OpenLB
Open Library of Bioscience

Since its arrival in 2004, the non-native Harlequin ladybird (Coleoptera: Coccinellidae) has rapidly spread throughout Britain, and it is now the most common coccinellid in England. There have since been concerns about the detrimental effects it may have on native coccinellids because there is a strong correlation between the arrival of and the decline in native species, including the two-spot ladybird, . However, there have been few studies of the behavioural interactions between these two species, which occupy a high-niche overlap. This study investigated if the presence of impacts the feeding behaviour of through direct competition for aphid prey. Foraging and interactive behaviour of and were investigated within microcosms. exhibited a similar consumption rate and time in the presence of , yet consumed 3.5 times more prey items and were seven times faster compared to . Observations showed that does not directly disrupt the feeding behaviour of , but rather indirectly excludes the native species through being a superior competitor for prey items. Results indicate that the decline in native coccinellid species may be a consequence of competitive advantage, but that the concept of coexistence should not be dismissed.