Increased attractiveness of honeybee hive product volatiles to adult small hive beetle, Aethina tumida, resulting from small hive beetle larval infestation

The small hive beetle, Aethina tumida Murray (Coleoptera: Nitidulidae), is a recent but significant pest of honeybee Apis mellifera L. (Hymenoptera: Apidae) hives in various regions throughout the world, including Eastern Australia. The larval stage of this beetle damages hives when they feed on brood, pollen, and honeycomb, leaving behind fermented wastes. In cases of extreme damage, hives collapse and are turned to an odorous mass of larvae in fermenting hive products. The yeast Kodamaea ohmeri (Etchells & Bell) Yamada et al. (Ascomycota) has been consistently isolated from the fermenting material as well as each life stage of this beetle. Various studies have noted that the small hive beetle is attracted to volatiles from hive products and those of the yeast K. ohmeri, although earlier studies have not used naturally occurring hive products as their source of fermentation. This study investigated changes through time in the attractiveness of natural honeybee hive products to the small hive beetle as the hive products were altered by the action of beetle larvae and fermentation by K. ohmeri. We used gas chromatography-mass spectrometry and choice-test behavioural assays to investigate these changes using products sampled from three apiaries. Attractiveness of the fermenting hive products (‘slime’) increased as fermentation progressed, and volatile profiles became more complex. Fermenting hive products remained extremely attractive for more than 30 days, significantly longer than previous reports. These results have strong implications for the development of an external attractant trap to assist in the management of this invasive pest

Increased attractiveness of honeybee hive product volatiles to adult small hive beetle, Aethina tumida, resulting from small hive beetle larval infestation

The small hive beetle, Aethina tumida Murray (Coleoptera: Nitidulidae), is a recent but significant pest of honeybee Apis mellifera L. (Hymenoptera: Apidae) hives in various regions throughout the world, including Eastern Australia. The larval stage of this beetle damages hives when they feed on brood, pollen, and honeycomb, leaving behind fermented wastes. In cases of extreme damage, hives collapse and are turned to an odorous mass of larvae in fermenting hive products. The yeast Kodamaea ohmeri (Etchells & Bell) Yamada et al. (Ascomycota) has been consistently isolated from the fermenting material as well as each life stage of this beetle. Various studies have noted that the small hive beetle is attracted to volatiles from hive products and those of the yeast K. ohmeri, although earlier studies have not used naturally occurring hive products as their source of fermentation. This study investigated changes through time in the attractiveness of natural honeybee hive products to the small hive beetle as the hive products were altered by the action of beetle larvae and fermentation by K. ohmeri. We used gas chromatography-mass spectrometry and choice-test behavioural assays to investigate these changes using products sampled from three apiaries. Attractiveness of the fermenting hive products (‘slime’) increased as fermentation progressed, and volatile profiles became more complex. Fermenting hive products remained extremely attractive for more than 30 days, significantly longer than previous reports. These results have strong implications for the development of an external attractant trap to assist in the management of this invasive pest

Small hive beetle, Aethina tumida (Coleoptera: Nitidulidae): chemical profile of the cuticle and possible chemical mimicry in a honeybee (Apis mellifera) pest

The small hive beetle, Aethina tumida (Coleoptera: Nitidulidae), is an economically important pest of the Western honeybee, Apis mellifera (Hymenoptera: Apidae). We investigated the effect of rearing environment on the cuticular chemical profile of adult A. tumida, using hexane to extract the hydrocarbons and other compounds from the cuticles of beetles. Beetles were collected from A. mellifera colonies in Australia as well as reared in single sex laboratory cultures on different diets. We investigated whether rearing environment (laboratory vs. field, different apiaries, access to mating partners, diet) had any effect on cuticular hydrocarbons. Coupled gas chromatography–mass spectrometry analyses of the extracts showed that rearing environment had significant qualitative and quantitative effects on the hydrocarbons detected. The data support the hypothesis that cuticular profiles of A. tumida are contingent on environment, partitioning on the basis of rearing diet and source hives. The finding has implications for the regulation of interactions between A. tumida and honeybees and improvements in targeting of management strategies

In-hive Fungal Biocontrol of Small Hive Beetle

The small hive beetle (SHB) (Aethina tumida), is a native scavenger of bee hives in South Africa where it is regarded as a minor pest. It was discovered in Australia in 2002. Since this time SHB populations have increased in number and range in the eastern states of Australia where in some areas they are causing significant losses. There is concern for even greater damage from this pest to the apiary industry in the warm moist regions of Australia if management practices to check its spread are not developed and implemented

Feasibility Study into In-Hive Fungal Bio-Control of Small Hive Beetle

The small hive beetle (Aethina tumida), a native to South Africa where is it only a minor pest, was discovered in Australia in 2002. Since this time small hive beetles have become an increasing problem in bee hives in the eastern states of Australia and appear to be spreading at a rapid rate. There is concern for even greater damage from this pest to the beekeeping industry in the warm moist regions of Australia where it can reproduce faster

Biological control of Giant Rat’s Tail grass utilising Nigrospora oryzae

Giant Rat's Tail grass (GRT) (Sporobolus pyramidalis and S. natalensis) has established itself as a significant problem to the profitability and sustainability of grazing environments across Eastern Australia. A combination of underutilisation by grazing animals due to unpalatability, resilience and persistence especially in poor soils, and an aggressively high seeding rate have seen GRT spread across many coastal and sub-coastal regions of Queensland. In some areas, GRT infestations have dramatically decreased livestock producers' economic viability and lowered their land values. Current infestations are collectively costing the pastoral industry in the vicinity of $60 million per annum through lost production and control (Bray and Officer, 2007). In many cases, the stocking rates have been halved on pastures heavily infested with GRT. In addition, the age of turn off of fat cattle on these pastures has been extended by up to 12 months (Bray 2008). The potential area of infestation in Queensland covers 108 million hectares or 60% of Queensland (Anon, 1999). This project investigated the ability of the fungus Nigrospora oryza to cause die back in GRT and subsequent potential as a biocontrol agent of GRT. This fungus has been proposed as a pathogen of Giant Parramatta Grass (GPG) (S. fertilis), a closely related species to GRT

Aiming for the management of the small hive beetle, Aethina tumida, using relative humidity and diatomaceous earth

Small hive beetles (SHBs) are a global pest of European honeybee colonies. In the laboratory, the survival of adult SHBs was evaluated in relation to relative humidity (RH = 56, 64, 73, 82 and 96 %) and treatment with diatomaceous earth (DE) across 4 days. Low RH reduced survival. The application of DE reduced survival in addition to RH. Adults treated with corn flour (control) showed no difference in survival from untreated beetles. Scanning electron microscopy images showed no scarification of adult beetle cuticle after exposure to DE; therefore, water loss is likely facilitated through non-abrasive means such as the adsorption of cuticular lipids. The data agree with the hypothesis that DE causes mortality through water loss from treated insects. Egress, ingress, mortality and the egg-laying behaviours of beetles were observed in relation to a popular in-hive trench trap with and without the addition of DE. Traps filled with DE resulted in 100 % mortality of beetles compared with 8.6 % mortality when no DE was present. A simple method for visually determining beetle sex was used and documented

Development of mycoinsecticide formulations with Beauveria bassiana and Metarhizium anisopliae for the control of lesser mealworm, Alphitobius diaperinus, in chicken broiler houses

Entomopathogenic fungi are promising alternatives to synthetic chemicals for controlling lesser mealworm populations in broiler houses. Granular formulations of two isolates of the fungi Beauveria bassiana and Metarhizium anisopliae based on ground chicken feed pellets produced 98 and 87% larval mortality, respectively, after 11 days’ exposure to ≈ 0.2 g conidia/54 g formulation m−2 in the laboratory. Oil based formulations with canola oil and Codacide™ were generally slower to produce mortality but still significantly effective. Granular formulations were effective on a range of broiler-house substrates (new and used litter, soil) of varying pH and moisture content. The efficacy of the M. anisopliae isolate appeared enhanced and the B. bassiana isolate inhibited on damp new litter (40% moisture). Substrate pH (3.45–6.38) did not discernibly inhibit fungal efficacy. Granular formulations of both fungal isolates tested at average broiler-house temperatures were ineffective at 35 °C but became active when re-tested at 30 °C. Granular mycoinsecticide formulations based on the two isolates are now ready for testing in commercial broiler houses

Optimal placement of fast charging stations of electric vehicles using genetic algorithm and power flow

128 σ.Στις μέρες μας ο πληθυσμός των ηλεκτρικών οχημάτων παρουσιάζει ραγδαία αύξηση παγκοσμίως, κυρίως λόγω της φιλικότητάς τους προς το περιβάλλον και του χαμηλότερου κόστους καθημερινής χρήσης σε σχέση με τα οχήματα που λειτουργούν με συμβατικά καύσιμα. Ωστόσο, υπάρχει η ανάγκη δημιουργίας των κατάλληλων υποδομών φόρτισης έτσι ώστε να επιτευχθεί η αυξανόμενη διείσδυση των ηλεκτρικών οχημάτων στην παγκόσμια αγορά. Επομένως, η κατάλληλη τοποθέτηση των Σταθμών Ταχείας Φόρτισης (ΣΤΦ) ηλεκτρικών οχημάτων και των Μονάδων Διεσπαρμένης Παραγωγής (ΜΔΠ) σε ένα δίκτυο διανομής, είναι υψίστης σημασίας προκειμένου να μεγιστοποιηθούν τα οφέλη που προκύπτουν από την ένταξή τους στο δίκτυο. Σκοπό της παρούσας διπλωματικής εργασίας αποτελεί αρχικά, η εύρεση της βέλτιστης θέσης εγκατάστασης των Μονάδων Διεσπαρμένης Παραγωγής και στη συνέχεια της βέλτιστης θέσης εγκατάστασης των Σταθμών Ταχείας Φόρτισης ηλεκτρικών οχημάτων σε ένα δίκτυο διανομής με βάση τεχνικά κριτήρια. Η εύρεση αυτών των βέλτιστων θέσεων, επιτυγχάνεται μέσω της χρήσης του Γενετικού Αλγορίθμου (ΓΑ) σε συνδυασμό με τη Ροή Φορτίου (ΡΦ) και τη Βέλτιστη Ροή Φορτίου (ΒΡΦ). Πιο συγκεκριμένα, μέσω της βέλτιστης τοποθέτησης των Σταθμών Ταχείας Φόρτισης στο δίκτυο επιδιώκεται η ελαχιστοποίηση των απωλειών ενεργού ισχύος και η βελτίωση του προφίλ τάσης. Στα πλαίσια της παρούσας εργασίας, υλοποιήθηκε αλγόριθμος σε περιβάλλον MATLAB, που επιλύει τα εν λόγω προβλήματα χρησιμοποιώντας και κάποια στοιχεία από το λογισμικό πακέτο MATPOWER το οποίο είναι λογισμικό σε MATLAB και υπολογίζει Ροές Φορτίου και Βέλτιστες Ροές Φορτίου. Στο Κεφάλαιο 1 αυτής της εργασίας γίνεται αναφορά στη Διεσπαρμένη Παραγωγή (ΔΠ), παρουσιάζοντας τα βασικότερα είδη διεσπαρμένων πηγών, τις χρήσεις, τα πλεονεκτήματα και τα μειονεκτήματά τους. Ακόμα, γίνεται μια εισαγωγή στα ηλεκτρικά οχήματα και τους σταθμούς φόρτισης, παρουσιάζονται οι τεχνολογίες των ηλεκτρικών οχημάτων, οι κατηγορίες και τα επίπεδα φόρτισής τους και παραθέτονται τα πλεονεκτήματα και τα μειονεκτήματα της διείσδυσής τους στην παγκόσμια αγορά. Στο Κεφάλαιο 2 περιγράφεται ο Γενετικός Αλγόριθμος και παρουσιάζονται τα βασικά μέρη από τα οποία αποτελείται. Στο Κεφάλαιο 3 αναλύεται το πρόβλημα της Ροής Φορτίου και της Βέλτιστης Ροής Φορτίου και ακόμα παρουσιάζεται το λογισμικό MATPOWER που χρησιμοποιήθηκε για την εκτέλεση αυτών των δύο ροών. Στο Κεφάλαιο 4 παρουσιάζεται η διατύπωση των προβλημάτων, ενώ στο Κεφάλαιο 5 παραθέτονται τα αποτελέσματα των προσομοιώσεων που υλοποιήθηκαν για την βέλτιστη εγκατάσταση των Μονάδων Διεσπαρμένης Παραγωγής και των Σταθμών Ταχείας Φόρτισης. Ακόμα, στο ίδιο κεφάλαιο μελετάται και η ανάλυση ευαισθησίας του αλγορίθμου. Τέλος, στο Κεφάλαιο 6 συνοψίζονται τα κυριότερα συμπεράσματα που προέκυψαν από αυτή την ανάλυση.Nowadays the population of electric vehicles has been increasing rapidly worldwide, mainly because of their friendliness to the environment and their lower cost of daily use compared to vehicles which use conventional fuels. However, there is a need to create the appropriate charging infrastructures in order to achieve increased penetration of electric vehicles. Therefore, the optimal placement of Fast Charging Stations (FCS) and of Distributed Generation Units (DGU) in a distribution grid, is crucial in order to maximize the benefits derived from their joining the grid. The aim of the present thesis is initially to find the optimal location of Distributed Generation Units and then the optimal location of Fast Charging Stations in a distribution grid, based on technical criteria. Finding these optimal locations, is being achieved by utilizing the Genetic Algorithm (GA) in conjunction with Power Flow (PF) and Optimal Power Flow (OPF). More precisely, this thesis through optimal placement of charging stations in the grid seeks to minimize the active power losses and improve the voltage profile. As part of this diploma thesis, an algorithm in MATLAB environment was implemented in order to solve these problems, by using some features of the MATPOWER suite which is a software in MATLAB and it calculates Power Flows and Optimal Power Flows. Chapter 1 of this thesis refers to Distributed Generation (DG), by presenting an overview of the main types of distributed resources, their use, their advantages and disadvantages. In addition, this chapter gives an introduction to electric vehicles and charging stations, presents the technologies of electric vehicles, the categories and levels of charging and lists the advantages and disadvantages of their penetration in the global market. Chapter 2 describes the Genetic Algorithm and presents the main parts of which it is composed. Chapter 3 analyzes the problem of Power Flow and Optimal Power Flow and even presents the MATPOWER suite which was used to perform these two flows. Chapter 4 presents the formulation of these problems, while Chapter 5 lists the results of simulations carried out for the optimal placement of Distributed Generation Units and Fast Charging Stations. Furthermore, the same chapter performs a sensitivity analysis of the algorithm. Finally, Chapter 6 summarizes the main conclusions drawn from this analysis.Σωτήριος Γ. Θανόπουλο

Small hive beetle (Coleoptera: Nitidulidae) and the yeast, Kodamaea ohmeri: a facultative relationship under laboratory conditions

The small hive beetle, Aethina tumida Murray, is a pest of honeybees, Apis mellifera L. (Hymenoptera: Apidae). We investigated the significance of its association with the yeast, Kodamaea ohmeri (Etchells & Bell) (Ascomycota: Saccharomycotina), in laboratory experiments. The mean (± SEM) viability of A. tumida eggs was 84 (± 3)%; the viability was not affected if eggs were separated from clutches or if mucilage containing K. ohmeri was removed from the egg surface. Life tables of conventional (= K. ohmeri contaminated) A. tumida and K. ohmeri-free A. tumida revealed no differences in stage-specific mortality between the treatments; in both cases, the highest mortality occurred in the first larval instar. There was no significant difference in the initial egg production of conventionally reared and K. ohmeri-free A. tumida under laboratory conditions. The volatile profiles of pollen dough (Bee Build) fed on by conventional and K. ohmeri-free A. tumida larvae were qualitatively and quantitatively different; the volatiles produced by pollen dough fed on by conventional A. tumida were more attractive to adult beetles. There was a clear difference between growth of K. ohmeri on pollen dough substrate in the presence and absence of A. tumida. Results suggest that this association is facultative for A. tumida under laboratory conditions but has benefit for the yeast associate, K. ohmeri. A clearer understanding of the nature of this fungus-insect association is essential for the development of management strategies for this pest, especially in the development of fermentate-based attractants in trapping systems