions of people worldwide, since they act as vectors for important pathogens, including malaria, yellow fever, dengue and West Nile. Second to malaria as the world's most widespread parasitic disease, infection by trematodes is a devastating public health problem. In this study, we proposed two essential oils from plants cultivated in Mediterranean regions as effective chemicals against mosquitoes and freshwater snails vectors of Echinostoma trematodes. Chemical composition of essential oils from Achillea millefolium (Asteraceae) and Haplophyllum tuberculatum (Rutaceae) was investigated. Acute toxicity was evaluated against larvae of the West Nile vector Culex pipiens (Diptera: Culicidae) and the invasive freshwater snail Physella acuta (Mollusca: Physidae), an important intermediate host of many parasites, including Echinostoma revolutum (Echinostomidae). Acute toxicity of essential oils was assessed also on a non-target aquatic organism, the mayfly Cloeon dipterum (Ephemeroptera: Baetidae). Achillea millefolium and H. tuberculatum essentials oils were mainly composed by oxygenated monoterpenes (59.3 and 71.0 % of the whole oil, respectively). Chrysanthenone and borneol were the two major constituents of Achillea millefolium essential oil (24.1 and 14.2 %, respectively). Major compounds of H. tuberculatum essential oil were cis-p-menth-2-en-1-ol and trans-p-menth-2-en-1-ol (22.9 and 16.1 %, respectively). In acute toxicity assays, C. pipiens LC50 was 154.190 and 175.268 ppm for Achillea millefolium and H. tuberculatum, respectively. P. acuta LC50 was 112.911 and 73.695 ppm for Achillea millefolium and H. tuberculatum, respectively, while the same values were 198.116 and 280.265 ppm for C. dipterum. Relative median potency analysis showed that both tested essential oils were more toxic to P. acuta over C. dipterum. This research adds knowledge on plant-borne chemicals toxic against invertebrates of medical importance, allowing us to propose the tested oils as effective candidates to develop newer and safer vector control tools

The beer brewing waste spent hops (Humulus lupulus H.) as a valuable source of repellents useful to ward off insect attacks to stored food

Hop, Humulus lupulus L., is an aromatic plant largely utilized in the brewing industry to add flavour and bitterness to beer. As a consequence, a large amount of residual material, named “spent hops”, is produced by the brewing industry. Since only about 15% of the hop constituents end up in the beer, spent hops should be further valorised as a low-cost source of bioactive substances. In this study, hops and spent hops were evaluated as a source of essential oil (EO) with repellent activity against two of the main stored food insect pests. Hops and spent hops EO yields were about 2.4% and 0.1%, respectively. The main components of both the EOs were the terpenes myrcene, α-humulene, and β-caryophyllene. The main chemical difference between hops and spent hops was the myrcene percentage. Area preference method bioassays showed that spent hops EO exerted a strong repellency against the lesser grain borer, Rhyzopertha dominica (F.) (Bostrichidae) and the granary weevil, Sitophilus granarius (L.) (Curculionidae). RD50 values indicated that R. dominica was about 20 time more susceptible to spent hops EO than S. granarius. Among the EO components, myrcene was the strongest repellent against R. dominica while limonene was the most effective compound against S. granarius. However, overall, for its much higher content, myrcene can be considered the compound that mostly contributes to the repellent activity of spent hops EO. These results show that spent hops could be an excellent, virtually costless, source of EO to be utilized as eco-friendly repellent in the protection of stored food from insect pests