A New Light Trap Model as an Alternative for Controlling Pests in Eucalyptus Plantations

Eucalyptus plantations can be affected by species of defoliating caterpillars. The integrated management of this group primarily involves a monitoring system, natural enemies, and biological products. Alternative control methods, including the use of conventional light traps, have not been adopted, mostly because of their low efficiency. Therefore, a more efficient light trap model was developed. The new model allowed the capture of 3.6 times as many insects as the conventional model, with a 261% gain in control efficiency. The use of this new model represents another integrated management alternative for lepidopteran pests of eucalyptus plantations and other cultured plants.     

Growth dynamic of Leptospira spp. from Sejroe serogroup in different media formulae

The culturing of Leptospira strains from bovine clinical samples is challenging and has resulted in some gaps in securing an epidemiological understanding. Strains related to chronic reproductive leptospirosis in cattle belong to the Sejroe serogroup – not only Hardjoprajitno and Hardjobovis but also Guaricura genotypes. This study analyses the growth of Leptospira strains from serogroup Sejroe in different culture media, with the aim of suggesting better culturing approaches. To meet this objective, two culture media were applied: EMJH and T80/40/LH. In addition, three different cocktails of selective agents were chosen. The combinations of medium and selective additives resulted in 10 different tested formulae. The poor performance of Hardjobovis in EMJH indicated that its growth may represent a possible bias when culturing these strains from bovine samples. The most efficient medium for culturing Hardjobovis was T80/40/LH, while T80/40/LH medium + STAFF combination proved to be the best choice for growth, being recommended for obtaining a higher number of these strains from bovines.     

Predator abundance in relation to small game management in southern Portugal: conservation implications

The interaction between hunting interests and legally protected predators is often a contentious conservation problem, requiring detailed understanding of predator responses to game management. This issue was addressed in southern Portugal in a treatment-control natural experiment, whereby the abundances of small game, corvids, birds of prey and carnivores were compared in 12 game estates (>500 ha) and 12 matching areas with similar sizes and land uses but no game management. European rabbits (Oryctolagus cuniculus), Iberian hares (Lepus granatensis) and, less so, red-legged partridges (Alectoris rufa) were far more numerous in game estates than elsewhere. Among legally controlled species, there were less Eurasian jays (Garrulus glandarius) but more red foxes (Vulpes vulpes) in game estates, though the latter were primary targets of predator culling. Fox abundance within game estates varied inversely with an index of management intensity (density of small game feeding sites) and increased along with hare abundance. As for protected species, only common kestrels (Falco tinnunculus) and genets (Genetta genetta) were fewer in game estates. The abundance of raptors within game estates varied inversely with gamekeeper density, whereas that of common buzzards (Buteo buteo) increased along with rabbit abundance. Overall, there was little evidence that game management reduced local predator abundances, except in the most intensively managed estates. Game estates provided concentrations of prey that was scarce elsewhere, which may have favoured increased abundances of some predators. Further investigations are needed to find out whether high prey densities may attract predators to game estates with increased mortality risk, which may thus become population sinks for protected species.     

Viability ofSalmonella species in natural waters

The viability of different species ofSalmonella in seawater was studied under controlled laboratory conditions. The negative influence of water self-purifying factors exerted on the survival of the microorganisms varied depending on the factor considered and also on the specie selected. Biotic and luminous factors were mainly responsible for the inactivation and disappearance ofSalmonella in the water solutions. The addition of 1% of sewage to filtered seawater and freshwater provoked a decrease in the number ofSalmonella populations tested in comparison with the solutions without sewage. On the other hand, an increase of sublethally injuredSalmonella cells with respect to exposure time was not observed. From the results obtained from T₉₀ inactivation experiments, it may be deduced that the main factor implicated in the disappearance ofSalmonella from the water mass is physical dilution.