Third-stage larvae of the nematode Serpinema trispinosum (Leidy, 1852) were collected from the midgut of four of five species of adult damselflies (Zygoptera) from a non-irrigated restored semipermanent wetland located in Stillwater, Oklahoma, USA. Of the four infected damselfly species, prevalence and mean abundance was highest for the southern spreadwing, Lestes disjunctus australis Walker (10%, 0.2 ± 0.8) and lowest for the familiar bluet, Enallagma civile (Hagen) (2.5%, 0.04 ± 0.3); whereas mean intensities were lowest for the citrine forktail, Ischnura hastata (Say) (1.5 ± 0.5) and the eastern forktail, Ischnura verticalis (Say) (1.0 ± 0). This is the first record of larvae of S. trispinosum from damselflies. Serpinema trispinosum adults have been reported from 18 species of North and Central American freshwater turtles, whereas microcrustaceans such as copepods serve as intermediate hosts and snails, fish and amphibians serve as paratenic hosts in this nematode's life cycle. However, dietary studies of the 18 species of freshwater turtles reported as definitive hosts for S. trispinosum indicate that aquatic insects including damselflies are more commonly reported in turtle diets than are fish or amphibians. Additionally, unlike snails and amphibians, larval damselflies predominantly feed on microcrustaceans, and our observation of S. trispinosum infecting damselflies may reflect the importance of these insects as paratenic hosts. In the present study, we provide new host information and measurements for third-stage larvae of S. trispinosum from damselfly hosts along with measurements for adult male and female S. trispinosum from turtle hosts from Oklahoma, USA., Crystal M. Wiles, Matthew G. Bolek., and Obsahuje bibliografii
The expansion of urban areas is one of the most significant anthropogenic impacts on the natural landscape. Due to their sensitivity to stressors in both aquatic and terrestrial habitats, dragonflies and damselflies (the Odonata) may provide insights into the effects of urbanisation on biodiversity. However, while knowledge about the impacts of urbanisation on odonates is growing, there has not been a comprehensive review of this body of literature until now. This is the first systematic literature review conducted to evaluate both the quantity and topics of research conducted on odonates in urban ecosystems. From this research, 79 peer-reviewed papers were identified, the vast majority (89.87%) of which related to studies of changing patterns of biodiversity in urban odonate communities. From the papers regarding biodiversity changes, 31 were performed in an urban-rural gradient and 21 of these reported lower diversity towards built up city cores. Twelve of the cases of biodiversity loss were directly related to the concentrations of pollutants in the water. Other studies found higher concentrations of pollutants in odonates from built-up catchments and suggested that odonates such as Aeshna juncea and Platycnemis pennipes may be candidate indicators for particular contaminants. We conclude by identifying current research needs, which include the need for more studies regarding behavioural ecology and life-history traits in response to urbanisation, and a need to investigate the mechanisms behind diversity trends beyond pollution., Giovanna Villalobos-Jiménez, Alison M. Dunn, Christopher Hassall., and Obsahuje bibliografii