The seasonal activity patterns of Scolopendra cingulata and S. cretica in relation to abiotic factors and microhabitat preferences in five eastern Mediterranean

The responses of gnaphosid spiders to an urbanization gradient (urban-suburban-rural areas) were studied using pitfall traps in and near the city of Heraklion, in Crete, Greece, from October 2010 to October 2011. Our results indicate that richness and abundance of species of spiders decreased from the rural area to the center of the city, but not significantly so. Temporal beta diversity was significantly higher in urban areas, which indicates a high temporal variability in species composition of gnaphosid assemblages in the center of the city that takes the form of complementary rather than synchronized phenologies of co-occurring species, as expected in habitats degraded by high levels of disturbance. There was no specific pattern in the body size distribution of the gnaphosids along the urban-rural gradient, and thus the decrease in mean body size with increase in urbanization hypothesis was not supported by our results. However, the species composition recorded in urban areas was very different from that in suburban and rural areas. The percentage of individuals in the catches that were generalist species differed significantly along the gradient. As generalist gnaphosid species made up 72.01% of the total caught in the center of the city, and only 9.53% and 2.07% in suburban and rural areas respectively, our results support the opportunistic species hypothesis. Our analyses indicate that Urozelotes rusticus, a well known synanthropic species recorded for the first time in Greece, is an indicator of high levels of urbanization in Heraklion.

The foraging activity of Mesobuthus gibbosus was studied and analysed over 290 field samplings in Koufonisi island (central Aegean) and Crete (south Aegean) during the period of maximal activity of the species. The results showed that on both islands males and juveniles searched for prey mainly relatively near or far from their burrows (“sit‐and‐wait” strategy), whereas females foraged comparatively more than males and juveniles at the entrances of their burrows (“doorkeeping” strategy). Throughout the study, there was no evidence of two or more individuals foraging together. Re‐emergence time after digestion lasts probably more than one month, because no individual was observed foraging twice in the 30 consecutive days of the study period. The individuals that followed the sit‐and‐wait strategy were larger in size compared to those of the same sex or age‐class that used the doorkeeping strategy. The diet of the species was wide, including representatives of eight arthropod orders on Koufonisi and seven on Crete. Stinging was selective and prey selection was based on the age‐class of the predator and the size of the prey compared to the size of the predator. The success of sit‐and‐wait foraging individuals was much more dependent on abiotic factors compared to scorpions using the doorkeeping strategy. Moon phase, air and soil temperature and air relative humidity were the abiotic factors which mainly influenced the foraging activity of these generally non‐cannibalistic opportunistic ambush predators on both islands.

This study explores the locomotory activity of Mesobuthus gibbosus on Koufonisi Island (central Aegean). We measured orientation of movement, shelter selection and abiotic factors that influence locomotive activity throughout the circadian and lunar cycles. Our results show M. gibbosus is a highly active and negatively phototactic species with sexually dimorphic patterns of movements that are related to maternal protective behaviour. Male scorpions disperse more widely, apparently as a function of mate search, and exhibit much more opportunistic locomotive behaviour. The locomotory activity of the population was influenced by moon phase (negative phototropic) and air temperature, did not differ intersexually, and was directed towards a dry stone-wall where shelter was readily available.