Influence of selected biogenic amines on development and demographic parameters of a temperate population of Cinara (Cupressobium) cupressi (Hemiptera, Aphididae)

Cinara (Cupressobium) cupressi, the cypress aphid, is a serious pest of Cupressus spp. and other Cupressaceae, considered to be one of the world’s 100 worst invasive alien species. The potential influence of selected biogenic amines (tryptamine, tyramine, putrescine, and cadaverine) on development and demographic parameters of a temperate population of the cypress aphid was investigated under laboratory conditions. Within parthenogenetic generations, the use of biogenic amines resulted in a significant reduction in the total fecundity and the average daily fecundity both in the fundatrix (F0) and the fundatrigeniae (F1), whereas this influence in the F5 generation was insignificant. In all parthenogenetic generations treated with amines, the dissected female abdomen contained a greater number of mature embryos compared to control samples. Cadaverine caused marked changes in the body length of all viviparous generations studied and a significant reduction in the number of developing embryos, compared to the control sample. The use of biogenic amines did not significantly affect the number of eggs produced by oviparous females but had an impact on their lifespan. Our results indicate that biogenic amines application may disrupt feeding behavior and thus leads to reduced fecundity, consistent with the observation of reduced embryo production. Consequently, bioamines can be used as an alternative agents to control this important pest species

How Biotic Differentiation of Human Impacted Nutrient Poor Deciduous Forests Can Affect the Preservation Status of Mountain Forest Vegetation

A significant loss of biodiversity resulting from human activity has caused biotic homogenisation to become the dominant process shaping forest communities. In this paper, we present a rare case of biotic differentiation in European temperate deciduous forest herb layer vegetation. The process is occurring in nutrient poor oak-hornbeam forests in mountain areas (Polish Eastern Carpathians, Central Europe) where non-timber use was converted into conventional forest management practice. This change contributed to increases in the nitrogen content and pH reaction of the soil that, contrary to predominant beliefs on the negative impact of habitat eutrophication on diversity, did not result in a decrease in the latter. We discuss possible reasons for this phenomenon that indicate the important role of tree stand composition (an increasing admixture of beech worsening the trophic properties of the soil). The second issue considered involves the effect of the changes in herb species composition of oak-hornbeam forest on its distinctiveness from the beech forest predominating in the Polish Eastern Carpathians. Unfortunately, despite the increase in the species compositional dissimilarity of oak-hornbeam forest, a reduction in their distinctiveness in relation to the herb species composition of beech forest was found. Such a phenomenon is an effect of the major fragmentation of oak-hornbeam forests, a spread of beech forest-type species, and forest management that gives preference to beech trees. Consequently, it can be expected that changes occurring in oak-hornbeam forest vegetation will contribute to a decrease in the forest vegetation variability at the regional scale

Metabolic Response of Aphid Cinara tujafilina to Cold Stress

Climate changes enable thermophilic insect species to expand their ranges, but also force them to adapt to unfavourable environmental conditions in new habitats. Focusing on Cinara tujafilina, we investigated the metabolic changes in the body of the aphid that enabled it to survive the low temperatures of winter. Using GC–MS analysis, differences in the chemical composition of the aphids in summer and winter were found. The metabolic changes were mainly related to the increased activity of the pathways of carbohydrate metabolism, such as glycolysis and the pentose phosphate pathway; a decrease in tricarboxylic acid cycle (TCA); accumulation of polyols; and increased levels of proline, tyrosine, and fatty acids

Impact of Forest Management on the Temporal Dynamics of Herbaceous Plant Diversity in the Carpathian Beech Forests over 40 Years

In recent years, there has been a growing awareness of the complex dependence of herbaceous plant diversity on forest structure and management. However, among the studies presented so far, those in which the chronosequence (approach based on the assumption of space-for-time substitution) was used, dominate. On the other hand, it is rare to find results based on long-term research on permanent or semi-permanent sampling plots. The aim of this study was to recognize the changes in the vegetation composition and dynamics of various indices of herbaceous plant diversity over 40 years of forest development, and their dependence on forest structure and management. Here we analyzed the temporal dynamics of herbaceous plant diversity in Carpathian fertile beech forests, based on datasets recorded on semi-permanent plots in three censuses (the 1970s, 2000s and 2010s). We checked the temporal changes in alpha, beta, and gamma diversity. Analyses of the plant diversity were performed on the background of changes in forest structure and management systems. We found that the within-plot (alfa diversity) and between-plot (beta diversity) herbaceous plant diversity metrics showed inconsistent patterns along with changes in the forest structure, management systems, and intensity of forest management, during the last 40 years. Temporal changes in the gamma diversity followed the changes in alpha diversity. Although the beta diversity after 40 years is greater than in the past, we argue that the conservation status of habitats typical for well-preserved fertile mountain beech forests has deteriorated due to a decline in the sharing of the diagnostic species of these forests. We showed the importance of the different temporal interactions between the forest structure and management for herbaceous plant diversity. We argue that, in view of the complexity of these processes, it would be a mistake to reject or prioritize alpha or beta diversity measurements to determine the real course of long-term changes in herbaceous plant diversity and to properly assess the state of the forest biodiversity, their conservation status, or conservation action plans. In addition, we need far more data from long-term observations to fully understand the possible relationship patterns between the factors controlling the forest structure and plant diversity

The Impact of Changes in Species Richness and Species Replacement on Patterns of Taxonomic Homogenization in the Carpathian Forest Ecosystems

The Carpathians are Eastern Europe’s largest contiguous forest ecosystem and a hotspot of biodiversity. However, not much is known about changes in species diversity in these forests. Here we investigate the long-time changes in the diversity of plant communities in the Eastern Carpathian beech forests. We also inquire about the similarity of plant communities between managed and protected forests. We conduct our analyses using not only the broad-sense measure of changes in β diversity (βsor) but also the measures that reveal whether the changes result from spatial turnover (βsim) or nestedness (βnes). Our study demonstrated that the mean species richness did not significantly change over time in both forest types. However, we found a significant decrease of species diversity in protected forests and the same trend, but on a smaller scale, in managed forests. In both forest types the decrease of species diversity was mainly caused by spatial turnover, while nestedness-related changes were relatively small. However, the direction of changes in βnes differed in managed and unmanaged forests in such a way that it reduced the decrease of species diversity in managed forests and amplified the decrease of species diversity in unmanaged forests. We discuss our findings in terms of biotic homogenization

Changes in Chemical Composition and Accumulation of Cryoprotectants as the Adaptation of Anholocyclic Aphid <i>Cinara tujafilina</i> to Overwintering

One of the consequences of climate change is the expansion of insects’ ranges. Colonization of new habitats forces insects to adapt to new conditions, such as low temperatures in winter. Cinara tujafilina is a thermophilic anholocyclic aphid species, which reproduce exclusively parthenogenetic throughout the year, including winter. On the areas where the populations of C. tujafilina had expanded, it demonstrated its adaptation for surviving colder winters. Based on analyses of changes in body chemical composition using Fourier transform infrared (FTIR) and changes in cryoprotectant content using high performance liquid chromatography (HPLC), we showed how aphid C. tujafilina adapted to overwintering as an active stage. In the FTIR spectrum of the winter type of C. tujafilina, higher peak values originating from the carbohydrates, proteins and lipids, were observed. Glucose, trehalose, mannitol, myo-inositol and glycerol were identified in the aphid body in winter as main putative cryoprotectants to increase the insects’ tolerance to cold. The complex sugar-polyol cryoprotectant system facilitates aphids’ survival in unfavorable low temperatures

Population Development of Alien Gall-Forming Aphid <i>Tetraneura nigriabdominalis</i> on <i>Ulmus minor</i> and <i>Ulmus glabra</i>

Tetraneura (Tetraneurella) nigriabdominalis (Sasaki, 1899) is a holocyclic and heteroecious species widely distributed throughout the world. Its primary hosts are various elm species, on which it forms galls. The results of this study complement those of previous research on the development of T. nigriabdominalis on primary hosts. Our research was conducted on two elm species, Ulmus minor and Ulmus glabra, at three locations and for three successive seasons between 2017 and 2019. Fundatrices hatched between 27 April and 12 May. The first galls were observed 6–8 days after the hatching date of the fundatrices. On average, there were 1–7.5 galls on one leaf. The highest abundances of T. nigriabdominalis galls were found in the medial and basal parts of the leaf blades. The fundatrices matured within 12–21 days after hatching and produced nymphs within 2–3 weeks. The fecundity of the fundatrices was influenced by the temperature in April, the size of the laminae, and the size of the galls. The females developing on U. glabra were more fecund (2–58 nymphs), whereas those developing on U. minor produced 1–29 nymphs. The winged migrants of the second generation appeared between late May and late June, when the first cracks on the galls were also observed. The entire development of two aphid generations on the primary host was temperature-dependent and lasted from four to almost six weeks. Our results show that U. glabra and U. minor are suitable hosts for T. nigriabdominalis. The development of aphids proceeded similarly on both tree species. Temperature, especially in April, significantly influenced the duration of individual developmental phases and the fecundity of fundatrices

Population Development of Alien Gall-Forming Aphid Tetraneura nigriabdominalis on Ulmus minor and Ulmus glabra

Tetraneura (Tetraneurella) nigriabdominalis (Sasaki, 1899) is a holocyclic and heteroecious species widely distributed throughout the world. Its primary hosts are various elm species, on which it forms galls. The results of this study complement those of previous research on the development of T. nigriabdominalis on primary hosts. Our research was conducted on two elm species, Ulmus minor and Ulmus glabra, at three locations and for three successive seasons between 2017 and 2019. Fundatrices hatched between 27 April and 12 May. The first galls were observed 6&ndash;8 days after the hatching date of the fundatrices. On average, there were 1&ndash;7.5 galls on one leaf. The highest abundances of T. nigriabdominalis galls were found in the medial and basal parts of the leaf blades. The fundatrices matured within 12&ndash;21 days after hatching and produced nymphs within 2&ndash;3 weeks. The fecundity of the fundatrices was influenced by the temperature in April, the size of the laminae, and the size of the galls. The females developing on U. glabra were more fecund (2&ndash;58 nymphs), whereas those developing on U. minor produced 1&ndash;29 nymphs. The winged migrants of the second generation appeared between late May and late June, when the first cracks on the galls were also observed. The entire development of two aphid generations on the primary host was temperature-dependent and lasted from four to almost six weeks. Our results show that U. glabra and U. minor are suitable hosts for T. nigriabdominalis. The development of aphids proceeded similarly on both tree species. Temperature, especially in April, significantly influenced the duration of individual developmental phases and the fecundity of fundatrices