A cosmopolitan dragonfly, the four-spotted skimmer (Libellula quadrimaculata) is found throughout much of North America, Europe and Asia. Four-spotted chaser is another common name for this medium-sized dragonfly with a stout body. A strong flier, the four-spotted skimmer can be seen perching horizontally on vegetation near still water – marshes, ponds, lakes and slow streams.
The four-spotted skimmer’s abdomen is olive to orange-brown, getting darker toward the end of the abdomen. There are yellow markings on the abdomen sides. The thorax is somewhat hairy. The four-spotted skimmer’s leading wing edges are orangish with two small dark spots on each wing. The spot at the nodus (slight bend in the wing at the midpoint of the front edge) is smaller than the stigma spot (near the tip of the wing). A large dark area is at the base of the hind wings. ( I am not certain where the “four-spotted” comes from as I count more than four spots – perhaps it refers to the number of spots on the leading edge of each wing pair?) Female four-spotted skimmers are paler than males but have the same markings.
A four-spotted skimmer has a life cycle of two years. In the summer mating takes place in the air. The female lays her eggs on floating vegetation or on the surface of the water above submerged vegetation. The male sometimes guards the female while she oviposits. After about a month the eggs hatch. For two years the larvae (nymphs) grow in the water. When mature the nymph leaves the water, usually in the early morning, sheds its skin and emerges as a winged adult. The adult only lives for a few weeks during which time it matures sexually, mates and begins the cycle anew.
Adult four-spotted skimmers are voracious eaters consuming mosquitoes, gnats, midges and even other smaller dragonflies. The nymphs feed on other insect larvae.
These four-spotted skimmers were photographed at Reflection Lake in Lassen National Volcanic Park (CA).