Nesting behavior of Trypoxylon (Trypargilum) agamemnom Richards (Hymenoptera: Crabronidae)

Nesting behaviour is extremely diversified among solitary nesting sphecids. Thus, the aim of this study was to describe the nesting behaviour of Trypoxylon agamemnon and discuss the advantages of guarding behaviour of males. It was conducted in the Parque Municipal das Araucárias, Guarapuava (PR), Brazil from October/2003 to July/2007. To describe the behaviour of T. agamemnon and construct its ethogram, daily observations were made, totalling 410:19 hours observation. Although the males of T. agamemnon stand guard close to the entrance of the nests, we concluded that this behaviour is not ensuring the protection of nests against parasitoids and that, probably, this behaviour ensures them the paternity, but further studies with microsatellite markers will be necessary to confirm this hypothesis

Nesting behavior of Trypoxylon (Trypargilum) agamemnom Richards (Hymenoptera: Crabronidae)

Nesting behaviour is extremely diversified among solitary nesting sphecids. Thus, the aim of this study was to describe the nesting behaviour of Trypoxylon agamemnon and discuss the advantages of guarding behaviour of males. It was conducted in the Parque Municipal das Araucárias, Guarapuava (PR), Brazil from October/2003 to July/2007. To describe the behaviour of T. agamemnon and construct its ethogram, daily observations were made, totalling 410:19 hours observation. Although the males of T. agamemnon stand guard close to the entrance of the nests, we concluded that this behaviour is not ensuring the protection of nests against parasitoids and that, probably, this behaviour ensures them the paternity, but further studies with microsatellite markers will be necessary to confirm this hypothesis

Arbuscular Mycorrhizal Fungal Networks Vary throughout the Growing Season and between Successional Stages

To date, few analyses of mutualistic networks have investigated successional or seasonal dynamics. Combining interaction data from multiple time points likely creates an inaccurate picture of the structure of networks (because these networks are aggregated across time), which may negatively influence their application in ecosystem assessments and conservation. Using a replicated bipartite mutualistic network of arbuscular mycorrhizal (AM) fungal-plant associations, detected using large sample numbers of plants and AM fungi identified through molecular techniques, we test whether the properties of the network are temporally dynamic either between different successional stages or within the growing season. These questions have never been directly tested in the AM fungal-plant mutualism or the vast majority of other mutualisms. We demonstrate the following results: First, our examination of two different successional stages (young and old forest) demonstrated that succession increases the proportion of specialists within the community and decreases the number of interactions. Second, AM fungal-plant mutualism structure changed throughout the growing season as the number of links between partners increased. Third, we observed shifts in associations between AM fungal and plant species throughout the growing season, potentially reflecting changes in biotic and abiotic conditions. Thus, this analysis opens up two entirely new areas of research: 1) identifying what influences changes in plant-AM fungal associations in these networks, and 2) what aspects of temporal variation and succession are of general importance in structuring bipartite networks and plant-AM fungal communities