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Abstract. An invasive sawfly Aproceros leucopoda Takeuchi, 1939, which originates from East Asia, has colonized elms (Ulmus spp.) in Austria, Hungary, Poland, Romania, Slovakia and the Ukraine, at least since 2003. In Europe, the larvae can completely defoliate native and non-native elm trees and may cause at least partial dieback. Field observations indicate that elms are infested independent of their age and site characteristics. The life cycle of A. leucopoda is described based on material reared in Hokkaido, Japan. Parthenogenetic reproduction, short life cycle of summer generations and the ability to produce four generations per year result in the production of numerous progeny. The evolution of a seasonal dimorphism in head morphology, a simple cocoon that is attached directly to the host plant and a short period spent in the cocoon stage during summer, are putative apomorphies shared by Aproceros Takeuchi, 1939 and Aprosthema Konow, 1899. These traits reduce developmental costs and contribute to the proliferation of A. leucopoda. No specialized parasitoid, that can effectively reduce outbreaks of this species, is known. It is likely that this pest will spread into central and south-western Europe. Further monitoring of A. leucopoda is required to assess future range extensions in Europe, its exacerbating effect on Dutch elm disease and to find a suitable biocontrol agent. Concise keys to imaginal and larval stages are presented that will facilitate the identification of A. leucopoda.

Specialized trophic interactions in plant-herbivore-parasitoid food webs can spur "bottom-up" diversification if speciation in plants leads to host-shift driven divergence in insect herbivores, and if the effect then cascades up to the third trophic level.Conversely, parasitoids that search for victims on certain plant taxa may trigger "top-down" diversification by pushing herbivores into "enemy-free space" on novel hosts. We used phylogenetic regression methods to compare the relative importance of ecology versus phylogeny on associations between Heterarthrinae leafmining sawflies and their parasitoids. We found that: (1) the origin of leafmining led to escape from most parasitoids attacking external-feeding sawflies; (2) the current enemies mainly consist of generalists that are shared with other leafmining taxa, and of more specialized lineages that may have diversified by shifting among heterarthrines; and (3) parasitoid-leafminer associations are influenced more by the phylogeny of the miners' host plants than by relationships among miner species. Our results suggest that vertical diversifying forces have a significant-but not ubiquitous-role in speciation: many of the parasitoids have remained polyphagous despite niche diversification in the miners, and heterarthrine host shifts also seem to be strongly affected by host availability. K E Y W O R D S :Coevolution, enemy-free space, multitrophic networks, speciation, vertical diversification effects.

The 28 Eurasian species of Xyela Dalman, 1819 are revised based on material of ca 7,500 imagines including about 10 % reared specimens. Larvae of Eurasian Xyela usually are monophagous and feed inside the staminate cones of pines (Pinus spp., Pinaceae). Based on the reared material, on identification by barcoding and on additional collection observations, the larval host associations for the Xyela species are summarized and additional biological observations are noted. An illustrated key to the species and distribution maps are presented. Eight species are described as new: X. altenhoferi Blank, sp. nov. (Croatia), X. heldreichii Blank, sp. nov. (Albania, Greece), X. koraiensis Blank & Shinohara, sp. nov. (Russia, South Korea), X. peuce Blank, sp. nov. (Bulgaria), X. pumilae Blank & Shinohara, sp. nov. (Japan), X. rasnitsyni Blank & Shinohara, sp. nov. (China, Russia, South Korea), X. sibiricae Blank, sp. nov. (Mongolia, Russia), and X. uncinatae Blank, sp. nov. (Andorra, France, Spain, Switzerland). For the other species redescriptions are given. A lectotype is designated for X. longula Dalman, 1819, and neotypes are designated for X. graeca J.P.E.F. Stein, 1876 and Pinicola julii Brébisson, 1818. The following new synonymies are proposed: X. lii Xiao, 1988, syn. nov. of X. sinicola Maa, 1947; X. nigroabscondita Haris & Gyurkovics, 2011, syn. nov. of X. lugdunensis (Berland, 1943); and X. suwonae Ryu & Lee, 1992, syn. nov. of X. ussuriensis Rasnitsyn, 1965.

Systematics and ecology of the larval parasites (Hym., Ichneumonidae, Braconidae, Eulophidae) of leafmining sawflies (Hym., Tenthred.) Between 1975 and 1978 the parasite‐complex of larvae of leafmining sawflies was studied in Austria and Switzerland. The species reared belong to the Ichneumonidae (Tryphoninae, Scolobatinae, Porizontinae, Ephialtinae) Braconidae and Eulophidae. The species of the Tryphoninae, Scolobatinae and Porizontinae are strictly host‐specific, whereas species of the Ephialtinae, Braconidae and Eulophidae are polyphagous. Tables show parasite species and their host species. Additional parts study oviposition, development and synchronisation with the host species. Some species of the Tryphoninae cannot be distinguished in the adult stage; illustrations are included to determine these species by their eggform. Zusammenfassung In den Jahren 1975 bis 1978 wurde versucht, den Komplex der Larvenparasiten minierender Blattwespen (Fenusini, Heterarthrini) hauptsächlich in Österreich, teils auch in der Schweiz zu erfassen. Es wurden Arten der Ichneumonidae (Tryphoninae, Scolobatinae, Porizontinae und Ephialtinae), der Braconidae und der Eulophidae gezogen. Arten der Tryphoninae, Scolobatinae und Porizontinae sind streng monophag. Es werden Listen über die Parasitenarten und ihre Wirte angeführt. Dazu kommen Angaben über das Eiablageverhalten, die Entwicklung und Synchronisation mit den Wirtsarten. Anhand von Abbildungen von Eiern und deren Ankerstrukturen von Arten der Tryphoninae wird aufgezeigt, daß eine Artentrennung möglich ist, die bisher anhand der Imagines versagt. Diese Artentrennung wird auch durch biologische Unterschiede wie Wirtsspezifität und Eiablageverhalten gestützt.