Urbanization leads to an increase in built-up areas but also creates landscape element mosaics, providing various habitats for phytophagous species. Sap-feeding insects (Hemiptera) form a major component of arboreal insect communities with many highly damaging and difficult-to-control pests of urban trees. Outbreaks of their populations are often reported from city centers. Here, we studied how urbanization (defined as the proportion of impervious surfaces within a 200 and 500-m radius) affected canopy-dwelling phytophagous hemipterans (true bugs, true hoppers, and psyllids) on field maple (Acer campestre) trees. We also considered the amount of green urban areas (gardens and parks) in the surrounding landscape and the characteristics of the hemipteran species (origin, diet, and body size). We found that sap-feeding hemipterans did not show consistent responses to urbanization. The occurrence of only one species (Alebra wahlbergi) increased while the abundance of other native species (e.g., Acericerus ribauti, Palomena prasina, and Rhinocola aceris) decreased with increasing level of urbanization. At the same time, the serious pest of urban trees, Metcalfa pruinosa, but also two major crop pests, Nezara viridula and Halyomorpha halys had the highest numbers at an intermediate level of urbanization with a relatively high proportion of gardens and parks in the landscape. We also found less native and more generalist hemipterans in highly urbanized sites compared to less densely built areas. Our results suggest that, apart from their substantial contribution to ecosystem services, green urban areas can favor some major insect pests of urban trees and agricultural crops.

The native green apple aphid (Aphis pomi DeGeer) and the invasive green spirea aphid (Aphis spiraecola Patch) share apple as a common host plant during the summer months in Central Europe. Various studies suggest that, under certain conditions, the originally host-alternating A. spiraecola is able to overwinter on apple as a winter host, following a similar life history to A. pomi. In this study, we collected stem mothers (fundatrices) and aphids of the second generation (fundatrigeniae) from ten localities throughout Hungary for nine consecutive springs to assess whether A. spiraecola can overwinter on apple as a winter host. All the collected aphid individuals (1126 aphids from 114 stem colonies during the nine years of the study) belonged to A. pomi, indicating that A. spiraecola does not, or very rarely can, overwinter on apple under Central European conditions.

Selection forces often generate sex-specific differences in various traits closely related to fitness. While in adult spiders (Araneae), sexes often differ in coloration, body size, antipredator, or foraging behavior, such sex-related differences are less pronounced among immatures. However, sex-specific life-history strategies may also be adaptive for immatures. Thus, we hypothesized that among spiders, immature individuals show different life-history strategies that are expressed as sex-specific differences in body parameters and behavioral features, and also in their relationships. We used immature individuals of a protandrous jumping spider, Carrhotus xanthogramma, and examined sex-related differences. The results showed that males have higher mass and larger prosoma than females. Males were more active and more risk tolerant than females. Male activity increased with time, and larger males tended to capture the prey faster than small ones, while females showed no such patterns. However, females reacted to the threatening abiotic stimuli more with the increasing number of test sessions. In both males and females, individuals with better body conditions tended to be more risk averse. Spiders showed no sex-specific differences in interindividual behavioral consistency and in intraindividual behavioral variation in the measured behavioral traits. Finally, we also found evidence for behavioral syndromes (i.e., correlation between different behaviors), where in males, only the activity correlated with the risk-taking behavior, but in females, all the measured behavioral traits were involved. The present study demonstrates that C. xanthogramma sexes follow different life-history strategies even before attaining maturity.

By mitigating the negative effects of urbanization, urban trees contribute significantly to the well-being of urban citizens. However, trees themselves are also exposed to urban stress that can influence tree condition and tree-herbivore interactions. Maple species (Acer spp.) are among the most commonly planted trees in urban areas throughout North America and Europe. Among these species, field, sycamore, and Norway maple are native to Europe, but tolerate environmental stress to varying degrees. Here, we compared the phytophagous insect communities in the canopy of these tree species in the city of Budapest, Hungary. We also examined the stress level [expressed as peroxidase (POD) enzyme activity], and physiological condition (expressed as degree of leaf necrosis and leaf fall) of the maple trees, and their relationship to herbivore abundance. We observed higher total abundance of phytophagous insects on field and sycamore maple compared to Norway maple. Most herbivorous species were associated with field maple, sycamore had the highest aphid densities, and Norway maple harbored the least specific phytophagous insect community. Field maple trees were in the best condition while Norway maple trees in the worst condition, i.e., with the highest proportion of necrotic leaf surface area. The super-abundant planthopper species, Metcalfa pruinosa positively affected the POD activity of trees, but did not influence their condition. On the contrary, M. pruinosa abundance was driven by tree condition, with higher numbers on healthier trees. Our findings suggest that the abundance of phytophagous insects in the canopy of maple trees is highly determined by tree condition, and in this study field maple had the highest and Norway maple the lowest tolerance for urban stress.

Apricot aphid, Myzus mumecola (Matsumura) (Homoptera: Aphididae), was recorded as a new pest of apricot in Hungary in the spring of 2020. Identification was based on morphological and genetical (mitochondrial COI region) characteristics. M. mumecola most likely arrived in Hungary in the last 2–3 years and has quickly become a widespread pest causing significant damage to young apricot trees. Colony development, damage and differences in susceptibility between cultivars are described. The presence of Plum pox virus in M. mumecola samples was detected, and all isolates belonged to the PPV-D subgroup. Illustrations of the most important diagnostic characters of M. mumecola are provided.

Spiders (Araneae) form abundant and diverse assemblages in agroecosystems such as fruit orchards, and thus might have an important role as natural enemies of orchard pests. Although spiders are polyphagous and opportunistic predators in general, limited information exists on their natural prey at both species and community levels. Thus, the aim of this study was to assess the natural prey (realized trophic niche) of arboreal hunting spiders, their role in trophic webs and their biological control potential with direct observation of predation events in apple orchards. Hunting spiders with prey in their chelicerae were collected in the canopy of apple trees in organic apple orchards in Hungary during the growing seasons between 2013 and 2019 and both spiders and their prey were identified and measured. Among others, the composition of the actual (captured by spiders) and the potential (available in the canopy) prey was compared, trophic niche and food web metrics were calculated, and some morphological, dimensional data of the spider-prey pairs were analyzed. Species-specific differences in prey composition or pest control ability were also discussed. By analyzing a total of 878 prey items captured by spiders, we concluded that arboreal hunting spiders forage selectively and consume a large number of apple pests; however, spiders’ beneficial effects are greatly reduced by their high levels of intraguild predation and by a propensity to switch from pests to alternative prey. In this study, arboreal hunting spiders showed negative selectivity for pests, no selectivity for natural enemies and positive selectivity for neutral species. In the trophic web, the dominant hunting spider taxa/groups (Carrhotus xanthogramma, Philodromus cespitum, Clubiona spp., Ebrechtella tricuspidata, Xysticus spp. and ‘Other salticids’) exhibit different levels of predation on different prey groups and the trophic web’s structure changes depending on the time of year. Hunting spiders show a high functional redundancy in their predation, but contrary to their polyphagous nature, the examined spider taxa showed differences in their natural diet, exhibited a certain degree of prey specialization and selected prey by size and taxonomic identity. Guilds (such as stalkers, ambushers and foliage runners) did not consistently predict either prey composition or predation selectivity of arboreal hunting spider species. From the economic standpoint, Ph. cespitum and Clubiona spp. were found to be the most effective natural enemies of apple pests, especially of aphids. Finally, the trophic niche width of C. xanthogramma and Ph. cespitum increased during ontogeny, resulting in a shift in their predation. These results demonstrate how specific generalist predators can differ from each other in aspects of their predation ecology even within a relatively narrow taxonomic group.

Urbanization can affect arthropod abundance in different ways. While species with narrow habitat range and low dispersal ability often respond negatively to urban environments, many habitat generalist species with good dispersal ability reach high densities in city centers. This filtering effect of urban habitats can strongly influence predator-prey-mutualist interactions and may therefore affect the abundance of predatory and phytophagous species both directly and indirectly. Here, we assessed the effect of urbanization on aphids, predatory arthropods, and ants on field maple ( Acer campestre ) trees in and around the city of Budapest, Hungary. We used the percentage of impervious surfaces within a 500 m radius of each site as an index of the degree of urbanization. We found that the abundance of aphids increased with increasing level of urbanization. However, abundance of predatory arthropods and occurrence of poorly dispersing species within the predator community were negatively related to urbanization, and we identified these two independent factors as significant predictors of aphid abundances. The abundance of ants decreased with urbanization, and contrary to our expectations, did not affect the abundance pattern of aphids. Our results suggest that urbanization, by altering the abundance and composition of predator communities, can disrupt biological control of aphid populations, and thus may contribute to the aphid outbreaks on urban trees.

In the last few decades, the spiraea aphid (Aphis spiraecola Patch) has become a widely distributed pest of apple and citrus orchards across Europe. In our study, A. spiraecola was observed for the first time in Kosovo, Slovakia, the Czech Republic, the United Kingdom and Denmark, in apple orchards in the growing seasons of 2016, 2018 and 2019. The presence of A. spiraecola was also recorded on other host plants such as the quince (Cydonia oblonga Miller) and Vanhoutte spiraea (Spiraea × vanhouttei) in Slovakia, and the quince, common pear (Pyrus communis Linnaeus) and firethorn (Pyracantha coccinea M.J. Roemer) in the United Kingdom. Based on the morphological characteristics and the sequencing of the DNA mitochondrial cytochrome c oxidase subunit 1 gene (COI fragment) barcode, our study confirms the presence of this pest in five additional regions in Europe.

In the last few decades, the spiraea aphid (Aphis spiraecola Patch) has become a widely distributed pest of apple and citrus orchards across Europe. In our study, A. spiraecola was observed for the first time in Kosovo, Slovakia, the Czech Republic, the United Kingdom and Denmark, in apple orchards in the growing seasons of 2016, 2018 and 2019. The presence of A. spiraecola was also recorded on other host plants such as the quince (Cydonia oblonga Miller) and Vanhoutte spiraea (Spiraea × vanhouttei) in Slovakia, and the quince, common pear (Pyrus communis Linnaeus) and firethorn (Pyracantha coccinea M.J. Roemer) in the United Kingdom. Based on the morphological characteristics and the sequencing of the DNA mitochondrial cytochrome c oxidase subunit 1 gene (COI fragment) barcode, our study confirms the presence of this pest in five additional regions in Europe.

Circadian rhythms play an essential role in the adaptation of organisms to the environment and may show species-specific or sex-specific differences even within a closely related taxonomic group. Although spiders (Araneae) are sexually dimorphic in several morphological and behavioural features, there are very few studies on the sex-specific differences in their biological rhythms. This study evaluated the circadian rhythm in the locomotor activity of two agrobiont hunting species of spider, Carrhotus xanthogramma (Latreille, 1819) (Salticidae) and Philodromus cespitum (Walckenaer, 1802) (Philodromidae), under natural photoperiod conditions. Particular attention was paid to possible differences between the sexes in both species. We found that C. xanthogramma is a strictly diurnal species with a mean activity peak in the morning in both sexes and the females are more active than males. The locomotor activity rhythm of males was richer in ultradian (shorter than a day but longer than an hour) components, although the relative power of these components was negligible compared to the main, 24-h period component. In accordance with these results, the diel pattern of locomotor activity of C. xanthogramma can be described by a unimodal cosine curve. In contrast to C. xanthogramma, both sexes of Ph. cespitum showed cathemeral activity (i.e., activity occur within both the light and dark portions of the daily cycle) and females and males follow quite different activity schedules: females were most active at night, shortly before nautical dawn, whereas males were most active early in the morning. Unlike C. xanthogramma, Ph. cespitum has more ultradian components, with higher relative power especially in females, where besides the 24-h circadian component there is a particularly strong 12-h ultradian period. Based on these factors, females of Ph. cespitum show a bimodal and males a unimodal pattern.

We studied the effects of kaolin particle film applications on major sour cherry (Prunus cerasus L.) pests and fruit quality and evaluated the ability of cinnamon essential oil (Cinnamomum verum J. Presl) to reduce infestations by cherry fruit fly, Rhagoletis cerasi (Linnaeus 1758) (Diptera: Tephritidae), in the field. Efficacy of kaolin particle films (Surround WP, Engelhard Corporation; applied at 4% concentration) was compared at two application frequencies (one and two applications). The essential oil of cinnamon (applied at 0.25% concentration) was sprayed five times on selected trees. As the amount of damage caused by pests may vary between different parts of the canopy, both kaolin and essential oil treatments were evaluated at two canopy levels. We found that the damage of R. cerasi and stone fruit weevil, Anthonomus rectirostris (Linnaeus 1758) (Coleoptera: Curculionidae), on the fruits occurred primarily in the upper third of the canopy, while the incidence of sour cherry anthracnose caused by Colletotrichum acutatum J. H. Simmonds 1968 (Glomerellales: Glomerellaceae) was concentrated to the lower third of the canopy. Two kaolin particle film applications significantly reduced the fruit injury caused by R. cerasi by 62% (Abbott’s efficacy). In contrast, the treatments showed no activity against A. rectirostris and C. acutatum, although infestation by A. rectirostris was numerically lower on the trees treated with kaolin (19–32% efficacy). The kaolin applications did not affect the average fruit weight (g/100 cherries) and soluble solid content (SSC, %). The cinnamon essential oil applications did not control infestations by R. cerasi. Overall, our results suggest that kaolin particle film technology is a promising tool in pest management programs in organic sour cherry production, at least against R. cerasi.

This study reports the first records of two spider species for Hungary: Cyclosa sierrae Simon, 1870 (Araneidae) and Porrhomma oblitum (O. P.-Cambridge, 1871) (Linyphiidae). Cyclosa sierrae also represents the first record of this species from Central Europe. Furthermore, we also provide evidence about the occurence of Dysdera lata Reuss, 1834 and Philodromus marmoratus Kulczyński, 1891 in Hungary, and for six further species we report new data: Brigittea vicina (Simon, 1873) (Dictynidae), Iberina microphthalma (Snazell & Duffey, 1980) (Hahniidae), Mermessus trilobatus (Emerton, 1882) (Linyphiidae), Pulchellodromus ruficapillus (Simon, 1885) (Philodromidae), Lasaeola prona (Menge, 1868) (Theridiidae) and Diaea livens Simon, 1876 (Thomisidae). Comments on the distribution, biology and taxonomy of the ten mentioned spider species are provided.

Two Mediterranean Auchenorrhyncha species, the planthopper Latilica maculipes (Melichar, 1906) and the leafhopper Synophropsis lauri (Horváth, 1897) are reported for the first time from Hungary. With 2 figures

The presence of Psallus assimilis Stichel, 1956 (Hemiptera: Heteroptera: Miridae) is reported for the first time from Hungary. Specimens were collected from the canopy of field maple (Acer campestre L.) trees in Budapest, Diósd and Törökbálint in spring of 2015, 2016 and 2017. Our study indicates that P. assimilis is one of the most abundant heteropteran species in the canopy of field maple trees not only in suburban and urban forests but also on individual stree

Climate change is altering the phenology of trophically linked organisms, leading to increased asynchrony between species with unknown consequences for ecosystem services.Although phenological mismatches are reported from several ecosystems, experimental evidence for altering multiple ecosystem services is hardly available.We examined how the phenological shift of apple trees affected the abundance and diversity of pollinators, generalist and specialist herbivores and predatory arthropods.We stored potted apple trees in the greenhouse or cold store in early spring before transferring them into orchards to cause mismatches and sampled arthropods on the trees repeatedly.Assemblages of pollinators on the manipulated and control trees differed markedly, but their overall abundance was similar indicating a potential insurance effect of wild bee diversity to ensure fruit set in flower-pollinator mismatch conditions.Specialized herbivores were almost absent from manipulated trees, while less-specialized ones showed diverse responses, confirming the expectation that more specialized interactions are more vulnerable to phenological mismatch.Natural enemies also responded to shifted apple tree phenology and the abundance of their prey.While arthropod abundances either declined or increased, species diversity tended to be lower on apple trees with shifted phenology.Our study indicates novel results on the role of biodiversity and specialization in plant-insect mismatch situations.

Climate change is altering the phenology of trophically linked organisms, leading to increased asynchrony between species with unknown consequences for ecosystem services. Although phenological mismatches are reported from several ecosystems, experimental evidence for altering multiple ecosystem services is hardly available. We examined how the phenological shift of apple trees affected the abundance and diversity of pollinators, generalist and specialist herbivores and predatory arthropods. We stored potted apple trees in the greenhouse or cold store in early spring before transferring them into orchards to cause mismatches and sampled arthropods on the trees repeatedly. Assemblages of pollinators on the manipulated and control trees differed markedly, but their overall abundance was similar indicating a potential insurance effect of wild bee diversity to ensure fruit set in flower-pollinator mismatch conditions. Specialized herbivores were almost absent from manipulated trees, while less-specialized ones showed diverse responses, confirming the expectation that more specialized interactions are more vulnerable to phenological mismatch. Natural enemies also responded to shifted apple tree phenology and the abundance of their prey. While arthropod abundances either declined or increased, species diversity tended to be lower on apple trees with shifted phenology. Our study indicates novel results on the role of biodiversity and specialization in plant-insect mismatch situations.

We report the first record of Icius subinermis Simon, 1937, one female, from Budapest, Hungary. We provide photographs of the habitus and of the copulatory organ. The possible reasons for the new record and the current jumping spider fauna (Salticidae) of Hungary are discussed. So far 77 salticid species (including I. subinermis) are known from Hungary.

Landscape composition may influence biodiversity and ecosystem services in agricultural fields. Hitherto, most studies have focused on annual crops and the available information on the impacts of landscape structure in orchards is sparse. In this study, we evaluated the effects of pesticide use as cumulative toxicity on pest and predatory beetle (Coleoptera) assemblages in the canopy of apple orchards surrounded by different proportion of semi-natural vegetation, crop fields and settlements in Hungary. Laboratory data suggest that increasing pesticide toxicity negatively affects predators (coccinellids), but we did not find such a pattern. Supposedly, the effect of pesticides was masked by the continuous recolonisation of orchards from the surrounding landscape. On the contrary, for the less mobile pest species [Anthonornus pomorum, Phyllobius oblongus (Curculionidae)] we did find a decline in abundance along the gradient of increasing pesticide toxicity. Landscape composition around the orchards significantly influenced the abundance of predatory, fungivorous and tourist species, but had no effect on pests. Contrary to expectations, however, semi-natural habitats had a minor effect compared to arable fields, orchards and settlements which habitat types had various effects on the abundance of different coleopteran groups and species. For example, Harmonics axyridis (Coccinellidae) abundance was positively affected by its overwintering sites, i.e. human settlements in spring, semi-natural forests in summer, and arable fields in autumn. The mass immigration of other predatory, fungivorous and tourist species from the surrounding arable fields into the orchards started from July with senescence and harvesting of arable crops. These results suggest that arable fields, other orchards and settlements might be more important sources of colonisation for natural enemies in orchards than certain semi-natural habitats.