Endosymbiotic bacteria in the genus Wolbachia have been linked to several types of reproductive parasitism, which enhance their own transmission, while their direct effects on the host vary from beneficial to neutral or detrimental. Here, we report negative effects of infection on immunity-related traits of Drosophila simulans and the parasitoid wasp Leptopilina heterotoma. Infected D. simulans showed a reduced ability to encapsulate parasitoid eggs, compared to a tetracycline-treated, bacterium-free line. Challenging the two lines with a fungal pathogen, Beauveria bassiana, on the other hand, revealed no differences in survival. Moreover, elimination of Wolbachia was beneficial for the parasitoid wasp, as eggs laid by uninfected females suffered significantly lower encapsulation rates. We discuss possible origins of these fitness costs and their implications for infection dynamics and the interactions between host species.

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Intensive crop production and irrational use of fertilizers and agrochemicals have questionable effects on the quality of products and the sustainable use of water for agricultural purposes. Organic cultivation and/or deficit irrigation are, among others, well appreciated practices for a sustainable crop production system. In the present study, spearmint plants (Mentha spicata L.) were grown in different cultivation schemes (conventional versus organic cultivation, full versus deficit irrigation), and effects on the plant physiological and biochemical attributes were examined in two harvesting periods. Deficit irrigation decreased plant growth, but increased total phenolics, flavonoids, and antioxidant capacity of the plants at the second harvest. Spearmint nutrient accumulation was affected by the examined cultivation practices; nitrogen was decreased in organic cultivation, potassium and sodium were elevated at full-irrigated plants, while magnesium, phosphorus, and copper levels were higher at the deficit-irrigated plants. However, conventional/full-irrigated plants had increased height and fresh biomass at the first harvest. Essential oil content decreased at the second harvest in organic and/or deficit treated plants. Additionally, deficit irrigation affected plant growth and delayed the formation of carvone from limonene. The essential oils were further evaluated with regard to their bioactivity on a major vineyard pest Lobesia botrana. Volatile compounds from all essential oils elicited strong electroantennographic responses on female insects antennae, highlighting the role of carvone, which is the major constituent (~70%) in all the tested essential oils. M. spicata essential oils also exhibited larvicidal activity on L. botrana, suggesting the potential of their incorporation in integrated pest management systems.

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Human cases of West Nile virus (WNV) infections have been recorded in Greece since 2010, with seasonal outbreaks (summer-autumn) on an almost annual basis, caused mainly by the WNV lineage 2 strain (Nea Santa-Greece-2010). National Public Health Organization (NPHO) in Greece is annually implementing enhanced surveillance of human WNV infection, in order to promptly identify human cases of WNV infection and monitor distribution in terms of time and place. Entomological surveillance activities were carried out on a national basis in 2019 and 2020, under NPHO coordination and the collaboration of several private subcontractors, along with the Unit of Medical Entomology, Laboratory for Surveillance of Infectious Diseases (LSID). The aim was to monitor mosquito species composition, abundance, and WNV circulation in mosquito pools of Culex pipiens s.l. species. Adult mosquito traps were placed in selected sites; collected samples were morphologically characterized and pooled by date of collection, location, and species types. Female Culex pipiens s.l. pools were tested for WNV and WNV infection rates (MIR and MLE) were estimated. Highest mean number of female Culex pipiens s.l. species was recorded in Central Macedonia both for 2019 and 2020. Six hundred and fifty-nine mosquito pools (147 in 2019 and 512 in 2020) of female Culex pipiens s.l. were examined for WNV presence. The highest MLE was detected in Western Macedonia in 2019 and in Thessaly in 2020. Here, we present data on the mosquito species composition in the studied areas and WNV detection in mosquitoes from areas in Greece where the specific national mosquito surveillance program was implemented, for two years, 2019 and 2020.