Citronella primarily repels mosquitoes, as it interferes with their ability to locate and bite humans or animals by masking attractant odors and disrupting their sensory receptors. It is also somewhat effective against flies, gnats, certain ants, and ticks, though its efficacy varies by species and concentration
. However, citronella is not effective at repelling bees, wasps, cockroaches, or some biting insects like sandflies and blackflies
. Citronella works by emitting a strong, citrusy scent that is pleasant to humans but repels many insects. The essential oil contains compounds such as citronellal and geraniol that disrupt insects' ability to detect carbon dioxide and other signals that lead them to hosts, causing confusion and irritation to the insects
. While citronella is widely used in candles, sprays, lotions, and other products, its effectiveness can be limited. For example, citronella candles do not provide significant protection against mosquitoes compared to EPA-approved repellents like DEET
. The natural citronella plant itself contains citronellal but usually in concentrations too low to repel mosquitoes effectively on its own
. In summary, citronella is best known for repelling mosquitoes and to a lesser extent some other flying insects, but it is not a universal insect repellent and works best as part of a broader insect control strategy
