Is there a link between air pollution and a drop in global insect numbers?

A study has found that an insect’s ability to find food and a mate is reduced when its antennae are contaminated by particulate matter from industry, transport, bushfires, and other sources of air pollution (Nature Communications). Using a scanning electron microscope, the researchers found that as air pollution increases, more particulate material collects on the sensitive antennae of houseflies. This material comprises solid particles or liquid droplets suspended in air and can include toxic heavy metals and organic substances from coal, oil, petrol, or woodfires. They exposed houseflies for just 12 hours to varying levels of air pollution in Beijing and then placed the flies in a Y-shaped tube ‘maze’. Uncontaminated flies typically chose the arm of the Y-maze leading to a smell of food or sex pheromones, while contaminated flies selected an arm at random, with 50:50 probability. Neural tests confirmed that antenna contamination significantly reduced the strength of odour-related electrical signals sent to the flies’ brains — it compromised their capacity to detect odours, says a release.