Zusammenfassende Betrachtung über die Verbreitung und die Biologie von Cameraria ohridella Deschka & Dimic (Lep., Gracillariidae) in Griechenland

Anfang der 80er Jahre wurde zum ersten Mal von SIMOVA-TOSIC & FILEV (1985) in der Nähe des Ohrid Sees (Balkan) eine unbekannte Miniermotte bei einem Massenauftretten an Aesculus hippocastanum L. festgestellt. Die neue Art wurde von DESCHKA & DIMIC (1986) Cameraria ohridella genannt. Seit dieser Erstentdeckung der Motte am Balkan lässt sich eine rasche Ausbreitung des Schädlings in Europa beobachten. Aufgrund der inzwischen erfolgten zahlreichen Veröffentlichungen ist davon auszugehen, dass bis jetzt nahezu ganz Europa, ausgenommen Skandinavien, von der Motte besiedelt wurde. In Griechenland wurde die Motte 1996 von SKUHRAVY (1999) bei Florina (Nord Griechenland) erstmals festgestellt. Ziel der vorliegenden Arbeit war, Erkenntnisse über die Biologie der Motte in Griechenland zu gewinnen. Die durchgeführten Untersuchungen beziehen sich auf die Jahre 2001 bis 2004 und wurden im Rahmen des E.U. Programms CONTROCAM durchgeführt.The horse-chestnut leaf miner, Cameraria ohridella (Lep., Gracillariidae) is a relative new pest in Europe and especially in Greece, where it was found for the first time in 1996. In the framework of the EU Program CONTROCAM, in which the Department of Forestry in Drama (Technological Educational Institute of Kavala) participates together with 7 other European partners, the study on this insect started in Greece in 2001. Until now, on-site observations showed that the insect attacks only horse chestnut trees (both wild and ornamental) in different locations in Greece. The moth has not been found on Acer monspessulanum, A. obtusatum, A. hyrcanum, A. platanoides, A. heldreichii, A. pseudoplatanus, A. tataricum, A. creticum, A. campestre (in the forests) and A. negundo (in the parks) in any occasion. From the results of live-trapping by pheromone traps at three different locations in Greece and from phenological observations, we found that this insect usually has three generations per year in Greece. Only under very favourable conditions it may develop a fourth one, like in Ioannina in the year 2003. Another very important feature refers to the differences between the moth population densities from year to year and tree to tree at the same location. These differences require further analysis in terms of the climatic conditions (first case), as well as of the quality of food (second case)

Temporal and spatial variations in the parasitoid complex of the horse chestnut leafminer during its invasion of Europe

The enemy release hypothesis posits that the initial success of invasive species depends on the scarcity and poor adaptation of native natural enemies such as predators and parasitoids. As for parasitoids, invading hosts are first attacked at low rates by a species-poor complex of mainly generalist species. Over the years, however, parasitoid richness may increase either because the invading host continuously encounters new parasitoid species during its spread (geographic spread-hypothesis) or because local parasitoids need different periods of time to adapt to the novel host (adjustment-hypothesis). Both scenarios should result in a continuous increase of parasitoid richness over time. In this study, we reconstructed the development of the hymenopteran parasitoid complex of the invasive leafminer Cameraria ohridella (Lepidoptera, Gracillariidae). Our results show that the overall parasitism rate increases as a function of host residence time as well as geographic and climatic factors, altogether reflecting the historic spread of C. ohridella. The same variables also explain the individual parasitism rates of several species in the parasitoid complex, but fail to explain the abundance of others. Evidence supporting the “geographic spread-hypothesis” was found in the parasitism pattern of Cirrospilus talitzkii (Hymenoptera, Eulophidae), while that of Pediobius saulius, another eulophid, indicated an increase of parasitism rates by behavioral, phenological or biological adjustments. Compared to fully integrated host-parasitoid associations, however, parasitism rates of C. ohridella are still very low. In addition, the parasitoid complex lacks specialists, provided that the species determined are valid and not complexes of cryptic (and presumably more specialized) species. Probably, the adjustment of specialist parasitoids requires more than a few decades, particularly to invaders which establish in ecological niches free of native hosts, thus eliminating any possibility of recruitment of pre-adapted parasitoids

Tracking origins of invasive herbivores through herbaria and archival DNA: the case of the horse-chestnut leaf miner

International audienceDetermining the native geographic range or origin of alien invasive species is crucial to developing invasive species management strategies. However, the necessary historical dimension is often lacking. The origin of the highly invasive horse-chestnut leaf-mining moth Cameraria ohridella has been controversial since the insect was first described in 1986 in Europe. Here, we reveal that herbarium collections across Europe indicate a Balkan origin for C ohridella. We successfully amplified nuclear DNA and mitochondrial DNA barcode fragments from larvae pressed within leaves of herbarium samples collected as early as 1879. These archival sequences confirm an identity of C ohridella and set back its history in Europe by more than a century. The herbarium samples uncovered previously unknown mitochondrial haplotypes and locally undocumented alleles, showing local outbreaks of C ohridella back to at least 1961 and dynamic frequency changes that may be associated with road development. This case history demonstrates that herbaria are greatly underutilized in studies of insect–plant interactions, herbivore biodiversity, and invasive species' origins

Tracking origins of invasive leaf-mining moths using herbaria and minibarcodes

International audienc

Tracking origins of invasive leaf-mining moths using herbaria and minibarcodes

International audienc

Tracking origins of the highly invasive horse-chestnut leafminer using herbaria and minibarcodes

International audienc

Tracking origins of the highly invasive horse-chestnut leafminer using herbaria and minibarcodes

International audienc

Tracking origins of the highly invasive horse-chestnut leafminer using herbaria and minibarcodes

International audienc