Behavioral response of Harmonia axyridis towards their footprints according to their physiological state

Poster (2012, August)

In order to survive cold, the multicolored Asian ladybeetle, Harmonia axyridis (Pallas), aggregates inside dwellings during winter. It has been recently highlighted that overwintering H. axyridis ... [more ▼]

In order to survive cold, the multicolored Asian ladybeetle, Harmonia axyridis (Pallas), aggregates inside dwellings during winter. It has been recently highlighted that overwintering H. axyridis individuals lay an area marking while walking, which is used by conspecifics to locate aggregation sites. These footprints are made-up of hydrocarbons, comprising both saturated and unsaturated homologues. However, it has not been demonstrated whether this “following area marking” behavior is specific to the overwintering individuals. The work presented herein was oriented to the study of the chemical evolution of these footprints according to the physiological state of H. axyridis. Monthly GC-MS analyses revealed that the area marking contained a greater amount of di-unsaturated compounds when laid by overwintering ladybeetles, suggesting the great importance of these chemicals in the ladybeetles aggregation process. In the second instance, behavioral investigations conducted in a Y-shaped glass tube were performed to assess (1) the evolution of H. axyridis behavior towards their footprints and (2) whether this behavioral modification is due to an evolution of the ladybeetles sensitivity or rather to an evolution of the area marking attractiveness. The results revealed that only the overwintering individuals follow their area marking, and that this behavior is linked to the ladybeetle physiological state rather than to the chemical profile of the marking biomolecules. [less ▲]