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Population studies of tropical butterflies are still scarce considering the huge diversity of species worldwide, and historical data are even more limited.The present paper describes in detail the population parameters of M. cymo salonina from a semideciduous forest in the interior of São Paulo state, Brazil. A mark-release-recapture (MRR) program was carried out in a forest fragment in Sumaré municipality, from August 17, 1974 to October 26, 1977. In total, 2892 individuals were captured and marked (1620 males and 1272 females). The estimated population size varied from two to 1349 individuals per day for males and from one to 908 for females. For both sexes, the population showed a markedly seasonal pattern in the three studied years, with a distinct peak at the end of the wet season, followed by a decrease in numbers at the beginning of the dry season, maintaining low numbers until the mid-wet season. The overall sex ratio (56% male) was male-biased, but considering the months separately, this bias was reported in only nine out of the 25 tested months. The residence time (based on recaptured individuals) varied from one to 91 days for males and from one to 112 for females; the average residence time of males and females was not significantly different. The age structure was unstable and showed a clear predominance of new individuals at the onset of the population peaks, followed by an increase in the proportion of intermediate and old individuals in the ensuing months. Survival curves were similar for both sexes, approaching a type II survival curve. The present study provides novel information regarding this group, indicating that general patterns are still not well explored. Therefore, any further studies on ithomiines, including different species and populations of already studied species, are highly encouraged. [ABSTRACT FROM AUTHOR]

In the social behaviour of arthropods, regurgitation (feeding of the young) is a component of maternal care. In this paper, we describe regurgitation under laboratory conditions in species that share the same habitat, one subsocial (Anelosimus baeza) and a species considered to be solitary (Anelosimus nigrescens). The recently emerged spiderlings were fed by five of the nine A. baeza and six of the eight A. nigrescens females. In both species, the mother is critical in the initial stages, as spiderlings cannot feed themselves until the second instar. Our data suggest that A. nigrescens may be a subsocial species; this is the first report of regurgitation in these species. This fact shows the importance of regurgitation contributing to cooperation in live spiders. Future studies on maternal behaviour in these species are needed to elucidate the degree of sociality. [ABSTRACT FROM AUTHOR]

Some wasp species use spiders as food resources, overcoming several anti-predator barriers that are exerted by spiders. Tromatobia ichneumonid wasps are spider egg predators that usually attack Araneidae species, although there are few records of predation on Clubionidae, Philodromidae, Linyphiidae, Tetragnathidae, and Theridiidae spiders. Here, we describe the interaction between Tromatobia sp. and Chrysso compressa, a subsocial theridiid spider that exhibits extended maternal care, in the Atlantic Forest of southeastern Brazil. We observed that the larva of Tromatobia sp. develop inside the egg sacs of C. compressa, preying on the entire egg mass and building cocoons that change the color and morphology of the egg sacs. Despite these structural modifications, we registered an adult female of C. compressa guarding and caring for the cocoons (attacked egg sac) of the predators as if they were offspring (non-attacked egg sac). To the best of our knowledge, this study represents the first record of Tromatobia preying on Chrysso eggs. [ABSTRACT FROM AUTHOR]

Understanding high biodiverse areas and interactions among organisms requires reciprocal action between scientists and community through citizen science. This paper results from the joint efforts of an amateur nature photographer and scientists to describe the predation behaviour of the heron Ardea cocoi upon the lizard Ameiva ameiva. We also discuss the importance of citizen science and digital photography for natural history studies. [ABSTRACT FROM AUTHOR]

Deinopid spiders use highly specialized webs composed of a triangular non-sticky scaffolding (NS scaffolding) containing three radii and a modified orbicular web with a rectangular shape to capture prey. Spiders actively manipulate their webs to capture prey. We describe the web construction behavior of Deinopis cf. cylindracea and compare it and the shape of the sticky silk spiral (SS spiral) of other deinopid species using images in the literature and on the Internet. The web-building behavior in D. cf. cylindracea follows the pattern previously described for other species of Deinopis MacLeay, 1839. Web construction takes approximately 15 min in D. cf. cylindracea and has two stages: NS scaffolding construction and SS spiral construction. The final structure of the SS spiral has four closely spaced capture cords, five placed further apart, three near the top of the web, and two cords on the handles, making a total of 12. Other species of Deinopis have different numbers of cords. Finally, a novel finding is that the youngest spiders do not make webs with sticky lines, but instead use a simplified web to lunge forward, using only their legs to contact prey. To our knowledge, such behavior has never been described in this or any other group. [ABSTRACT FROM AUTHOR]