Ján Kulfan

The harlequin ladybird, Harmonia axyridis: global perspectives on invasion history and ecology

The harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is native to Asia but has been intentionally introduced to many countries as a biological control agent of pest insects. In numerous countries, however, it has been introduced unintentionally. The dramatic spread of H. axyridis within many countries has been met with considerable trepidation. It is a generalist top predator, able to thrive in many habitats and across wide climatic conditions. It poses a threat to biodiversity, particularly aphidophagous insects, through competition and predation, and in many countries adverse effects have been reported on other species, particularly coccinellids. However, the patterns are not consistent around the world and seem to be affected by many factors including landscape and climate. Research on H. axyridis has provided detailed insights into invasion biology from broad patterns and processes to approaches in surveillance and monitoring. An impressive number of studies on this alien species have provided mechanistic evidence alongside models explaining large-scale patterns and processes. The involvement of citizens in monitoring this species in a number of countries around the world is inspiring and has provided data on scales that would be otherwise unachievable. Harmonia axyridis has successfully been used as a model invasive alien species and has been the inspiration for global collaborations at various scales. There is considerable scope to expand the research and associated collaborations, particularly to increase the breadth of parallel studies conducted in the native and invaded regions. Indeed a qualitative comparison of biological traits across the native and invaded range suggests that there are differences which ultimately could influence the population dynamics of this invader. Here we provide an overview of the invasion history and ecology of H. axyridis globally with consideration of future research perspectives. We reflect broadly on the contributions of such research to our understanding of invasion biology while also informing policy and people.

Litter-dwelling beetles in primeval forests of Central Europe: Does deadwood matter?

We investigated the distribution pattern of litter dwelling beetles in four primeval forests of the Western Carpathians. The forests are situated in two mountain ranges and are either southerly exposed oak forests or northerly exposed beech forests. Beetles were extracted from leaf litter of plots close to coarse woody debris (c-CWD) and distant from coarse woody debris (d-CWD). We collected 2946 individuals of 172 species. Plots close to CWD usually were hot spots of species richness and beetle density, which could be increased two-fold and five-fold, respectively, when compared to d-CWD sites. The influence of CWD within each forest type was stronger than that of any other environmental factor. The c-CWD plots were characterised by both a higher presence of common species and a higher number of rare species. Especially, zoophagous and mycetophagous beetles were enhanced. The assemblage wide carrying capacity at c-CWD sites varied in respect to the gradients of temperature and moisture within a forest. A longer gradient provided a higher carrying capacity. We assume that the influence of downed deadwood on litter dwelling beetles will also be effective in commercial forests and stop the downward spiral with continuing loss of species.

The distribution pattern of centipedes in four primeval forests of central Slovakia

We investigated the distribution pattern of centipedes (Chilopoda) in four primeval forests of the western Carpathians, central Slovakia. The forests are located in two different mountain ranges (Kremnické vrchy and Pol’ana Mountains), which are exposed on either the southern (Boky, Rohy) or northern slopes (Pol’ana, Badín). In these forests, the influence of coarse woody debris (CWD) on centipede distribution was studied, by distinguishing sampling sites on the forest floor, close to CWD (c-CWD) and distant from CWD (d-CWD). In total, we collected 2,706 individuals from 20 species of centipedes. Average species richness and number of individuals per forest ranged from 8 to 12 species/m2 and from 244 to 486 individuals/m2. The oak forests on south facing slopes harboured several species, which did not occur in the more northern exposed fir-beech forests. Number of species as well as individuals, however, varied more within than between individual forests. Increase of species number and density was mainly caused by CWD and was more pronounced on the southern slopes (P<0.001), characterized by high temperatures and low precipitation, than on the northern slopes (n.s. to P<0.01), characterized by low temperatures and high precipitation. It was found that CWD did not generally increase (species) diversity.

Suppression of Soil Microorganisms by Emissions of a Magnesite Plant in the Slovak Republic

In April 1996, we collected soil samples in thevicinity of a magnesite plant at Lubeník, southernSlovakia, and screened them for soil microbial biomassand activity. Six investigated sites were chosen alonga transect, with distances ranging from 600 to 8000 mfrom the plant, to represent a gradient ofintoxication. Soil microbial cellulase activity,respiration, biomass, metabolic quotient of the soilmicrobiota, and numbers of platable fungi increasedwith increasing distance from the plant, i.e.decreasing degree of intoxication. The observedgradients of soil microbial characteristics of theinvestigated sites reflect the physico-chemical soilparameters and the floristic characteristics of thesesites, and may be used to predict transitory changesduring amelioration.

The invasion history, distribution and colour pattern forms of the harlequin ladybird beetle Harmonia axyridis (Pall.) (Coleoptera, Coccinellidae) in Slovakia, Central Europe

Abstract The harlequin ladybird beetle Harmonia axyridis (Coleoptera, Coccinellidae) has invaded and established in Slovakia. Following unintentional introduction in 2008, the spread of the alien coccinellid was very fast. By the end of 2009, it was recorded across the whole country, and by the end of 2012 it was widely distributed and common in various habitats, particularly gardens, orchards and urban areas, where it was most frequent on trees. The rate of eastward spread was approximately 200 km year-1, similar to the overall rate of spread in Europe. Between 2008 and 2012, the coccinellid was recorded in a total of 153 localities, in altitudes ranging from 98 to 1,250 m. Most records of this species were made in lowlands, hilly areas and valleys separating mountain ridges. However, it was only rarely documented in areas above 700 m a.s.l. The non-melanic colour form (f. succinea) was dominant along a longitudinal transect including eight urban areas across Slovakia, with the frequency of melanic forms (f. spectabilis and f. conspicua together) between 6.3 and 19.2% and a median equal to 10.5%. The invasion history and distribution of H. axyridis in Slovakia are discussed with regard to the time sequence of records, rate of spread, altitudinal distribution, anthropogenic dispersal, effective recording, proportion of melanic forms and other relevant aspects associated with the spread of this successful invader.

Assemblage structure and altitudinal distribution of lady beetles (Coleoptera, Coccinellidae) in the mountain spruce forests of Pol’ana Mountains, the West Carpathians

In two successive years we recorded a total of 3,636 individuals and 17 species of adult lady beetles (Coleoptera, Coccinellidae) in the spruce forests of Pol’ana Mts (the West Carpathians) at altitudes ranging from 600 m to 1,300 m a.s.l. Four lady beetle species were documented as predominating (dominance of abundance > 5%) over the study period. They were the following: Aphidecta obliterata (1,828 individuals and 50.3%), Coccinella septempunctata (634 individuals and 17.4%), Adalia conglomerata (594 individuals and 16.3%) and Anatis ocellata (279 individuals and 7.7%). The assemblages of lady beetles differed among the areas and also between the years. The season revealed neglegible effect on distribution of lady beetles, whereas the effect of altitude was more pronounced. A. conglomerata preferred the areas at lower altitude (600–725 m) to those at middle (900–925 m) and/or upper altitude (1,250–1,300 m). In contrast, A. obliterata and C. septempuctata were most abundant in the area at middle altitude. The altitudinal location of area partly explained the variability in abundance of lady beetles. The first ordination axis constructed by means of correspondence analysis (CA) represented an altitudinal gradient and accounted for 19.4% of the total variance of the species data. The great proportion of lady beetle species not typically associated with spruce and/or other coniferous trees than spruce (70.6%, n = 17) may be explained by an ecotonal effect.

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.

Mites Trichouropoda and Uroobovella spp. (Uropodoidea) phoretic on bark beetles (Scolytinae): a comparison from a declining mountain spruce forest in Central Europe

ABSTRACT Mites of the genera Trichouropoda and Uroobovella are characteristic associates of bark beetles which act as agents of their dispersal in many types of forest ecosystems worldwide. We compared the phoretic assemblages of Trichouropoda and Uroobovella mites on six species of bark beetle associated with Norway spruce (Picea abies (L.) Karsten), namely: Dryocoetes autographus Ratzeburg, Hylastes cunicularius Erichson, Hylurgops palliatus (Gyllenhal), Ips typographus (Linnaeus), Pityogenes chalcographus (Linnaeus) and Polygraphus poligraphus (Linnaeus). Bark beetles were caught at random in non-baited flight-interception traps set in the shrub layer of a declining mountain spruce forest in the Tatra Mountains, West Carpathians, Central Europe. Over four years of a bark beetle outbreak, a total of six species of mites and 12 phoretic associations between mites and beetles were recorded. A newly documented host association includes that of Trichouropoda pecinai Hirschmann & Wiśniewski with H. palliatus. The most frequently recorded mite-beetle associations were: T. pecinai with H. cunicularius, Trichouropoda obscura (Koch) with H. palliatus, Trichouropoda polytricha (Vitzthum) with P. chalcographus and I. typographus and Uroobovella vinicolora (Vitzthum) with D. autographus. The results suggest that most of the recorded mite species have distinct bark beetle dispersants and that niche partitioning in these dispersants may be reflected by the observed mite–host associations.

ATTRACTTION OF BARK BEETLES (COLEOPTERA: SCOLYTIDAE) TO NORWAY SPRUCE IN TIMBERLINE FOREST IN TATRA MOUNTAINS, WEST CARPATHIANS

Attracttion of bark beetles (Coleoptera: Scolytidae) to Norway spruce in timberline forest in Tatra Mountains, West Carpathians Attraction of bark beetles (Coleoptera: Scolytidae) to Norway spruce was studied in the timberline forest in Tatra Mountains, West Carpathians, Central Europe, by trapping bark beetles in flight interception traps fixed to the lower parts of the 18 trunks of spruce trees, and by recording colonizations of bark beetles on those trees in 2004. The trees were devoid of needles in the upper crown (1/4 up to 1/3 of the tree top dead) and were growing in three distant sample plots. Each plot was representing three different situations (biotopes) in the timberline spruce forest - forest, forest line and tree line, in altitudes between 1,280-1,560 m. A total of 18 traps yielded a total of 5,015 individuals and 19 bark beetle species associated with spruce, the five of which, Phtorophloeus spinulosus, Xyloterus lineatus, Pityophthorus pityographus, Pityogenes chalcographus, Ips typographus, were also documented to be developing in the the studied trees. Traps in the forest line yielded more individuals of bark beetles (all species considered together) than those in the forest and the tree line, although this was not significant (P>0.05, K-W Anova). The bark beetle assemblages showed very low dissimilarity in their structure between the forest and forest line, however, the assemblages in these two situations, aparently, differed from the assemblage in the tree line. Over the period 2004 - 2008 three (16.7%) of the 18 studied trees died. All documented cases of the tree mortality were associated with colonization by I. typographus. Atraktivita smreka pre podkôrnikovité chrobáky (Coleoptera: Scolytidae) na hornej hranici lesa v Tatrách, Západné Karpaty Príspevok sumarizuje výsledky výskumu atraktivity 18 chradnúcich dospelých jedincov smreka (Picea abies) pre podkôrnikovité chrobáky (Coleoptera: Scolytidae) v oblasti hornej hranice lesa v Tatrách v roku 2004 a zároveň hodnotí prežívanie týchto smrekov v rokoch 2004-2008. Do chemicky nevnadených nárazových lapačov umiestnených na kmeňoch predmetných smrekov bolo odchytených spolu 5 015 jedincov a 19 druhov podkôrnikovitých vývinom viazaných na smrek. Najviac jedincov podkôrnikovitých (všetky druhy hodnotené spolu) bolo získaných z lapačov na smrekoch rastúcich na hranici, resp. v okraji súvislého smrekového lesa, menej z lapačov v smrekovom lese pod touto hranicou a najmenej z lapačov v oblasti jednotlivého výskytu smreka v pásme vysokohorských lúk a kosodreviny. Dva sledované jedince smreka odumreli v roku 2004, jeden jedinec odumrel v roku 2007. Všetky tri prípady odumretia smreka (16,7 %, n = 18) súviseli s úspešnou kolonizáciou smrekov lykožrútom smrekovým.

Phytophagous larvae occurring in Central and Southeastern European oak forests as a potential host of Entomophaga maimaiga (Entomophthorales: Entomophthoraceae) – A field study

We evaluated the presence and impact of Entomophaga maimaiga on both target and non-target phytophagous larvae. All six study plots, with low gypsy moth population density, were situated in Central and Southeastern European oak forests and E. maimaiga had previously been reported from these plots. Totally, 45 of 4,045 (1.13%) collected non-target larvae died due to fungal infections. No non-target insect specimen was infected by E.maimaiga, although the presence of the pathogen could not be fully excluded in three cadavers. Out of 1,780L.dispar larvae collected, 15individuals (0.84%) were infected by E.maimaiga.