Distribuição potencial e impacto de mudanças climáticas sobre a praga de girassol Chlosyne lacinia (Lepidoptera: Nymphalidae)

• Autor(a) principal: Fortes, Juliana Chagas
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3888
• topic: Chlosyne lacinia; Mudanças climáticas; Modelagem de distribuição; Maxent; Mahalanobis; Chlosyne lacinia; Climate change; Distribution modeling; Maxent; Mahalanobis; CNPQ::CIENCIAS BIOLOGICAS::ECOLOGIA

The existence of global climate change caused by anthropogenic impacts and the importance of predicting its biological effects have revived the interest in understanding abundance and distribution determining factors. Several methods that allow the creation of climate based ecological niche models can be used to predict species potential distribution and the effects that climate change can have over distributional areas. Building such models can help the understanding on how climate can determine species distributions, as well as indicating pest infestation risk areas. Chlosyne lacinia caterpillars are a major sunflower (Helianthus annuus) pest on Brazil, and its attacks at 50 and 70 days old plants can reduce the productivity up to 80%. This work aimed at areas with suitable climate for the current and future potential occurrence of C. lacinia and its subspecies at the American continent, and for sunflower culture in Brazil. The models were created using Mahalanobis distance and Maximum Entropy (Maxent) methods, for C. lacinia and the subspecies C. l. adjutrix, C. l. crocale, C. l. lacinia and C. l. saundersii. According to AUC (area under the sensibility versus specificity curve) values, model performance were great, which explains the similarity of results from both methods. The results showed that it is possible that the whole species distribution may not be altered by climate changes, but the intra-specific variation will be largely affected. C. l. saundersii distribution is expected to shrink and be isolated, and C. l. adjutrix can loose all suitable areas. However, hese results can be affected by the gene flow between subspecies. The areas with suitable climates for sunflower culture in Brazil are expected descrease, although it is possible that genetic improvement efforts can surpass climatic limitations, allowing the occupancy of areas not predicted by the modeling, and avoiding the effect of the pest. Even though distribution modeling methods are seldom used for pest distribution predictions, its usage proved to be an interesting method for obtaining information about the species and the intra-specific variation.