Morphometric variation of Abax parallelepipedus (Piller & Mitterpacher, 1783), (Coleoptera: Carabidae) in rural – urban areas

© Slovak University of Agriculture in Nitra Faculty of Agrobiology and Food Resources


Introduction
Studies of morphometric features changed due to environmental factors necessary to improve species populations' dynamics and structure. The interpretation of Community and species-specific responses require to be linked to the landscape characteristics of the urban and rural gradient to be applied in terms of disruptive features (Niemelä and Kotze, 2009;Oboňa et al., 2017;Oboňa et al., 2019;Demková et al., 2018). The high adaptive capacity of Abax parallelepipedus has allowed the species to spread to more of Europe, making it dominant for geophilic carabids of the forestry assemblages (Huidu, 2011(Huidu, , 2012. Two factors influence the change in body size along urban and rural gradients. The first is the expansion of urban areas and the related impact of urbanization on wildlife. The second is the integrity of body size as a sign that affects many life situations, e.g., ontogenesis, sexual selection, fertility, predatory type size, quality and availability of resources, competition (Angilletta and Dunham, 2003;Dial et al., 2008). Carabidae is a family of Coleoptera often used to study changes in the environment. The advantage is a good knowledge of ecological demands concerning species inhabiting different habitats; some are stenovalent. This family is sensitive to various toxic substances (e. g., herbicides, insecticides), changes in soil pH and soil moisture (Heydeman, 1955;Bezděk, 2001;Ivanič Porhajášová et al., 2018a, 2018b, Oboňa and Stašiov, 2018. The influence of urban, suburban, and rural areas on body size was analyzed by Sukhodolskaya (2013); Saveliev (2014, 2016). Studies have shown morphometric variations in the urbansuburban-rural gradient. The authors detected greater body length in Carabus cancellatus, Poecilus cupreus and Pterostichus melanarius occurring in rural areas. The suburban environment did not significantly affect body length changes in the above species. In the earlier studies (Gordienko and Sukhodolskaya, 2011;   pointed out a reduction in elytron length, pronotum width, and head width in Carabus cancellatus inhabiting the urban environment. However, the width of the elytron increased. Several authors (Wheller, 1996;Naidenko and Grechkanev, 2002;Timofeeva and Savosin, 2009) confirmed a reduction of body length in the direction of the species' urbanization gradient Carabus nemoralis, C. aeruginosus, and Pterostichus oblongopunctatus. According to Rueffler et al. (2006), the asymmetry of morphometric features is one indicator of selection in the population. Brygadyrenko and Reshetniak (2014) dealt with the asymmetry of morphometric features in Harpalus affinis sampled from the forest, field, and steppe ecosystems. They noticed a significant negative asymmetry of some characters: body length, head length, elytra length, eye distance, head width, prothorax width between anterior and posterior angles, elytra width between humeral angles, and maximum elytra width in females, indicating their shortening.

Morphometric variation of Abax parallelepipedus (Piller & Mitterpacher, 1783), (Coleoptera: Carabidae) in rural -urban areas
The first to use the term Ellipsoid biovolume (EV) to determine the body size (volume) of Carabidae family were Braun et al. (2004). The EV is calculated from the morphometric features of individuals (length, thickness, and width). The Carabidae family is suitable for calculating EV due to their morphology characterization by a relatively large ellipsoid body size (Barndt et al., 1991;Turín, 2000). In the study of ground beetles (Carabidae) during the restoration of the pine forest, Szyszko (1983) formulated and confirmed the hypothesis that "the decrease of environmental disturbance allows a larger than average body size." Šustek (1987) pointed out the declining body size of Carabidae in anthropically intensively disturbed areas. According to Niemelä et al. (2002), urbanization causes a decrease in the biodiversity of Carabidae species and, in the most cases, increases the number of small species towards the city center.
Similarly, Weller and Ganzhorn (2006) state a decrease in body size of Carabus nemoralis due to urbanization towards the city center. Magura et al. (2006) also examined differences in the Carabidae species' body size in rural, urban, and suburban areas. In the urban environment, authors noticed several species with larger body size than in urban and suburban areas. Lövei and Magura (2006) found that the body size of carnivorous Carabidae decreased near the industrial area. In less polluted environments, a change in body size was not observed.
This study was focused on the analysis of variables of morphometric features (length, height and width) species Abax parallelepipedus, during the years 2015-2017. The (EV) in the studied 2 forest localities and 2 waterside vegetationin (4 localities) the southern part of central Slovakia was also evaluated.

Material and methods
The research took place from 2015 to 2017, from April to November, in 4 localities and 3 types of biotopes, according to Ružičková et al. (1996). The study areas are located in the southern part of Central Slovakia (geomorphological units Stolické vrchy Mts. and Juhoslovenská kotlina basin). Location data and habitat characteristics of localities are summarized in Table 1.
Material from pitfall traps at regular biweekly intervals was collected. We used pitfall traps (750 ml) (Novák et al., 1969). Five pitfall traps were arranged in 1 line per each locality and 10 m away from each other. As a preservation, 4% NaCl was used. The species of Abax parallelepipedus were determined according to Hůrka (1996).

Computation of the Carabidae Ellipsoid biovolume (EV)
The morphometric variables were measured for each individual using a digital microscope (0.1 mm accuracy): a) the length -dorsal length between the upper lip (labium) and the terminal part of elytra, b) the width -dorsal length between the maximum width of the elytra, Each parameter was measured three times to minimize error, and the final value is their arithmetic average. For each specimen, the Elipsoid biovolume was calculated from morphometric data according to Braun et al. (2004): where: L -individual length; H -individual height; Windividual width

Database quality
The data of the obtained research was saved and performed using a Microsoft SQL Server 2017 database (Express Edition). It consisted of frequency tables for collections, measured morphometric features, and EV. The database also consisted the code tables for localities and their variables (habitat, locality name, cadastral area, altitude, coordinates of localities), species, and bioindication characteristics. Matrices for statistical calculations were programmed using Microsoft SQL Server Management (SSMS, 2017).

Statistical analyses
The spatial modeling was performed by multivariate analysis using Canoco program 5 (Ter Braak and Šmilauer, 2012), with which we look for dependencies Ellipsoid biovolume of Abax parallelepipedus. Based on the lengths of the gradient (using Detrended Correspondence Analysis -DCA), we used the unimodal method of Canonical Correspondence Analysis -CCA analysis to evaluate the material.
The analysis in the statistical program Statistica Cz. Ver. 7.0 (StatSoft, Inc., 2004) was focused on Shapiro-Wilk W-test, which determines the normality of data distribution. Based on the violation of the normality data distribution (p-value = 0.00) we used a nonparametric Kruskal-Wallis test (ANOVA), and Friedman test (ANOVA) were used to test the differences in EV, length, height, and width of the body between areas (rural, urban landscape). Using the regression model (Polynomial regression), we expressed the relationship (correlation) between EV's average value per individual to the years of harvest for urban and rural areas.
Based on the violation normality of the data distribution, we used a nonparametric Kruskal-Wallis test (ANOVA) to confirm the statistically significant difference (p-value = 0.037), in EV's average values in the species Abax parallelepipedus between urban and rural areas (Figure 1). Lower EV values for rural areas may be affected by former glass production near these localities, where habitat damage has occurred. Similarly, Braun et al. (2004), Lövei and Magura (2006) observed decreased body size due to industrial production.
Based on the violation of the normality data distribution, we used a nonparametric Friedman test (ANOVA) to confirm the statistically significant difference (p-value = 0.01) (Figure 2) difference between the average values of EV urban and rural areas in 2015-2017. In the rural area, we recorded a slight year-on-year decline between 2016 and 2017. On the contrary, in the urban area, were recorded between 2016 and 2017, of up to 70 mm 3 . In accordance with our results, many studies (Szyszko, 1983;Šustek, 1987;Niemelä et al., 2002;Magura et al., 2006;Weller and Ganzhorn, 2006) state the body size (EV) reduction in anthropically intensively disturbed areas due to urbanization.
The spatial variability (dispersion) of the species Abax parallelepipedus was determined by Canonical Correspondence Analysis (CCA, SD = 4.01 on the 1 st ordination axis). The explained cumulative variability

Conclusions
In 2015  of species data values was 60% on the 1 st ordination axis and 80.2% on the second ordination axis. Cumulative variability of the species set explained by environment variables captured by the 1 st ordination axis 63%, and the second axis captures 87.9%. The distance of vectors between the years 2015-2016 was small (Figure 3). On the contrary, in 2016-2017 was the distance large, which indicates a significant change in the dispersion between these years (2016)(2017). We assumed that the above facts may be affected by a change in the food supply influenced by climatic conditions (temperature, sum of difficulties).
The correlation coefficient value was very high for the urban (r = 0.8810), which indicated a solid relationship. A medium value (r = 0.6653) was observed in the rural area, indicating a medium relationship of the measured average EV values per individual to the years of harvest.