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1.
We investigated ground beetle communities (Coleoptera, Carabidae) in ancient woodland remnants in north-western Lower Saxony, Germany. A total of 90 pitfall traps was exposed in a stratified design in 10 stands of mature oak–beech and oak–hornbeam forests in the year 2003. Overall, 47 species (10,676 individuals) were recorded. Among these were the two relict species Carabus glabratus and Abax parallelus, and 14 further eurytopic forest species. Eleven species exhibited a high frequency and were found in all of the ten stands. Multiple linear regressions showed several significant relationships at two scales for species richness of different groups of carabids and for several of the measured environmental factors. Forest area, litter depth, amount of dead wood, distance to forest edge, and soil moisture were found to be key factors determining species richness. Furthermore, recent disturbance by logging reduced the number of forest species. According to direct gradient analyses soil moisture and litter depth have greatest influence on species communities of both, forest species and widespread species. Habitat suitability models for the two recorded relict species, A. paralellus and C. glabratus, were developed using logistic regression. The presence of A. parallelus in the mature ancient woodland remnants depends mainly on higher values of soil moisture, whereas for C. glabratus none of the measured environmental variables appeared to be key factors. Implications for the conservation of carabid assemblages in mature ancient woodlands include the advice to spread out logging over long periods of time and over various woodlands in order to keep the stand disturbance at a long-term low level. Variation in logging practices may help to conserve diverse structures. Afforestation with non-native tree species should be avoided in the managed ancient woodlands. Finally, especially the preservation of a high soil moisture seems to be important to conserve typical carabid communities.  相似文献   

2.
Carabus (Cathoplius) aliai was described as a separate species by Escalera in 1944 but since the 1950–60s it has been considered as a subspecies of Carabus (Cathoplius) stenocephalus Lucas, 1866. This downgrading was adopted after examining only a few specimens, due to their rarity in collections. In recent years, an important population of this taxon was rediscovered in the Tan-Tan area in southern Morocco. By combining field observations with laboratory breeding experiments including hybridization trials, and through the morphological examination of a representative number of individuals, it is confirmed that Carabus aliai is indeed a valid species. Despite close geographic distribution, the morphological and biological characteristics of Carabus aliai and Carabus stenocephalus ifniensis Zarco, 1941, its northern substitutive taxon, are very different. Carabus aliai adults are characterized by a smaller size, a slender silhouette, a more brilliant aspect, a narrower pronotum, a coarser elytral sculpture, longer legs, and a wider and a little more curved apex of the median lobe of the aedeagus. Carabus aliai larvae are also characterized by a much smaller size and the Carabus aliai pupa has a narrower thoracic area and a different chaetotaxy compared to that of Carabus stenocephalus ifniensis. Contrary to this, Carabus aliai has a life cycle belonging to the annual univoltine winter semelparous type. Moreover, the duration of its development cycle is shorter. Carabus aliai is a sabulicolous steppe-wandering species with an intensive running activity, while Carabus stenocephalus ifniensis is a more sedentary taxon. Crossbreeding experiments showed a marked reproductive isolation between Carabus aliai and Carabus stenocephalus ifniensis. When F1 hybrids were crossed with one another, a very high mortality rate during embryonic, larval and pupal development was evident and no vital F2 neo-adults were obtained. Morphological and biological differences, together with the reproductive failure in Carabus aliai × Carabus stenocephalus ifniensis hybrids, clearly indicate that Carabus aliai is a separate Cathoplius species that is distributed in an area south of the Anti-Atlas chain, from Plage Blanche (Guelmim) to Lemsid and Bou Kra (south of Laâyoune). Carabus aliai is therefore both a Saharan desert endemic and an Atlantic resident. Moreover, it is the southernmost Carabus species of the western Palaearctic region.  相似文献   

3.
In carabid beetles, physiological and behavioural characteristics reflect specific habitat demands and there is a strong correlation between body form and habit in species with different life style. In this study, we compared the morphometry and compound eye characteristics of three species of the genus Siagona: Siagona jenissoni, Siagona dejeani and Siagona europaea. These carabids have a stenotopic lifestyle in Mediterranean clayey soils, inhabiting the ground fissure system formed during the dry season. All species have a Mediterranean distribution and are nocturnal olfactory hunters, and are strict ant predators. For morphometric measurements, we considered body length (mm), wing length (mm), antenna length (mm), head width (mm), trochanter length (mm), number of ommatidia, eye surface area (mm2), ommatidia density (number of ommatidia/mm2 of eye surface area), head height (mm), thorax height (mm) and abdomen height (mm). The data revealed intersexual and interspecific differences. The three species differ in relative length of the antennae, density and number of ommatidia and relative trochanter length. Significant differences occurred in wing sizes, which are well developed in Siagona europaea, the only species capable of flight. When eye size is compared with other ground beetles of various lifestyles, Siagona shows pronounced "microphthalmy" an adaptation to subterranean life in clayey crevices of tropical and subtropical climates with a marked dry season.  相似文献   

4.
The risks of gene flow between interfertile native and introduced plant populations are greatest when there is no spatial isolation of pollen clouds and phenological patterns overlap completely. Moreover, invasion probabilities are further increased if introduced populations are capable of producing seeds by selfing. Here we investigated the mating system and patterns of pollen-mediated gene flow among populations of native ash (Fraxinus excelsior) and mixed plantations of non-native ash (F. angustifolia and F. excelsior) as well as hybrid ash (F. excelsior × F. angustifolia) in Ireland. We analysed the flowering phenology of the mother trees and genotyped with six microsatellite loci in progeny arrays from 132 native and plantation trees (1493 seeds) and 444 potential parents. Paternity analyses suggested that plantation and native trees were pollinated by both native and introduced trees. No signs of significant selfing in the introduced trees were observed and no evidence of higher male reproductive success was found for introduced trees compared with native ones either. A small but significant genetic structure was found (φft=0.05) and did not correspond to an isolation-by-distance pattern. However, we observed a significant temporal genetic structure related to the different phenological groups, especially with early and late flowering native trees; each phenological group was pollinated with distinctive pollen sources. Implications of these results are discussed in relation to the conservation and invasiveness of ash and the spread of resistance genes against pathogens such as the fungus Chalara fraxinea that is destroying common ash forests in Europe.  相似文献   

5.
Dostal A 《ZooKeys》2011,(132):33-50
The subgenus Semiclivina Kult, 1947 of Clivina Latreille, 1802 (sensu lato) has been re-ranked as a genus, with the most readily observed feature being the stridulation organ of the proepisterna and front femora. A group of species within Semiclivina is characterized by a peculiar acute tubercle at the posterior margin of the eye, which corresponds to an equally noticeable incision of the anterior margin of the pronotum. This group is considered as monophyletic and placed as such in the subgen. n.Uroclivina. The species Semiclivina (Uroclivina) bergerisp. n. from Argentina and southern Brazil and Semiclivina (Uroclivina) schmidisp. n. from French Guyana are described. The following additional species are included in Uroclivina: Clivina urophthalmoides (Kult, 1947) new combination, Clivina urophthalma (Putzeys, 1863) new combination, and Clivina oxyomma (Putzeys, 1868) new combination. The two subgenera of Semiclivina Kult, and the current five species of Uroclivina are differentiated in a key.  相似文献   

6.
7.
Five new species of the genus Chydaeus Chaudoir, 1854 are described from China: Chydaeus fugongensissp. n. (Shibali, Fugong County, Yunnan Province), Chydaeus gutangensissp. n. (Gutang, Medog County, Xizang Autonomous Region [Tibet]), Chydaeus hanmiensissp. n. (Hanmi, Medog County, Xizang Autonomous Region [Tibet]), Chydaeus asetosussp. n. (NE of Fugong, Yunnan Province), and Chydaeus baoshanensissp. n. (N of Baoshan, Yunnan Province). Taxonomic and faunistic notes on eleven other species occurring in Xizang and Yunnan are also provided. Chydaeus shunichii Ito, 2006 is re-described, based on specimens from Lushui County, Yunnan. Chydaeus kumei Ito, 1992 is treated as a subspecies of Chydaeus andrewesi Schauberger, 1932 [NEW STATUS]. The taxonomic status of Chydaeus guangxiensis Ito, 2006 is discussed. The following taxa are recorded from China for the first time: Chydaeus obtusicollis Schauberger, 1932 (Xizang and Yunnan), Chydaeus malaisei Kataev & Schmidt, 2006 (Yunnan), Chydaeus semenowi (Tschitschérine, 1899) (Xizang and Yunnan), Chydaeus andrewesi andrewesi Schauberger, 1932 (Xizang and Yunnan), Chydaeus andrewesi kumei Ito (Yunnan), Chydaeus bedeli interjectus Kataev & Schmidt, 2002 (Xizang), and Chydaeus bedeli vietnamensis Kataev & Schmidt, 2002 (Yunnan).  相似文献   

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