Sex-specific life-history strategies among immature jumping spiders: Differences in body parameters and behavior.

Selection forces often generate sex-specific differences in various traits closely related to fitness. While in adult spiders (Araneae), sexes often differ in coloration, body size, antipredator, or foraging behavior, such sex-related differences are less pronounced among immatures. However, sex-specific life-history strategies may also be adaptive for immatures. Thus, we hypothesized that among spiders, immature individuals show different life-history strategies that are expressed as sex-specific differences in body parameters and behavioral features, and also in their relationships. We used immature individuals of a protandrous jumping spider, Carrhotus xanthogramma, and examined sex-related differences. The results showed that males have higher mass and larger prosoma than females. Males were more active and more risk tolerant than females. Male activity increased with time, and larger males tended to capture the prey faster than small ones, while females showed no such patterns. However, females reacted to the threatening abiotic stimuli more with the increasing number of test sessions. In both males and females, individuals with better body conditions tended to be more risk averse. Spiders showed no sex-specific differences in interindividual behavioral consistency and in intraindividual behavioral variation in the measured behavioral traits. Finally, we also found evidence for behavioral syndromes (i.e., correlation between different behaviors), where in males, only the activity correlated with the risk-taking behavior, but in females, all the measured behavioral traits were involved. The present study demonstrates that C. xanthogramma sexes follow different life-history strategies even before attaining maturity.

Beyond polyphagy and opportunism: natural prey of hunting spiders in the canopy of apple trees.

Spiders (Araneae) form abundant and diverse assemblages in agroecosystems such as fruit orchards, and thus might have an important role as natural enemies of orchard pests. Although spiders are polyphagous and opportunistic predators in general, limited information exists on their natural prey at both species and community levels. Thus, the aim of this study was to assess the natural prey (realized trophic niche) of arboreal hunting spiders, their role in trophic webs and their biological control potential with direct observation of predation events in apple orchards. Hunting spiders with prey in their chelicerae were collected in the canopy of apple trees in organic apple orchards in Hungary during the growing seasons between 2013 and 2019 and both spiders and their prey were identified and measured. Among others, the composition of the actual (captured by spiders) and the potential (available in the canopy) prey was compared, trophic niche and food web metrics were calculated, and some morphological, dimensional data of the spider-prey pairs were analyzed. Species-specific differences in prey composition or pest control ability were also discussed. By analyzing a total of 878 prey items captured by spiders, we concluded that arboreal hunting spiders forage selectively and consume a large number of apple pests; however, spiders' beneficial effects are greatly reduced by their high levels of intraguild predation and by a propensity to switch from pests to alternative prey. In this study, arboreal hunting spiders showed negative selectivity for pests, no selectivity for natural enemies and positive selectivity for neutral species. In the trophic web, the dominant hunting spider taxa/groups (Carrhotus xanthogramma, Philodromus cespitum, Clubiona spp., Ebrechtella tricuspidata, Xysticus spp. and 'Other salticids') exhibit different levels of predation on different prey groups and the trophic web's structure changes depending on the time of year. Hunting spiders show a high functional redundancy in their predation, but contrary to their polyphagous nature, the examined spider taxa showed differences in their natural diet, exhibited a certain degree of prey specialization and selected prey by size and taxonomic identity. Guilds (such as stalkers, ambushers and foliage runners) did not consistently predict either prey composition or predation selectivity of arboreal hunting spider species. From the economic standpoint, Ph. cespitum and Clubiona spp. were found to be the most effective natural enemies of apple pests, especially of aphids. Finally, the trophic niche width of C. xanthogramma and Ph. cespitum increased during ontogeny, resulting in a shift in their predation. These results demonstrate how specific generalist predators can differ from each other in aspects of their predation ecology even within a relatively narrow taxonomic group.

Are there real unprovoked/unprecipitated seizures?

Resistant epileptic patients often experience seizure precipitating conditions. Their lack or presence is extremely important not only for the diagnosis of epilepsy but also for the most appropriate treatment of the seizures. Unfortunately, there are a lot of uncertainty in their evaluation occurring in the daily routine and the exact definitions for the practice are still lacking. Based on the consonant and contradictory aspects concerning the consideration of the seizure precipitant factors a new hypothesis is suggested: every clinical epileptic manifestation should need a tonic (chronic cerebral cortical epileptic dysfunction) and a phasic (acute epileptogenic noxa) condition simultaneously. Results of a pilot study aimed to evaluate the possible role of precipitants in the manifestation of habitual seizures of patients strengthened the hypothesis. The (34%) total population might be more sensitive to actual phasic epileptogenic changes and 5.5% who are considered as "seizure precipitant responders". The five most frequent precipitants provoked the patients' "habitual" seizures were: unexpected life events (29.6%), changes in drug intake (23.7%), insomnia (20%), meteoropathological effects (17%) and alcohol consumption (9.5%). The paper lists the evidences and practical experiences supporting the hypothesis and mentions some counter arguments. In conclusion, the acceptance of the hypothesis might open new perspectives in the complex antiepileptic therapy especially for the subpopulation most vulnerable of phasic epileptogenic conditions (about 5-6% of the total). Further investigations are recommended to elucidate the remaining theoretical and practical reservations.

Car drivers with epilepsy (Pilot Hungarian EPIMED Database Evaluation).

We investigated aspects of driving among Hungarian patients with epilepsy. Nineteen percent (148/753) of our population had a driving license (DL), including 26% (38/148) who used it. Among persons without a DL, 29% (178/605) desired one. Among those who drove (n=38), 24 worked and 8 had experienced seizures in the last 3 months. Each of these seizures occurred during sleep (5/8), were preceded by known auras and warning signs (2/8) or were provoked by extreme external factors (1/8).