Xylosandrus compactus (Eichhoff, 1876) (Coleoptera, Curculionidae, Scolytinae) and Stephanitis lauri Rietchel, 2014 (Hemiptera, Tingidae): two exotic species that have spread throughout the drainage basin in the stream of Tossa (La Selva, Girona, NE Spain)

Abstract

In the monitoring carried out in the drainage basin of Tossa de Mar (Girona province, NE Spain), with 39 km2, 2 streams and 20 smaller streams, attacks by the ambrosia beetle Xylosandrus compactus (Eichhoff, 1876) (Coleoptera, Curculionidae, Scolytinae) have been found on 22 plant species within the forest ecosystem, mostly in riparian vegetation. The most affected host plant has been laurel (Laurus nobilis, observed in 54.4 % of the infested points) and much less frequently alders (Alnus glutinosa; 7.6 %), elms (Ulmus minor; 6 .3 %), hazelnuts (Corylus avellana; 6.3 %) and cherries (Prunus avium; 5.7 %). This ambrosia beetle has been found in 107 points in the basin, from 3 to 432 masl in the highest section of the Aiguafina stream. On the other hand, the laurel lace bug Stephanitis lauri Rietchel, 2014 (Hemiptera, Tingidae) has shown a much higher attacking level and much more widespread distribution in the laurels of the two streams and the smaller streams of the basin. Since the first detections in Catalonia, in the summer of 2020 in Banyoles (for X. compactus) and in Lloret de Mar (for S. lauri), these two exotic species have had a fast spread throughout several regions in the provinces of Girona and Barcelona, with great colonizing and invasive capacities, as expected of species considered pests. There has to be a great concerning for these dangerous situations. Warning about the negative future prospects of the laurel in the forest ecosystems, in riparian and ravine vegetation, as well as plant community in laurel forests and laurisilvas should be made.