Ergänzende Informationen zu Publikationen von Florine Leuthardt

The box-tree moth Cydalima perspectalis (Walker) is an invasive pest causing severe damage to box trees (Buxus spp.). It is native to Japan, Korea and China, but established populations have been recorded in a number of locations across Europe since 2007 and the spread of the insect continues. The developmental investigations suggest that larvae overwinter mainly in their 3rd instar in Europe and that diapause is induced by a day length of about 13.5h. One and a half to 2months in the cold are necessary to terminate diapause. Threshold temperatures for development and number of degree-days to complete a generation are slightly different from those calculated in previous studies in Japan. A bioclimatic (CLIMEX (R)) model for C.perspectalis in Europe was developed, based on climate, ecological and developmental parameters from the literature and new field and laboratory studies on diapause termination, thermal requirements and phenology. The model was then validated with actual distribution records and phenology data. The current distribution and life history of C.perspectalis in Europe were consistent with the predicted distribution. The climate model suggests that C.perspectalis is likely to continue its spread across Europe, except for Northern Fenno-Scandinavia, Northern Scotland and high mountain regions. The northern distribution of C.perspectalis is expected to be limited by a number of degree-days above the temperature threshold insufficient to complete a generation, whereas its southern range is limited by the absence of a cold period necessary to resume diapause. The model predicts relatively high Ecoclimatic Indices throughout most of Europe, suggesting that the insect has the potential of becoming a pest in most of its predicted range. However, damage is likely to be higher in Southern and Central Europe where the moth is able to complete at least two generations per year.

Keywords: bioclimatic model - CLIMEX - Cydalima perspectalis - diapause - invasive species - temperature requirements

Larvae of the moth Cydalima perspectalis are specialized on box trees (Buxus spp.). Native to eastern Asia, the moth has been introduced to Europe in 2007 and is nowadays causing severe damage to box trees in private and public gardens, as well as in semi-natural box tree forests. Box trees contain highly toxic triterpenoid alkaloids which may be sequestered by specialized herbivores such as C. perspectalis. We determined the alkaloid composition in leaves of the five most common box tree varieties in Europe belonging to two Buxus species using liquid chromatography–mass spectrometry (LC–MS) metabolite profiling. We also examined whether larvae and moths of C. perspectalis accumulate alkaloids from the different box tree varieties. The differences in alkaloid composition observed between the box tree species Buxus sempervirens and Buxus microphylla were mirrored in the tissue of C. perspectalis larvae fed on either of the different box tree species, indicating uptake of alkaloids. The larvae stored large amounts of dibasic alkaloids in their body, while monobasic alkaloids were metabolized and/or excreted. Newly emerged adult moths contained no traces of alkaloids.

Keywords: Buxus - Lepidoptera - chemical defence - triterpenoid alkaloids - plant–insect interactions - UHPLC–QTOFMS

The spread of D. perspectalis has been examined in the region of Basel over a period of six months. First results suggest the occurrence of three generations per year. Due to its rapid spread, D. perspectalis might colonize all suitable habitats in Switzerland within a few years.

Keywords: Diaphania perspectalis - Pyralidae - Buxus - Basel