The Four-spotted Chaser (Libellula quadrimaculata) is one of the commonest Irish dragonflies. The flight period extends from mid May to the end of August. It is particularly common on sheltered lowland lakes and ponds. It can also be found on acid bogs breeding in very small pools and on sheltered upland lakes. Adults are aggressive and very territorial. This species may be confused with females and immature males of the Broad-bodied Chaser Libellula depressa and the Black-tailed Skimmer Orthetrum cancellatum, however in the latter two species there is no dark spot on the middle of the leading edge of the wings.