Larval feeding of Cydalima perspectalis on box trees with a focus on the spatial and temporal distribution

The box tree moth Cydalima perspectalis is an invasive pest on box trees originating from Eastern Asia which spread throughout Europe. We assessed the efficacy of photo-eclectors (emergence boxes) for the detection of its larvae. We also investigated their spatial distribution on the hosts and the spatial and temporal distribution of the leaf damage caused by this pest in Slovakia. Our results showed non-uniform vertical distribution of the overwintering larvae and leaf damage on the trees. The larval abundance in the spring was significantly affected by the height of the branches above the ground. During spring, the larvae occurred most abundantly in the upper parts of the trees. The leaf damage was greatest in the lower parts throughout the growing season. During the progress of the infestation, the development of the damage in the lower and middle parts was similar. In the upper part, the initial increase in the damage was slow, but accelerated four months before the complete defoliation. The field estimation of the proportion of damaged leaves and the accurate assessment based on counting the damaged leaves suggest a consis­tency between these estimates. Hence, a quick field estimation of the leaf damage may be utilised by horticultural practices

Effects of a host tree on movement and distribution of winter geometrid moths (Lepidoptera): thickness of trunks and branches

Adult moths from an ecological group of winter geometrid species look for trees where they copulate and females lay eggs. We investigated how tree trunk and lower branch thickness affects the occurrence of females on trunks and branches and how the density of females and tree trunk thickness affects the occurrence of males on trunks. The research was carried out in a xeric thermophilous oak forest in southern Slovakia (Central Europe) in the winter season 2014–2015. The moths were obtained from Quercus pubescens trees by sticky bands. Three autumn species Operophtera brumata, Erannis defoliaria, Alsophila aceraria and four spring species Agriopis leucophaearia, Agriopis marginaria, Apocheima hispidaria, Phigalia pilosaria were recorded. We have found out that females had not exclusively negative geotactic behaviour as they (except for the rare P. pilosaria) occurred also on lower branches. Tree trunk and lower branch thickness had a positive effect on abundance of females of the three most abundant species (A. leucophaearia, O. brumata, E. defoliaria) on trunks and lower branches. Tree trunk thickness had a positive effect on density of the females of A. leucophaearia on trunks but not on O. brumata and E. defoliaria. The abundance of the males of O. brumata, E. defoliaria and A. leucophaearia on trunks was positively affected by tree trunk thickness and the density of their females

Species assemblages of ladybirds including the harlequin ladybird Harmonia axyridis: a comparison at large spatial scale in urban habitats

We evaluated the status of native ladybird assemblages in the presence of the non-native ladybird Harmonia axyridis Pallas (Coleoptera: Coccinellidae) in three European countries. To achieve this, we assessed the abundance of ladybirds from common host plants in urban areas of Great Britain, Czech Republic and Slovak Republic in 2014. We determined (i) the effects of season, host plant, location, abundance of H. axyridis and aphids on the ladybird species assemblage, (ii) the relationship between ladybird abundance and aphid density, (iii) the relationship between diversity of native ladybird species and the abundance of H. axyridis. There was a non-linear relationship between abundance of ladybirds and abundance of aphids but we found the abundance of other ladybird species was not correlated with H. axyridis. We highlight the value of large-spatial scale studies for revealing patterns in community assemblages and ultimately informing understanding of ecosystem resilience