Montana Field Guide

The Lance-tipped Darner is a member of the family Aeshnidae. Darners are among the largest and fastest-flying North American dragonflies, 2 1/4-4 3/4" (57-120 mm) long. These brilliant blue, green, or brown insects have large, clear wings spanning up to 5 7/8". Their compound eyes meet on top of the head. The female hovers above water usually attached or guarded by the male and, using a well-developed ovipositor for slicing into emergent plants, thrusts eggs one at a time in the stems. Preferred habitat includes open, shallow marshy ponds, including some that are temporary, as well as the edges of larger open lakes, bogs, and slow streams. Wetland systems: Western Emergent Marsh, Northern Rocky Mountain Wooded Vernal Pool and the Rocky Mountain Subalpine-Montane Fen, Great Plains Open Freshwater Depressional Wetland, Great Plains Prairie Pothole

Lance-tipped Darners inhabit open, shallow marshy ponds, including some that are temporary, as well as the edges of larger open lakes, bogs, and slow streams. Many of the ponds selected for breeding dry up during the year (Dunkle 2000, Paulson 2009). They hunt, often in swarms, over marshes and fields and tend to perch vertically on low vegetation and shrubs, but will also perch on trees and branches (Dunkle 2000, Paulson 2009).

Larvae feed on a wide variety of aquatic insects, such as mosquito larvae, other aquatic fly larvae, mayfly larvae, and freshwater shrimp. They will also eat very small fish and tadpoles.
Adult- The dragonfly will eat almost any soft-bodied flying insect including mosquitoes, flies, small moths, mayflies, and flying ants or termites.

Male Lance-tipped Darners are territorial and patrol small areas along the shoreline or through semi-open vegetation, but flight is slower with less hovering compared to the Canada Darner (Aeshna canadensis). Females oviposit slowly and selectively on the stems of cattails (Typha spp.) and sweetflag (Acorus americanus) often well above the surface of the water in areas that tend to dry out. (Dunkle 2000, Paulson 2009).

Drought is a significant threat to this species as it selects wetlands and ponds for breeding that dry up during the year. In drought years, many of these habitats will already be dried up and breeding locations become scarce.