728 research outputs found

    Invasive Wood Borers: Detection, Establishment and Spread

    Get PDF
    The increasing international trade occurred in the last decades has raised the risk of introduction of invasive species. These are organisms introduced in new environments located out of their native area. Plants and insects represent the most common invasive species. Concerning insects, wood borers are the most important for forest ecosystems. Introductions of invasive alien species have strong ecological and economic effects on native fauna and their interception and eradication are prior goals. In the present work, the Asian longhorned beetle, Anoplophora glabripennis (Motschulsky), recently discovered in north Italy has been considered. This longhorned beetle is a threat for temperate forests of the northern hemisphere, accounting many infestation sites in Europe and North America. The rich literature, its biological characteristics and the wide distribution makes of A. glabripennis an appropriate model species. The thesis is divided into four main parts: the first (chapter 1) is an introduction about invasive species with special attention on A. glabripennis, providing the knowledge for understanding the following chapters. The second part (chapter 2) investigated the beetle introduction and spreading pathways in the infestation site through a dendrochronological study of the infested plants, identifying the oldest spot and the possible causes of introduction. The third part is composed of three chapters (3-4-5) focused on establishment into a new environment and adaptation to novel hosts, analysing the interactions between different environments and host preference. Chapter 3 studies insect phenology and life history in N Italy. Chapter 4 investigates the host-plant preferences. Effect of habitats and host plants is addressed in chapter 5, where the colonization failure of forest areas nearby the infestation is investigated. A last part (chapter 6) presents an analyses of the adult dispersal, developing an approach based on the probability of attack from an attacked host to an healthy one. The study contributes on the global knowledge of Anoplophora glabripennis, providing data from a new infestation area. Moreover, it looks for plausible explanation of species traits, such as the variation on host preference between populations. Finally, it is proposed a new approach to dispersal evaluation, which can be developed also on other invasive organisms

    The Cuticular Hydrocarbons of Dasineura Oleae Show Differences Between Sex, Adult Age and Mating Status

    Get PDF
    : In insects, cuticular lipids prevent water loss and act as semiochemicals. Because of their ecological function, the profile change across the insects' sex and development offers insight into insect biology and possible tools for pest management. Here, the first work on cecidomyiid cuticular extracts is proposed considering Dasineura oleae (Diptera: Cecidomyiidae) males and females at different adult ages (0-12 h, 12-24 h, 24-36 h) and distinct sexual conditions (virgin and mated). A set of 49 compounds were recorded (12 alkanes, 1 monomethyl alkane, 11 fatty acids, 4 esters, 1 aldehyde, 1 allylbenzene, 1 amine, 1 flavonoid, 1 ketone, 1 phenol, 1 steradiene, 1 sterol, 1 terpene, 1 triterpene and 11 unknown compounds), and 18 of them showed significant differences between groups. Among alkanes, hexacosane (nC26) exhibited a decreasing trend from the youngest to the oldest females, while pentacosane (nC25) and nonacosane (nC29) showed a decreasing trend from 0 to 12 h to 12-24 h virgin females. In addition, nonadecane (nC19) was significantly more abundant in the youngest males compared to older males and females. The alkanes nC25, nC26 and nC29 have been reported to be age-related also in other dipterans, while nC19 has been described as gender-specific chemical cue for platygastrid parasitoids. Further behavioural trials and analyses are required to assign the specific ecological roles to the characterized compounds. Our results may contribute to develop new low-impact control strategies relying on the manipulation of D. oleae's chemical communication (e.g. disruption of mating or species recognition). HIGHLIGHTS: • Cuticular hydrocarbons are often involved in dipteran intraspecific communication. • We explored the cuticular profile of D. oleae at different age, sex, mating condition. • Five alkanes and one mono-methyl alkane showed differences among groups. • Linoleic acid is the most abundant compound in virgins, absent in mated insects. • Eleven compounds disappear in mated insects, but were present in all virgins

    An artificial diet for rearing three exotic longhorn beetles invasive to Europe

    Get PDF
    Anoplophora glabripennis, Anoplophora chinensis and Psacothea hilaris hilaris are three invasive exotic longhorn species (Coleoptera Cerambycidae) threatening native broadleaf trees in Europe and North America. Field studies on invasive species are somewhat difficult in the areas of introduction due to the application of eradication measures and the activation of quarantine protocols. Rearing these species in standard laboratory conditions would allow specific ecological and biological investigations to be conducted. In this paper, the rearing of these longhorn beetles has been tested on an artificial diet in laboratory conditions. The tested diet can be used to obtain viable healthy adults of each of the three studied species. P. h. hilaris had the best rearing performance with 74% of eggs producing new adults, while A. chinensis and A. glabripennis were poorer with 24.7% and 23.3%, respectively. The low percentage of emerging A. glabripennis and A. chinensis adults was due mainly to a high mortality of their first instar larvae not entering the diet. Moreover, A. chinensis and A. glabripennis had a mean development time, 60.06 and 37.29 weeks, respectively (including the chilling periods required for pupation), longer than P. h. hilaris (16.1 weeks). During development, larval moults varied according to species and within species ranging from 5-7 (P. h. hilaris), 6-11 (A. chinensis) and 7-8 (A. glabripennis) moults, respectively. Adults of A. glabripennis and P. h. hilaris reared on the diet were bigger than wild specimens collected from the same population, whereas A. chinensis adults were smaller. Adult survival was shorter in A. glabripennis (62.9 days) than in P. h. hilaris (119.3 days). According to the different performance of the three species, the rearing costs were about 2.0, 8.1 and 16.1 US dollars per adult beetle for P. h. hilaris, A. glabripennis and A. chinensis, respectively. A laboratory insect population has to be cost effective and self-sustainable over time, and the tested diet provided valuable results for the low-cost mass rearing of these invasive longhorn beetles

    Developing female removal for Cydia pomonella (Lepidoptera: Tortricidae) in organic pear in the USA and Italy

    Get PDF
    AbstractSeventeen trials were conducted using traps baited with kairomone‐based lures to evaluate female removal (FR) as an effective management tactic for codling moth, Cydia pomonella, L., in organic pear, Pyrus communis L., production in Italy and USA during 2019–2020. Studies included paired plots (0.4–1.4 ha) treated with or without 60 traps ha−1 in cultivars Bartlett and Abate Fétel. Paired plots were also treated together with or without mating disruption (MD) and with similar spray programmes. Three‐, four‐, and five‐component lures were used with several trap types: green, clear or green/white bucket traps and orange delta traps. The three‐component lure consisted of (E,E)‐8,10‐dodecadien‐1‐ol (sex pheromone, PH), (E,Z)‐2,4‐ethyl decadienoate (pear ester, PE) and acetic acid (AA); the four‐component lure was PE, (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT), 6‐ethenyl‐2,2,6‐trimethyloxan‐3‐ol (pyranoid linalool oxide, LOX), and AA, and the five‐component lure had PH added. Preliminary studies were also conducted to evaluate the trapping efficacy of non‐saturating bucket traps. A clear bucket trap baited with PE/DMNT/LOX + AA captured 97‐fold more codling moth females than an orange delta trap baited with PH/PE. However, female captures did not differ between traps when both were baited with the four‐component lure. Fruit injury from codling moth was significantly reduced with the implementation of FR in both pear production regions. At harvest, mean fruit protection in the USA studies was 65% and 27% in Italy. This difference was likely associated with the four‐component lure being less effective in Italy than in the USA. Nevertheless, results demonstrate that FR can be a useful approach to remove females immigrating into orchards and as a new tactic to reduce pest pressure in selected areas of orchards allowing both MD and organic insecticide programmes to be more effective. Further studies should investigate the cost‐benefit of matching the intensity of FR to variable pest pressures

    Combined effect of a neonicotinoid insecticide and a fungicide on honeybee gut epithelium and microbiota, adult survival, colony strength and foraging preferences

    Get PDF
    Fungicides, insecticides and herbicides are widely used in agriculture to counteract pathogens and pests. Several of these molecules are toxic to non-target organisms such as pollinators and their lethal dose can be lowered if applied as a mixture. They can cause large and unpredictable problems, spanning from behavioural changes to alterations in the gut. The present work aimed at understanding the synergistic effects on honeybees of a combined in-hive exposure to sub-lethal doses of the insecticide thiacloprid and the fungicide penconazole. A multidisciplinary approach was used: honeybee mortality upon exposure was initially tested in cage, and the colonies development monitored. Morphological and ultrastructural analyses via light and transmission electron microscopy were carried out on the gut of larvae and forager honeybees. Moreover, the main pollen foraging sources and the fungal gut microbiota were studied using Next Generation Sequencing; the gut core bacterial taxa were quantified via qPCR. The mortality test showed a negative effect on honeybee survival when exposed to agrochemicals and their mixture in cage but not confirmed at colony level. Microscopy analyses on the gut epithelium indicated no appreciable morphological changes in larvae, newly emerged and forager honeybees exposed in field to the agrochemicals. Nevertheless, the gut microbial profile showed a reduction of Bombilactobacillus and an increase of Lactobacillus and total fungi upon mixture application. Finally, we highlighted for the first time a significant honeybee diet change after pesticide exposure: penconazole, alone or in mixture, significantly altered the pollen foraging preference, with honeybees preferring Hedera pollen. Overall, our in-hive results showed no severe effects upon administration of sublethal doses of thiacloprid and penconazole but indicate a change in honeybees foraging preference. A possible explanation can be that the different nutritional profile of the pollen may offer better recovery chances to honeybees

    Reproductive biology of Sclerodermus brevicornis, a European parasitoid developing on three species of invasive longhorn beetles

    Get PDF
    The reproductive performance of Sclerodermus brevicornis (Kieffer), a bethylid wasp native to Europe, was evaluated on three species of facticious hosts. These are longhorn beetles which have recently invaded Europe from Asia: Anoplophora glabripennis (Motschulsky), Anoplophora chinensis (Forster) and Psacothea hilaris hilaris (Pascoe) (Coleoptera: Cerambycidae). Sclerodermus brevicornis attacked all three species, but offspring only developed to maturity on medium and large sized host larvae. Host species influenced the duration of parasitoid development and the number of offspring maturing, both were greatest on A. glabripennis, with up to 373 adult parasitoids emerging from a single host. The sex ratios of S. brevicornis broods were strongly female biased (ca. 9% males). We conclude that S. brevicornis has the potential to be efficiently mass-reared and actively deployed in the biological control of invasive longhorn beetles. Further progress should be encouraged by the successful use of other species of Sclerodermus against beetle pests in China

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

    Full text link
    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

    Get PDF
    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

    Search for stop and higgsino production using diphoton Higgs boson decays

    Get PDF
    Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass
    corecore