1. Leopold Poljaković-Pajnik , Institute of Lowland Forestry and Environment Novi Sad, University of Novi Sad, Serbia
2. Milan Drekić , Institute of Lowland Forestry and Environment Novi Sad, University of Novi Sad, Serbia, Serbia
3. Andrej Pilipović , Institute of Lowland Forestry and Environment Novi Sad, University of Novi Sad, Serbia
4. Nataša Nikolić , Faculty of Sciences, University of Novi Sad, , Serbia
5. Saša Orlović, Institute of Lowland Forestry and Environment, University of Novi Sad, Serbia
6. Verica Vasić , Institute of Lowland Forestry and Environment Novi Sad, University of Novi Sad, Serbia
The oak lace bug originates from North America, and was first recorded in Europe in 2000 in Italy. In Turkey it was recorded in 2003. In the Balkans, it occurred in Bulgaria in 2012, while in Serbia firs finding was in 2013 around the town of Jamena in Srem. Although this insect is a weak flier, it is rapidly spreading through the wind. A typical symptom of an attack is the appearance of a change in the leaves that that manifest in discoloration and wilting. Nutrition on the oak causes drying and early decay of leaves what can increase sensitivity to other insects, diseases or the effects of pollutants. The damage is particularly pronounced in the stands of oak forests in the forests that are being managed by ŠG Sremska Mitrovica (JP Vojvodinašume), where in 2015 the total attack area was almost 27,000 hectares.
The distribution of Corythucha arcuata on oak forests in Vojvodina was investigated during 2016 and 2017 with a total of 27 sites examined across the province. The presence is recorded on the basis of the established stages of the larvae or the adults on the leaves of oak trees.
Investigations related to the influence of oak lace bug on the physiological processes in the plants were carried out in the oak stand, located in the area where the PE Vojvodinašume farm, ŠG Sremska Mitrovica, ŠU Morović, GJ Vinična - Žeravinac - Puk. Due to the large spread of pests on all age groups of the planting stock, as well as due to the easier accessibility of the attacked leaves, measurements were performed in the regenerated young stand.
Out of a total of 27 sites where the presence of oak lace bug was investigated, it was found at 20 locations, while seven sites had no records on the insect. It was found in the oak stands, nurseries, parks and avenues in the largest part of Vojvodina, except for Eastern and Southern Banat, where it has not yet been found. The largest and most valuable complexes of the oak stands are located along the river Sava in Srem and along the Danube in Bačka (Gornje Podunavlje) were colonized by this introduced species, which is already causing significant damage to the cultivation of oak and requires the implementation of protection measures.
Investigations of the impact of oak lace bug on photosynthetic processes have shown that the attack leads to a decrease in photosynthesis intensity and transpiration in leves. The decrease in the intensity of the net photosynthesis in the affected leaves was as high as 59%, while the transpiration was reduced up to 22%.
The difference in fluorescence between colonized and non-colonized leaves was also studied and statistically significant differences were found.