Table 3 - uploaded by Thomas Persson Vinnersten
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Citations
... Aquatic hemipterans, or water bugs, form a large group of adapted species that colonize temporary wetlands (Wiggins et al., 1980;Heckman, 2011). Like most hemipterans they live in permanent water bodies during winter, colonizing temporary ponds and wetlands at the approach of sexual maturity in springtime, during dispersal flights (Wiggins et al., 1980;Persson Vinnersten, 2007). After mating, the new generation needs to develop quickly before the wetlands dry up, when they fly once again to permanent water bodies. ...
... Because the water bugs reproduce later than P. thaul, it would seem that this insect requires wetlands to reach warm temperatures before they breed, since temperature has a direct impact on the development of their eggs (Jara & Perotti, 2018). Starting their development later than their prey could also be an adaptive strategy for water bugs and other aquatic predatory insects, since their newly hatched nymphs need to find abundant prey for survival (Persson Vinnersten, 2007). Moreover, differences between wetlands in water bug colonization dates could respond to different patterns of dispersion of adult populations. ...
Phenology has an important effect on the life strategies of species that live in temporary waters. Predaceous aquatic insects are key components of communities associated with seasonal ponds. Since the life cycles of these predators and their prey are unusual in that they occur at different moments of the pond hydroperiod, differences in temporal overlap could change the strength of their interactions. This study analyzed the phenology of the giant water bug Belostoma bifoveolatum and its prey. Breeding phenology, nymph population and prey phenology were studied extensively in three wetlands during the spring season. Experimental trials were carried out to evaluate prey consumption and prey preference. The results showed a strong overlap in phenology between the water bug and the Pleurodema thaul frog. The timing of tadpole and water bug nymph hatching could ensure high survival levels of the early immature stages of this insect. As giant water bugs develop, their prey selectivity experiences a shift, older nymphs and adults having a higher impact on tadpoles. The fluctuating climate of the Patagonian region probably influences the phenology of predator-prey assemblages in seasonal communities, and may have the potential to drive feeding performance and the strength of interspecific interactions.
Anurans have diverse reproductive modes, and some species of the austral forests of Patagonia have become specialized in terrestrial reproduction. Batrachyla taeniata is one of these species: it inhabits wetlands, lays its eggs during late summer and fall in terrestrial conditions, and has overwintering tadpoles. We studied a population of B. taeniata that breeds in wet meadows surrounded by native Patagonian forest, and described its life cycle parameters (breeding phenology, egg development and coexistence with other anurans) over two different years with contrasting hydroperiods. We also analyzed the effect of predatory insects on tadpole survival. Embryo development occurred in wet soil, which may be exposed to the sun or not, and took from 48 to 63 days to hatch. Free-swimming larvae overwintered in the wetland and coexisted in spring with pond-breeding anurans that varied in composition and abundance according to the wetland hydroperiod. The survivorship of B. taeniata tadpoles was significantly greater than that of P. thaul tadpoles when both were exposed to a free belostomatid predator. We consider that the terrestrial reproductive mode and life cycle of B. taeniata enable this species to survive in the variable biotic conditions determined by hydroperiod length.
Accepted manuscript
