DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 7-8/2012 str. 54     <-- 54 -->        PDF

In total, 28 taxa of parasitoids from the superfamily Chalcidoidea and 4 taxa from the superfamily of Ichneumonoidea have been found (Table 1). Table 1 shows domination index (D) for parasitoid species found for a host leaf miner. This research compares the parasitoid assemblages of different species of leafminers, the results have been obtained after mass rearings of parasitoids from different localities and different collection times and it does not give detailed insight into parasitism percentages and the seasonal distribution of parasitoid species within a parasitoid assemblage. Table 2 shows values of Shannon’s diversity index H and evenness of species E, and Figure 1 shows dendrogram from cluster analyses grouping leaf miner species according to the similarities of their parasitoid assemblages.
The majority of parasitoid species found are generalist species found on other species of leaf miners from the order Lepidoptera. P. roboris/P. quercifoliella have the most diverse parasitoid assemblage (the highest H value) (Table 2) followed by T. ekebladella. Oaks support rich fauna of taxonomicaly and ecologicaly similar leaf miner species and free exchange of parasitoids is enabled among them. All the parasitoid species found on these leafminers are generalist. They also have the highest E value (Table 2) because they lack specific monophagous parasitoid species. P. klemannella has lower diversity indices H and E because of the dominance of specific parasitoids from Encyrtidae family. P. platani has two dominant parasitoid species Minotetrastichus platanellus and Pediobius saulius. Dendrogram shows that P. roboris/P. quercifoliella, P. robiniella, P. leucographella, Pa. robiniella i T. ekebladella have similar parasitoid assemblages. Very similar are T. ekebladella and Pa. robiniella, both host species grow on the same sites together (oak and black locust) and generalists can search for similar mines: white upper surface leaf mines. The greater linkage distance between P. klemannella i P. platani can be explained with the dominance of specific monophagous parasitoid species in the assemblage. The similarities between parasitoid assemblages of native (P. roboris/P. quercifoliella, T. ekebladella) and alien (P. leucographella, P. robiniella, Pa. robiniella, C. ohridella) leaf miner species show that the native generalist parasitoids have adapted to new hosts. Ten species of parasitoids have been found on C. ohridella, with Pediobius saulius and Minotetrastichus frontalis as two dominant species (Table 1). This research has shown that invasive leaf miner species in Croatia have recruited a parasitoid community similar to the native leaf miner species and that this process has occurred quite rapidly.
Key words: Tischeria ekebladella, Parectopa robinella, Cameraria ohridella, Phyllonorycter sp., diversity indices, polyphagous parasitoids, adaptation, new host