Key life stages of two predatory ladybird species (Coleoptera : Coccinellidae)

Development and survival of larvae of two predatory ladybird species, Harmo nia axyridis (Pallas) and Coccinella septempunctata L. on hibiscus (Hibiscu s syridis L.) trees was followed daily outdoors during four seasons. Data w ere analysed and stage-specific mortality in a stage-structured model was e stimated using Manly's (1997) method. Subsequently, key factor analysis was used to determine the life stages in which the daily mortality was best co rrelated with the total mortality during larval life. Consistently with the results from the first two years, the larvae suffered the greatest mortali ty during the first and fourth instars The k-values for these two instars w ere also best correlated with those for the whole larval life, especially i n H, axyridis.