Canadian Forest Service Publications
Impact de la température et de la durée d'exposition au froid sur la survie des adultes de la coccinelle asiatique, Harmonia axyridis (Pallas). 2003. Berthiaume, R.; Hébert, C.; Bauce, E. Phytoprotection 84 : 85-91.
Available from: Laurentian Forestry Centre
Catalog ID: 24486
The Asian ladybird beetle, Harmonia axyridis, an introduced species that is established in Quebec since 1994, rapidly became an entomological problem because it aggregates in buildings during fall and winter. The reason most often invoked to explain this behaviour is a weak resistance of the species to winter coldness. To determine cold resistance of the Asian ladybird beetle, a study including various cold temperatures and exposure times was carried out. Groups of 50 beetles were placed in Petri dishes and exposed to different temperatures (5, 0, -5, -10 and –20°C) for different periods of time (2, 6, 12 and 18 weeks). Results indicate that survival is strongly influenced by temperature but also by exposure duration. Furthermore, no Asian ladybird beetle survived at –20°C, even for only one day of exposure.