Common Green Darner
Anax junius
A pair of green darners, male in front at left, find an algae-covered pool the perfect place to leave their eggs. Salt River, Maricopa County, Arizona, USA. October 2009.
Aeshnidae -- Darner Dragonfly Family
From Wikipedia: The Green Darner or Common Green Darner, after its resemblance to a darning-needle, is a species of dragonfly in the family Aeshnidae. One of the most common and abundant species throughout North America and its range south to Panama. It is well known for its great migration distance from the northern United States south into Texas and Mexico. The Green Darner is one of the largest dragonflies existent: males grow to 76 mm (3.0 in) in length with a wingspan of up to 80 mm (3.1 in). Females oviposit in aquatic vegetation, eggs laid beneath the water surface. Nymphs (naiads) are aquatic carnivores, feeding on insects, tadpoles and small fish. Adult darners catch insects on the wing, including ant royalty, moths, mosquitoes and flies.