Monitoring of phytophagous hemipteran species from the main parks of Timisoara.
Based on the observations from the last two years, on the plants present in the parks near the central area of Timisoara, we decided to focus on phytophagous insect species of the order Hemiptera. This order considered in this paper are represented by stink bugs, seed bugs from Coreidae, aphids and flatid planthoppers. The reason why we focused on this category of insects was primarily based on the analysis of recent years and implicitly their increasing evolution, also on the attention paid to dangerous invasive species. Lately, they have started to be more and more present in big cities and especially in green spaces, parks and gardens, usually near people's houses or near buildings. Observations were made directly in the parks, approaching an adapted methodology, by dividing each park into sectors and establishing observation points. The study periods were April 1, 2019 - September 30, 2019 and April 1, 2020 - September 30, 2020. Depending on the species, the stage observed at a given time (during predetermined periodic readings) was either in the adult or larval or nymph level or both. Also, the plants subject to observation were grassy and/or woody depending on their presence in the analyzed sector/park. Thus, by periodically monitoring five main parks in the city of Timisoara, we found that there are differences between them in terms of identified species, population level and damage to plants. Some species of Hemiptera (Metcalfa pruinosa. Nezara viridula, Aphis sp. and Eriosoma lanigerum) have been present in high and medium populations and others (such as Leptoglosus occidentalis) in smaller populations. Of the species present, the following species have been identified as invasive ones, namely Metcalfa pruinosa, Nezara viridula and Halyomorpha halys. The aggressiveness of harmful insects on ornamental plants was described in terms of the level of abundance and symptoms observed. In conclusion, through the monitoring activity, which is a continuous update depending on numerous external factors and in the context of climate change, new dangerous species can be identified and new management solutions can be taken.