4 research outputs found
Host plants, biology and distribution of Acraea terpsicore (Linnaeus, 1758) (Lepidoptera: Nymphalidae): a new butterfly for northern Australia with potential invasive status
The nymphalid butterfly Acraea terpsicore has recently become established in northern Australia where it is spreading rapidly. The immature stages are briefly described, illustrated and compared with those of A.andromacha (Fabricius, 1775) from Australia, and information on its larval food plant specificity, biology and distribution is presented. The species occurs in highly modified open areas, including suburban roadsides, disturbed grassland (i.e. cleared woodland that is regularly slashed or graded) and degraded savannah woodland where it breeds primarily on Hybanthus enneaspermus (L.) F.Muell. (Violaceae), a widespread native herb that is also used as a natural larval food plant in India, and to a lesser extent on Passiflora foetidaL. (Passifloraceae), an introduced vine also used as a food plant in Indo-China and Indonesia. Extensive laboratory larval feeding trials on Violaceae, Passifloraceae and Cucurbitaceae revealed limited ability of the Australian population to consume Passifloraceae and lack of ability to feed on Cucurbitaceae, indicating that A.terpsicore is unlikely to become a pest of vegetable and horticultural crops. It is hypothesised that the narrower host range in Australia is attributed to the founder effect of a limited gene pool. Within 14 months of colonisation, A.terpsicore has occupied much of the western half of the 'Top End' of the Northern Territory and spread to the eastern Kimberley of Western Australia, with an estimated extent of occurrence of 112000km2 and average dispersal rate of 315±56 (SE) km/year. Because the butterfly has the ability to exploit (injure) Violaceae, and potentially outcompete A.andromacha, it may qualify as an invasive species
Spatial distribution and range expansion of the Tawny Coster butterfly, Acraea terpsicore (Linnaeus, 1758) (Lepidoptera: Nymphalidae), in South-East Asia and Australia
Documenting the range size and range boundaries of species, and understanding the factors determining changes in these spatial components, is crucial given current rates of anthropogenic climate change and habitat loss. Here, we document the establishment of the acraeine butterfly, Acraea terpsicore, in South-East Asia (Indonesian islands south of Malay Peninsula, and Timor) and Australia for the first time. We estimate its rate of colonisation and potential for further range expansion in the Indo-Australian region according to bioclimatic niche models. We modelled the potential distribution of the species in the Indo-Australian region under current climatic conditions and in 2050 following climate change. The bioclimatic niche models were based on five different modelling techniques, three global circulation models (GCMs) and two CO2 emission scenarios (SRES), yielding 30 individual models that were combined in a consensus model. Acraea terpsicore became established in Indo-China (Thailand) during the 1980s and since that time it has spread to other parts of South-East Asia. It was first recorded on the Australian mainland in the Northern Territory in April 2012 and within a few months of detection was found to occur at six locations, with an estimated extent of occurrence of 4000 km2. Thus, the range size of A. terpsicore has expanded by approximately 6000 km across the equator (c. 32 degrees latitude) in 28 years, with an average rate of colonisation (from Thailand to Australia) of 200 km year-1 (range: 170-230 km year-1). The bioclimatic niche models identified additional regions with favourable climatic conditions, and within Australia it is likely to occupy coastal and subcoastal savannah woodlands of the entire monsoon tropics, indicating potential for further range expansion. Moreover, the species' potential range is likely to increase with climate change. We hypothesise that habitat modification, particularly rapid deforestation of tropical forest in South-East during the past three decades, is a major factor accounting for the range expansion given the species' habitat preference for disturbed and open degraded areas. Climate change may be a contributing factor but is unlikely the sole determinant given the spatial area involved and rate of spread