https://www.um.edu.mt/library/oar/handle/123456789/114784 2026-05-07T12:52:34Z https://www.um.edu.mt/library/oar/handle/123456789/118076 Title: A taxonomic study of the thrips (Thysanoptera) of the Maltese Islands Abstract: The thrips (Thysanoptera) of the Maltese Islands have so far been very little studied, with the few existing works focusing on species of agricultural importance. The current study has investigated the biodiversity of thrips species of the Maltese Islands, discriminated between these species by means of a simple illustrated identification key and investigated their feeding habits and geographical distribution. Thrips were collected from 252 indigenous and 146 cultivated plant species and subsequently mounted individually on glass slides to be identified. Literature describing 691 species from the Palaearctic region was consulted to help select which plants to sample for thrips. Online and printed identification keys were used to identify the species. Specimen photos were then sent to world thrips experts to confirm identification. One of these experts, Dr Arturo Goldarazena, inspected the collection of thrips amassed during the current study to help identify species of the genera Haplothrips, Karnyothrips and Odontothrips. In all, 53 species were identified to species level. One species under the genus Karnyothrips is a possible new record to science. Following literature, 48 of the locally recorded species are phytophagous, with six of these being facultative predators, while three species mycophagous and two being obligate predators. Chorological data for the species in the Maltese Islands revealed that 23 species are of cosmopolitan or subcosmopolitan distribution, while 25 species are found across Europe and the Mediterranean region. Nine are alien species, very likely introduced with imported crops and cultivars, since they were not recorded on indigenous plants. These species could affect the local agricultural scenario, even though locally they were found in numbers too small for these thrips to be considered pests. The current study recommends further investigation of the agricultural impact of thrips species in the Maltese Islands, as well of thrips which may be introduced with locally imported plant material. Further research on the species that could not be identified to species level, as well as on the possible new species of Karnyothrips are also recommended. Description: Ph.D.(Melit.) 2023-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/115725 Title: Pollen characterization of honey from Apis mellifera ruttneri and Apis mellifera buckfast : a case study from Malta Abstract: Melissopalynology is an important field of study that focuses on the evaluation of pollen found in honey. Since these grains vary in structure, this method of analysis can trace back to which vegetation they belong to, ultimately shedding light on the foraging trends or plant preferences of the honeybees (Apis mellifera). Despite its importance, limited literature exists on the Maltese islands regarding which vegetation is preferred by the endemic honeybee, Apis mellifera ruttneri, leading to an absence of conservancy. The constant hybridisation and importation of other honeybees, such as Apis mellifera buckfast, have also accelerated its endangerment status. This study has found the similarities and lack thereof between the foraging preferences of the two Apis mellifera subspecies residing in Wardija, by analysing 18 honey samples. A standard extraction procedure was used to prepare the samples for microscope analysis for the purpose of pollen identification and quantification. Following this, the pollen was then characterised using cluster analysis. It was found that the subspecies foraged on similar floral families, namely Fabaceae and Asteraceae, but differ at the vegetation-type level. The ruttneri honeybees showed a preference for Hedysarum-type flora while the buckfast had high counts of Vicia sativa and Lotus-type flora, and overall had a higher number of pollen grains in their honey. The latter subspecies showed a lot more clustering than the endemic kind, suggesting that their overall flora selection was not as varied. This research has only provided pollen trends found in honey obtained from one area during one season, therefore further studies would need to be conducted to confirm these findings. Description: B.Sc. (Hons)(Melit.) 2023-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/115724 Title: Comparing water pollution levels in various irrigation sources used for agriculture around different locations in the Maltese Islands Abstract: This project aimed to compare water quality in different Districts of Malta and assess the water sources used for agriculture. Water samples were analysed to identify potential contaminants and classify the Districts based on water quality. The study also examined the impact of water quality on agricultural practices and farmers' concerns. The findings provide insights into water quality, its impact on agriculture, and the perspectives of farmers. The study focused on variables such as pH, electrical conductivity, chlorides, and nitrates, which are crucial for crop selection and irrigation. Thirty-six samples were collected from the Six Districts, with variable agricultural holdings. Borehole water emerged as the primary irrigation source, followed by rainwater and spring water. Illegal boreholes were identified as issues. Drip irrigation was the most common irrigation method used, offering efficiency and water conservation. Market gardening and potato crops were found to be the most water intensive. The study also revealed variances in organic farming practices. Some water quality issues reported by farmers, included salinity and high nitrate levels. Corrective measures were noted. pH and conductivity analysis showed variations in different water sources. Rainwater had lower conductivity and chlorides compared to borehole and spring water. Nitrate pollution was a major concern, with most samples exceeding the EU limit. Correlation analysis highlighted relationships between conductivity, chloride, nitrate, and pH. Principal Component Analysis provided insights into sample clustering based on water source and region. Overall, the project provides information for improving water quality and better agricultural sustainability in Malta. Description: B.Sc. (Hons)(Melit.) 2023-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/115723 Title: Monitoring ‘Ceratonia siliqua’ L. pollen in Malta Abstract: Climate change will impact different interconnected global systems; therefore, it is important to monitor indicators of these changes in order to further understand and predict the implications of climate change. Plants being known bioindicators, may phenologically be altered in response to climate change, and thus have been one of the subjects of climate change research. Aerobiology has been a growing interdisciplinary field that may be utilised to monitor the phenological changes in plants in connection to its pollen release. The carob tree, Ceratonia siliqua, being native to the Mediterranean, has certain adaptations that may allow it to be more resistant to changes that will be further exacerbated by climate change. With interests in the species contributing to sustainable development in the region, monitoring its phenological changes would benefit the carob industry. This project investigated the pollen season and concentration of C. siliqua and aimed at contributing to the limited aerobiological research in Malta. This was done through utilising the Burkard trap, alongside passive capturing and ground truthing. The results obtained shows that the carob season for Autumn 2022 in the region was from 2nd of October to the 21st of November. Furthermore, C. siliqua pollen concentrations showed weak correlations with the meteorological parameters, namely mean temperature, precipitation, relative humidity and wind speed. However, long-term data would be required to interpret these correlations as several other factors were not considered. This project can be used as a baseline for future aerobiological research, in order to understand the impact that our changing climate will have on the species. Description: B.Sc. (Hons)(Melit.) 2023-01-01T00:00:00Z