Pathogenic potential of Beauveria pseudobassiana as bioinsecticide in protein baits for the control of the medfly Ceratitis capitata

The medfly, Ceratitis capitata (Wiedemann) (Diptera Tephritidae), is a major insect pest affecting fruit production worldwide whose control is mainly based on the use of protein baits laced with chemical insecticides. Entomopathogenic fungi are well- known to be effective against a wide spectrum of insect pests and are commonly utilized in integrated pest management and bio- logical control programs. Here, we assess the feasibility of using the recently described entomopathogenic species Beauveria pseudobassiana Rehner et Humber (Hypocreales Cordycipitaceae) as a biological insecticide in protein bait sprays for the control of the medfly. Firstly, we evaluated the pathogenicity of B. pseudobassiana against eggs, larvae, pupae and adults of the medfly. Secondly, we tested its efficacy as bioinsecticide in protein bait sprays. The results of the pathogenicity tests showed that B. pseu- dobassiana is able to infect, and lead to the death, all instar of the medfly. The efficacy of B. pseudobassiana was confirmed also when used as bioinsecticide in protein baits. In planta tests, the survival probability (Kaplan-Meier estimates) of flies in contact with the B. pseudobassiana-laced protein bait was significantly lower respect to control. Median survival time of flies treated with B. pseudobassiana-laced protein (6 ± 1.422 d) was at least three times shorter than in control (> 20 d). Based on our results, we confirmed the potential of B. pseudobassiana as bioinsecticide in entomopathogenic fungi-laced protein baits for the control of tephritid fruit flies

Insecticidal potential of Brevibacillus laterosporus against dipteran pest species in a wide ecological range

In order to increase our understanding of the insecticidal potential of the entomopathogenic bacterium Brevibacillus laterosporus strain UNISS 18 against insect pests, investigations were conducted on a selection of dipteran species including fruit flies, house flies, blow flies, and mosquitoes, characterized by adaptations to very diverse habitats. According to lethal concentration (LC50) values, the common house mosquito Culex pipiens (LC50 = 0.10 × 106 spores/mL) and the yellow fever mosquito Aedes aegypti (LC50 = 0.18 × 106 spores/mL) were significantly more susceptible than the flies. The blow flies were the second taxon in term of susceptibility to B. laterosporus spores, with a higher mortality in Calliphora vomitoria (LC50 = 78.84 × 106 spores/mL) than Lucilia caesar (LC50 = 148.30 × 106 spores/mL). The effectiveness of B. laterosporus spores was reduced by half in the house fly Musca domestica (LC50 = 82.41 × 106 spores/mL). The lowest susceptibility was observed in the fruit flies, among which the spotted wing drosophila (SWD), Drosophila suzukii, was the most susceptible (LC50 = 217.51 × 106 spores/ mL) in comparison with the medfly Ceratitis capitata and the olive fly Bactrocera oleae (LC50 = 2567.32 and 2567.36 × 106 spores/mL, respectively). The present study demonstrated that significantly different degrees of susceptibility are associated with diverse dipteran species including plant and animal parasites, and we suggest that B. laterosporus established different relationships with dipteran species in different ecosystem

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

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

Assessment of the Life Cycle Environmental Impact of the Olive Oil Extraction Solid Wastes in the European Union

There is an increasing interest in developing sustainable systems in the European Union (EU) to recover and upgrade the solid wastes of the olive oil extraction process, i.e. wet husk. A Life Cycle Environmental Impact Assessment (LCIA) of wet husk has been carried out aiming at facilitating an appropriate Life Cycle Management of this biomass. Three scenarios have been considered, i.e. combustion for domestic heat, generation of electric power, and composting. The Environmental Product Declaration and the ReCiPe method were used for Life Cycle Impact Assessment. Domestic heating and power generation were the most important impact factors in damaging human health, ecosystems, and natural resources depletion. Composting was 2-4 orders of magnitude less impacting than domestic heat and power generation. Considering human health, the impact of climate change, human toxicity and particulate matter formation represented the main impact categories. Considering ecosystems, climate change and natural land transformation were the main impact categories. Within natural resources, fossil fuel depletion was impacted three orders more than metal depletion. Within domestic heating and power generation scenarios, storage of wet husk along with the extraction by organic solvent, and the waste treatment were the most impacting phases for global warming potential, ozone layer depletion, acidification and non renewable fossil resources depletion. The results obtained for the waste disposal have been comparatively assessed with respect to the environmental impact of the olive oil production chain

Changes in soil aggregation and glomalin-related soil protein content as affected by the arbuscular mycorrhizal fungal species Glomus mosseae and Glomus intraradices.

Arbuscular mycorrhizal (AM) fungi are key organisms of the soil/plant system, influencing soil fertility and plant nutrition, and contributing to soil aggregation and soil structure stability by the combined action of extraradical hyphae and of an insoluble, hydrophobic proteinaceous substance named glomalin-related soil protein (GRSP). Since the GRSP extraction procedures have recently revealed problems related to co-extracting substances, the relationship between GRSP and AM fungi still remains to be verified. In this work the hypothesis that GRSP concentration is positively correlated with the occurrence of AM fungi was tested by using Medicago sativa plants inoculated with different isolates of Glomus mosseae and Glomus intraradices in a microcosm experiment. Our results show that (i) mycorrhizal establishment produced an increase in GRSP concentration – compared to initial values – in contrast with non-mycorrhizal plants, which did not produce any change; (ii) aggregate stability, evaluated as mean weight diameter (MWD) of macroaggregates of 1–2 mm diameter, was significantly higher in mycorrhizal soils compared to non-mycorrhizal soil; (iii) GRSP concentration and soil aggregate stability were positively correlated with mycorrhizal root volume and weakly correlated with total root volume; (iv) MWD values of soil aggregates were positively correlated with values of total hyphal length and hyphal density of the AM fungi utilized. The different ability of AM fungal isolates to affect GRSP concentration and to form extensive and dense mycelial networks, which may directly affect soil aggregates stability by hyphal enmeshment of soil particles, suggests the possibility of selecting the most efficient isolates to be utilized for soil quality improvement and land restoration programs

Impact of nitrogen fertilization and soil tillage on arbuscular mycorrhizal fungal communities in a Mediterranean agroecosystem

The impact of nitrogen (N) fertilization and tillage on arbuscular mycorrhizal fungi (AMF) was studied in a Mediterranean arable system by combining molecular, biochemical and morphological analyses of field soil and of soil and roots from trap plants grown in microcosm. Canonical correspondence analysis (CCA) of PCR–DGGE banding patterns evidenced that AMF communities in the field are affected by N-fertilization and tillage. N-fertilization was also the main factor shaping AMF communities in Medicago sativa trap plant soil and roots. The overall sporulation pattern of the different AMF species showed a predominant effect of tillage on AMF communities, as shown by CCA analysis. Funneliformis mosseae was the predominant species sporulating in tilled soils, while Glomus viscosum and Glomus intraradices prevailed in no-tilled soils. Field glomalin-related soil protein content was reduced by tillage practices. Our multimodal approach, providing data on two main production factors affecting soil AMF communities, may help implementing effective agricultural management strategies able to support the beneficial relationship between crops and native AMF symbionts

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

Mycorrhizal activity and diversity in a long-term organic Mediterranean agroecosystem

In organic agriculture, soil fertility and productivity rely on biological processes carried out by soil microbes, which represent the key elements of agroecosystem functioning. Arbuscular mycorrhizal fungi (AMF), fundamental microorganisms for soil fertility, plant nutrition and health, may play an important role in organic agriculture by compensating for the reduced use of fertilizers and pesticides. Though, AMF activity and diversity following conversion from conventional to organic farming are poorly investigated. Here we studied AMF abundance, diversity and activity in short- and long-term organically and conventionally managed Mediterranean arable agroecosystems. Our results show that both AMF population activity, as assessed by the mycorrhizal inoculum potential (MIP) assay, the percentage of colonized root length of the field crop (maize) and glomalin-related soil protein (GRSP) content were higher in organically managed fields and increased with time since transition to organic farming. Here, we showed an increase of GRSP content in arable organic systems and a strong correlation with soil MIP values. The analysis of AMF spores showed differences among communities of the three microagroecosystems in terms of species richness and composition as suggested by a multivariate analysis. All our data indicate that AMF respond positively to the transition to organic farming by a progressive enhancement of their activity that seems independent from the species richness of the AMF communities. Our study contributes to the understanding of the effects of agricultural managements on AMF, which represent a promising tool for the implementation of sustainable agriculture