Brijestova osa listarica (Aproceros leucopoda; Hymenoptera, Argidae) je nova invazivna vrsta koja se širi Europom. Porijeklom je iz Japana, a prvi nalaz u Europi zabilježen je 2003. U članku se daje prikaz biologije i štetnosti brijestove ose listarice, lokaliteti prvog nalaza i prognozira se njezino širenje i štete u Hrvatskoj. Potencijalni domaćini u Europi su sve autohtone i alohtone vrste brijesta i njihovi kultivari. Vrsta ima četiri generacije godišnje, razmnožava se partenogenezom, a ličinke stvaraju tipične i lako prepoznatljive tragove na listu, karakteristični cik-cak uzorak. One imaju sposobnost potpuno obrstiti brijestova stabla. Brijestova osa listarica je prvi puta u Hrvatskoj nađena 2011. godine na nekoliko lokaliteta, ali ni na jednom nije došlo do značajnije defolijacije. Ova osa listarica može se smatrati invazivnom vrstom u Hrvatskoj, pa se očekuje njezino širenje u cijeloj Hrvatskoj, povećanje gustoće populacije i štete na brijestovim stablima.An invasive sawfly (Aproceros leucopoda; Hymenoptera, Argidae) has been attacking elms (Ulmus sp.) in Europe. It orginates from Japan and has been first recorded in Europe in 2003. In the paper the occurrence of A. leucopoda in Croatia is reported for the first time and prognosis of future dispersal and damages is given. Potential host plants of A. leucopoda are all native and introduced elm species in Europe. The sawfly has up to 4 generations per year and parthenogenetic reproduction, After six larval instars, eonymphs make loosely spun cocoons on the leaves (Figure 3 ). Adults (Figure 4) lay eggs along leaf margins. Young larvae (Figure 5) make distinctive zigzag feeding tracks on leaves (Figure 1 ), older larval instars devour the whole leaf and only midveins are left (Figure 2 ). The larve can completely defoliate elm trees which was the case in Japan, Hungary, Italy, Poland and Romania.
A. leucopoda was first recorded in Croatia in 2011 on several locations (Table 1, Figure 6). On the leaves a tipical zigzag feeding tracks were recorded, larvae and cocoons were found and adults were raised from the colected cocoons. The species was identified with the help od the key in Blank et al. (2010). The number of generations per year was not determined. The damage on the elm trees in Croatia was not severe, no defoliation was observed and only single leaves were completely consumed.
A. leucopoda can be considered as invasive species in Europe and Croatia, it can be expected that the sawfly will disperse to other parts of Croatia (to forests and urban trees) in the coming years. The sawfly will disperse actively (females are strong flyers) and passively (with traded material and vehicles). Complete defoliation of elm trees in Croatia can not be excluded in the coming years
