Daily rhythmicity in the sexual behaviour of Monema flavescens Walker (Lepidoptera: Limacodidae) was studied under laboratory conditions. There was a distinct diel periodicity in female calling, male responsiveness and mating behaviour of M. flavescens. As females aged there was an advance in the onset and more time spent calling. One day old females started calling 4 h after the onset of the scotophase, and 5 to 6 day old females called during the first hour of the scotophase. About 34.5% of females called on the night they emerged (1 day old) and the peak in calling of 97.8% was recorded for 2 day old females, after which the incidence of calling decreased rapidly with advancing age. Wind tunnel and copulation tests showed that males were sexually mature on the third night and female moths on the second night. The highest value for the percentage mating was recorded for 3 day old virgin females 4 to 6 h after the onset of the scotophase. In field tests, traps baited with 2 day and 3 day old virgin females captured more males than any other trap and most males were captured 4 to 6 h (1 to 2 day old), 3 to 5 h (3 to 4 day old) and 2 to 4 h (5 to 6 day old) after the onset of the scotophase. These results indicate that there is a daily rhythm in the reproductive behaviour of M. flavescens and provides a better understanding of its sexual behaviour.
Studies of insect population under field conditions to establish survival rates, longevity and dispersal rates are rare in the literature. These types of studies are important and can be used to inform studies of the effects of landscape composition and configuration on levels of biodiversity. Here the Cantharidae beetle, Rhagonycha fulva is studied under field conditions to derive estimates of daily survival rates for both males and females as well as local dispersal rates. Survival was studied at two sites, one in Wales and another in England, whilst dispersal was examined only at the Welsh site. Beetles were marked using different coloured enamel paints at the mid-point of a 200 m linear transect. The beetles were almost exclusively found (and marked) on common hogweed, Heracleum sphondylium. No difference in survival was found between males and females at both of the sites. The survival rates found at the two sites also did not differ. The overall daily survival rate was 0.771 equating with a median longevity of 4.37 days. Casual observations yielded a small number of marked individuals in excess of 400 m away from the point of marking. Movement of males along the transect differed from females. Marked females were never found far from the point of marking whilst males moved further away with time. This difference in behaviour is discussed in terms of hypothesized insect dispersal behaviour following emergence as mobile adults., Laura E. Rodwell, Jennifer J. Day, Christopher W. Foster, Graham J. Holloway., and Obsahuje bibliografii
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 stubborn decision of the Latvian government to join the eurozone at any cost put a great burden on Latvian households after the crisis of 2008. Nevertheless, no popular protest movement emerged to change the course of this decision. This study discusses why Latvians undertook individual strategies to cope with the forex loan crisis. Particularly, I look at the choice between formal debt relief procedures and emigration as alternative individual strategies for defaulted debtors. These programmes have not reversed the negative migration trends or significantly decreased the number of Latvian households in arrears. Debt discharge is mainly attainable for wealthy individuals who are able to mobilise their financial and kinship resources. Worse-off debtors cannot attain debt discharge or are stigmatised during the process. Alternatively, emigration has offered a way to cope with overindebtedness and keep up with mortgages and consumer loan payments for a much larger segment of the debtor population.
The runoff coefficient (RC) is widely used despite requiring to know the effective contributing area, which cannot be known a priori. In a previous work, we defined runoff length (RL), which is difficult to measure. This work aimed to define the minimum RL (mRL), a quantitative and easy proxy of RL, for use in a pilot study on biocrusts in the Tabernas Desert, Spain. We show that RC decreases according to a hyperbola when the contributing area increases, the independent variable being the length of the effective contributing area and its coefficient involving the effects of rainfall and surface features and antecedent conditions. We defined the mRL as the length of the effective contributing area making RC = 1, which is calculated regardless of the area. We studied mRL from three biocrust types and 1411 events clustered in seven categories. The mRL increased with rain volume and intensity, catchment area and slope, whereas plant cover and biocrust succession (with one exception) had a negative effect. Depending on the plot, mRL reached up 3.3–4.0 m on cyanobacterial biocrust, 2.2–7.5 m on the most widespread lichens, and 1.0–1.5 m on late-successional lichens. We discuss the relationships of mRL with other runoff-related parameters.
This paper explores the responses to the housing crisis in Dublin, Ireland, by analysing recent housing policies promoted to prevent family homelessness. I argue that private rental market subsides have played an increasing role in the provision of social housing in Ireland. Instead of policies that facilitate the construction of affordable housing or the direct construction of social housing, current housing policies have addressed the social housing crisis by encouraging and relying excessively on the private market to deliver housing. The housing crisis has challenged governments to increase the social housing supply, but the implementation of a larger plan to deliver social housing has not been effective, as is evidenced by the rapid decline of both private and social housing supply and the increasing number of homeless people in Dublin.
We studied a population of the regionally endangered marsh fritillary butterfly Euphydryas aurinia inhabiting a system of loosely connected dry calcareous grasslands in sub-Mediterranean Slovenia. Our goal was to set the basis for a long-term monitoring of this butterfly in four meadows using mark-release-recapture (MRR). We determined its demographic parameters, dispersal, behaviour and utilization of nectar plants in different quality patches. Total population size was estimated to be approximately 347 males (95% confidence interval: 262-432) and 326 females (95% confidence interval: 250-402), with an unbiased sex ratio. The average lifespans were 6.3 and 8.6 days, respectively. Daily population sizes followed a parabola with marked protandry. Both sexes were relatively highly mobile with both occasionally moving over half a kilometre. The spatial distribution of animals seemed to be associated with patch size, host plant densities and nectar sources, resulting in much higher population densities in the largest patch. Adult behaviour differed between the sexes, with females resting more and flying less than males. Behaviour also changed during daytime and with the progression of the season. Adults were confirmed to be opportunistic feeders, since as many as ten nectar sources were detected. We conclude that demographic parameters differ greatly among regions and habitats, thus conservation aims should be planned accordingly. Although the population studied is apparently in good condition, there are threats that may hamper the long-term persistence of the species in this area: succession, intensification of mowing and overgrazing., Jure Jugovic, Costanza Uboni, Sara Zupan, Martina Lužnik., and Obsahuje bibliografii