ABSTRACT
Abstract The introduction of species is an important global threat to native ecosystems and yet little is known about invasion risks of non-native bees. Moreover, urbanization is increasing rapidly around the world with impact on the bee fauna. The city of Curitiba (Brazil) could be considered a model system for studies under this scope, with historical samplings and monitoring programs since the 1940s. This paper aims to quantify the current ecological impact of the non-native bee species present in Curitiba by using an integrative measure of impact and to define their current population status by classifying them into a unified framework for biological invasions. Ten sites were actively sampled in the metropolitan area of Curitiba during ten months. In addition to Apis mellifera Linnaeus, 1758, we found two others non-native species, Anthidium manicatum (Linnaeus, 1758) and Melipona scutellaris Latreille, 1811. None of them changed the native bee community structure, but they got different values of impact due to their ranges and abundances. While the honeybee is a known invasive species, A. manicatum was also considered invasive and has persisted in the city since the 1940s, interacting with the non-native plant Leonurus japonicus Houtt. M. scutellaris, a cultivated stingless bee species, had its first record for the city and fits the casual non-native category. We suggest monitoring the non-native bee species and actions centered on beekeepers to avoid future illegal introductions. The honey production or hobby interest on stingless bees can offer additional obstacles for species conservation when decoupled of scientific knowledge.
ABSTRACT
O caramujo gigante africano Achatina fulica é freqüentemente encontrado em ambientes antrópicos em diferentes municípios brasileiros, o que leva a considerar a possibilidade que seu estabelecimento esteja associado a ambientes alterados. Desta forma, objetivou-se diagnosticar o sítio de ocorrência e as características da população do caramujo invasor em um fragmento de Floresta Ombrófila Densa no município de Morretes, PR. Apesar do fragmento ser constituído por floresta secundária, foram encontradas poucas espécies de vegetação exótica, sendo o mesmo caracterizado por uma grande diversidade florística. Foram coletados 396 animais e registrados grandes espaçamentos entre os indivíduos. Os animais foram encontrados principalmente no solo e ativos no período da manhã, o que evidencia a expansão do horário de forrageamento. Os resultados sugerem que os animais presentes na mata nativa se constituem de uma população recente, resultante principalmente da saturação de áreas antrópicas, indicando a urgência de medidas para diminuição da população desses animais em área urbanas.
The giant African snail Achatina fulica is frequently found in antropic environments in different Brazilian municipal districts, which leads to consider the possibility that its establishment is associated to disturbed habitats. For this reason, the objective set in this paper is to diagnose the occurrence and the population characteristics of the invasive snail in an Atlantic forest fragment in the municipal district of Morretes of the State of Paraná. Although the fragment is a secondary forest, few species of non-native vegetation were found there, and the area is characterized by great floristic diversity. There were collected 396 snails and large spacing was registered between the animals. The animals were found in activity and mainly on the ground during the whole morning period, which provides evidence of expanded forage periods. Results suggest that the animals present in the native forest fragment constitute a recently arrived population, resultant mainly of the saturation of disturbed areas under human influence. This implies urgency for measures to control and decrease populations of giant African snails in urban areas as a way to avoid invasion of natural forests.