Role of long-chain hydrocarbons in the aggregation behaviour of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae)

► The use of non-volatile compounds by H. axyridis during aggregation was investigated. ► Two different chemical blends were collected in and around aggregation sites. ► These blends are made up of saturated and unsaturated hydrocarbons. ► The first one leads congeners towards aggregation. ► The second one ensures the cohesion of the cluster.