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Groß-Gerungs, Austria

Leppanen S.A.,University of Eastern Finland | Altenhofer E.,Etzen 39 | Liston A.D.,Senckenberg Institute | Nyman T.,University of Eastern Finland | Nyman T.,University of Zurich
Evolution | Year: 2013

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. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution. Source

Blank S.M.,Senckenberg Institute | Shinohara A.,National Museum of Nature and Science | Altenhofer E.,Etzen 39
Zootaxa | Year: 2013

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. Copyright © 2013 Magnolia Press. Source

Blank S.M.,Senckenberg Institute | Hara H.,Forestry Research Institute | Mikulas J.,Corvinus University of Budapest | Csoka G.,Forest Research Institute | And 7 more authors.
European Journal of Entomology | Year: 2010

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. © 2003 Institute of Entomology. Source

Leppanen S.A.,University of Eastern Finland | Altenhofer E.,Etzen 39 | Liston A.D.,Senckenberg Institute | Nyman T.,University of Eastern Finland | Nyman T.,University of Zurich
Molecular Phylogenetics and Evolution | Year: 2012

The habit of mining within leaves has evolved convergently in numerous plant-feeding insect taxa. Many leaf-mining groups contain a large number of species with distinct feeding preferences, which makes them highly suitable for studies on the evolutionary history of host-plant use and on the role of niche shifts in speciation. We aimed to clarify the origin, classification, and ecological evolution of the tenthredinid sawfly subfamily Heterarthrinae, which contains c. 150 leaf-mining species that collectively feed on over 20 plant genera around the world. For this, we reconstructed the phylogeny of representative heterarthrine species and diverse outgroups from the superfamily Tenthredinoidea on the basis of DNA sequence data collected from two mitochondrial (CoI and Cytb) and two nuclear (EF-1α and NaK) genes. Thereafter, we inferred the history of niche diversification within Heterarthrinae by plotting larval host-plant associations on the trees, and by contrasting a time-calibrated leaf-miner phylogeny with the phylogeny of their host plants. The results show that: (1) heterarthrine leaf-miners constitute a monophyletic group that arose from external-feeding blennocampine lineages within the Tenthredinidae c. 110-80 million years ago; (2) heterarthrines generally radiated well after their host taxa, and extant host-plant associations therefore result from a combination of host conservatism and occasional shifts among available plant taxa; and (3) diversification in Heterarthrinae apparently occurs by multiple mechanisms, including sympatric or allopatric ecological speciation, non-ecological allopatric speciation, and possibly allochronic speciation. Overall, both present and historical host-use patterns within the Heterarthrinae exhibit striking similarities to patterns found in co-occurring herbivore taxa. © 2012 Elsevier Inc. Source

Smith D.R.,U.S. Department of Agriculture | Altenhofer E.,Etzen 39
Proceedings of the Entomological Society of Washington | Year: 2011

Fenusa absens, n. sp., is described from Novosibirsk, Russia. It was reared from leaf mines in Siberian elm, Ulmus pumila L. Placement of this species in Fenusa Leach is discussed, and comparison is made to other species of elm leafmining sawflies. Because Ulmus pumila is not native to the Novosibirsk region, it is possible that Fenusa absens is an introduced species in the area. Source

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