Diet

• Dythemis nigrescens is a predatory dragonfly. Adults capture small flying insects, including flies, mosquitoes and other small insects, usually from perches along streams and other open freshwater habitats.

• The aquatic larvae are predators of mosquito larvae and other aquatic invertebrates.

Range

• The Black Setwing is primarily a Mexican species, ranging from Arizona and Oklahoma south through Mexico to Oaxaca, including much of the Pacific slope.

Habitat

• Dythemis nigrescens is particularly associated with streams, small rivers and quebradas with moderate current, often in relatively dry tropical landscapes.

• It is also characteristic of tropical dry forest. A specimen from Sonora was collected in tropical deciduous forest, while populations in Jalisco occur in tropical dry forest.

• Around Zihuatanejo, suitable habitat includes stream margins, rocky or sandy creek beds, seasonal waterways and clearings within tropical dry forest. Adults often perch conspicuously on low vegetation beside the water.

Description

• Dythemis nigrescens is a medium-sized skimmer with the characteristic “setwing” posture: it commonly perches with the wings angled downward and the abdomen raised above the rest of the body.

• Mature males become predominantly dark to black, giving rise to the common name Black Setwing. The upper frons has a metallic purplish colour, while the thorax has diffuse pale markings forming characteristic patterns on the sides.

• The male abdomen is relatively slender and has contrasting pale markings along the sides of abdominal segments 4–7. Females and immature males are generally browner and less uniformly dark.