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A structural/cross-sectional micro-analytic perspective prevails in the Socio-constructivist research of peer knowledge construction. This paper proposes an alternative micro-sequential approach that focuses on the transitions between events during the activity. From this micro-sequential perspective, the study aimed to (a) explore the socio-cognitive interaction of symmetrical dyads of sixth and seventh graders solving a table comprehension task; (b) compare this interaction between symmetrical dyads of basic and advanced levels of competence. Participants were 148 sixth and seventh graders (74 dyads) from public schools in Rosario and nearby areas (Argentina). The dyads were symmetrical because their integrants had similar specific levels of competence (comprehension of a frequencies table) but differed in basic and advanced compositions. The interaction was coded using a system of mutually exclusive and exhaustive categories. An analysis of transition probabilities was performed among all codes, to identify activated/inhibited and inter-subjective/intra-subjective sequences. Transitions between statements aimed at solving the task formed the core of interactivity, as they comprise the codes that play a greater role in the elaboration of the task (shared by both symmetrical conditions). However, only the basic symmetry dyads showed an activating effect of the social feedback units. Transitions between cognitive questions and statements were also registered. Opinion questions were the most activated (inter-subjective) compared to demonstration and evaluation questions. Although these transitions were inter-subjective, they also differed according to the condition of symmetry. The work allows drawing conclusions about the relevance of a micro-sequential approach to interaction, since these results could not have been constructed from a classical structural perspective.

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In the search for insects as biological control agents for the water primrose, the delphacid Pissonotus paraguayensis (Delphacidae) was found on Ludwigia grandiflora subsp. hexapetala (Onagraceae) in a wetland of Central East Argentina. The morphology of the unknown females (brachypterous and macropterous) and immature stages are described and illustrated. Adults and nymphs were collected in wetlands of Del Plata River Basin, from Buenos Aires to the northeastern part of Argentina. A rearing methodology was developed to perform biological studies. Both winged forms and structural features of the female genitalia are described for the first time at the genus level. Eggs and immature stages are described and keyed; fifth nymphal instars may be easily recognised by the yellowish colouration, blackish on dorsal of head, thorax and abdomen with conspicuous yellowish pits, ventrally only darkened on base of frons extended to lower level of eyes and dorsal surface of antennomeres I and II, and legs with distinctive black marks at femoro-tibial joint and apex. The geographical distribution is updated, expanding its range into Argentina, making Buenos Aires the southernmost limit of the genus in America. Biological information of the species is also reported here: life cycle, fecundity, oviposition behaviour, and host plant. Field observations showed that P. paraguayensis breeds, feeds, and causes damage to L. g. subsp. hexapetala. This delphacid presents a certain degree of specificity to the Ludwigia species in the Jussiaea section in host specificity tests. More studies are required to test this species as a potential biological control agent. [ABSTRACT FROM AUTHOR]

In the first half of the twentieth century, the South American Locust (SAL), Schistocerca cancellata (Serville, 1838), was a major pest of agriculture in Argentina, Bolivia, Paraguay, Uruguay, and Brazil. From 1954–2014, a preventive management program appeared to limit SAL populations, with only small- to moderate-scale treatments required, limited to outbreak areas in northwest Argentina. However, the lack of major locust outbreaks led to a gradual reduction in resources, and in 2015, the sudden appearance of swarms marked the beginning of a substantial upsurge, with many swarms reported initially in Argentina in 2015, followed by expansion into neighboring countries over the next few years. The upsurge required a rapid allocation of resources for management of SAL and a detailed examination of the improvements needed for the successful management of this species. This paper provides a review of SAL biology, management history, and perspectives on navigating a plague period after a 60-year recession. [ABSTRACT FROM AUTHOR]

The Chilean water penny genus Tychepsephus Waterhouse, 1876 is revised, with descriptions and photographic illustrations of life stages including two larval morphotypes, the pupa of one morphotype, and adults of two species. The pupa of Tychepsephus has not been reported previously. Tychepsephus cekalovici sp. nov. is described, and Ectopria (Chilectopria) grandis Pic, 1947, syn. nov. is proposed as a new synonym of Tychepsephus felix Waterhouse, 1876, which is redescribed. Taxonomic treatment of the adults of both species includes images of the habitus of males and females, morphological variation, and male and female genitalia. Males and females are sexually dimorphic. Information on the habitat of Tychepsephus is provided and illustrated with photographs, and the known geographic distribution of the two species is mapped. The occurrence of Tychepsephus in Argentina is reported; therefore, the genus no longer can be considered endemic to Chile. The taxonomic status and geographic distribution in South America of other species of Psephenidae, particularly members of the subfamily Eubriinae, is reviewed. [ABSTRACT FROM AUTHOR]

Background: The huillín (Lontra provocax, Thomas 1908) is an otter, endemic to southern Argentina and Chile. It is in danger of extinction. In the Nahuel Huapi National Park and surroundings is the only freshwater, known and stable population of huillín in Argentina. In this park, several urban and rural centers coexist with this species. The main objective of our work was to answer: How does the local zoological knowledge (LZK) vary about the huillín, particularly its identification and sighting, among people from different social groups, with different ages and gender, who live in the rural or urban environment and with different periods of permanence in the place? Methods: Ninety-six written interviews were conducted using visual stimuli to ensure that interviewees refer to the huillín. In addition, we also inquire about the LZK of other species with which it can be confused. Additional open interviews were conducted with participants who observed the huillín to determine the georeferencing of the reported sites and include them on a final map. Results: 95% of people identified the huillín and this was confused with the coipo in 3% and with the american mink, in 5%. The results show that, in general, the LZK did not vary significantly with the sociocultural characteristics of the participants, showing a remarkable homogeneity. However, people in rural areas are more likely to observe the species than people in urban areas. Moreover, people between 20 and 40 years of age are more likely to observe the huillín. The LZK mapping has identified areas that are consistent with and/or adjacent to official source records. Other areas have also been identified that may provide new information. Conclusion: With this participatory work, we realize that the species is recognized by urban and rural inhabitants and very few confused it. The homogeneity in the LZK found constitutes a kick for the realization of other participatory studies that promote lines of research, action and management that improve the quality of the environments where the only freshwater, known and stable population of the huillín in Argentina lives. [ABSTRACT FROM AUTHOR]