Body size and food plants drive local extinction risk in butterflies

Lepidoptera, butterflies and moths, are significant pollinators and ecosystem health indicators. Therefore, monitoring their diversity, distribution, and extinction risks are of critical importance. We aim to understand the drivers of the local extinction risks of the butterflies in Bangladesh. We conducted a systematic review to extract the diversity, distribution and local extinction risks of the butterflies of Bangladesh, and possible drivers of their extinction, e.g., body size, host plants and nectar plants. We updated the current checklist, which now consists of 463 species. We provided distribution and extinctions risk atlas showing both the diversity and extinction risks were highest in the eastern region of Bangladesh. We tested whether body size and host plants contribute to the local extinction risks of butterflies. We predicted butterflies with larger body size and fewer host plants and nectar plants would be in greater extinction risk. Accordingly, we showed that extinction risk was higher in larger butterflies than smaller butterflies, and in butterflies with a fewer number of host plants and nectar plants than the butterflies with higher number host plants. Our study highlights the contribution of body size and host plants as potential drivers of the local extinction risks of butterflies.