Insect antenna as a smoke detector

The larvae of jewel beetles of the genus Melanophila (Buprestidae) can develop only in the wood of trees freshly killed by fire1. To arrange this, the beetles need to approach forest fires from as far as 50 kilometres away1, 2. They are the only buprestid beetles known to have paired thoracic pit organs3, which behavioural2, ultrastructural4 and physiological experiments5 have shown to be highly sensitive infrared receptors, useful for detecting forest fires. It has been suggested that Melanophila can sense the smoke from fires6, but behavioural experiments failed to show that crawling beetles approach smoke sources2. We find that the antennae of jewel beetles can detect substances emitted in smoke from burning wood.