New York Natural Heritage Program
Arrowhead Spiketail
Cordulegaster obliqua (Say, 1839)
Insects

Identifying Characteristics [-]
Adult spiketails are large, black or brown dragonflies with strongly contrasting, bold yellow stripes and spots on the thorax and abdomen, respectively. Their eyes are large, green or blue-green, and barely touch at a single point on the top of the head. The legs are short and the wings are clear. Adult females have the same coloration and pattern as males, but have thicker abdomens and a prominent ovipositor that extends beyond the abdomen. The arrowhead spiketail has a black thorax with two bright yellow dorsal stripes and two bright yellow lateral stripes. The abdomen is also black with a striking pattern of bright yellow spots on top. The spots on abdominal segments 4-8 have a unique and distinctive arrowhead shape. The eyes are green in the northern portion of the species range, but blue where the species occurs on the southeastern coastal plain. Adults are approximately 3.1 inches (7.9 cm) in length in the northern portion of the range, but slightly larger to the south (Dunkle 2000). The larvae are elongate, subcylindrical, lack spines, and are very hairy. The antennae are composed of seven slender segments. The labium is large and spoon shaped with large, jagged teeth on the forward margin. Body length is approximately 1.53-1.57 inches (39-40 mm) at maturity (Walker 1958), which is reached at three or four years.

Characters Most Useful for Identification [-]
Close examination of the abdominal pattern is necessary for positive identification.

Best Life Stage for Proper Identification [-]
Mature adults are the best life stage for the identification of all dragonflies. Larval identification requires the use of detailed taxonomic keys, can be very difficult, and can be very unreliable, especially in the case of larvae that are not yet mature. Larval identification is best done by people with a great deal of expertise in this area.

Behavior [-]
Adult males patrol seepage areas with herbaceous vegetation and small rivulets, typically flying at a height of 1-3 feet, mainly during the midday hours. Females hover over the shallow water and drive their abdomen into the substrate to lay their eggs. These dragonflies usually perch fairly close to the ground on weed stems or twigs along forest edges. They will fly in forest clearings to feed (Dunkle 2000, Nikula 2003).
Arrowhead Spiketail Images
click to enlarge
The Best Time to See
Dates for New York records have been previously listed as May to July 1 (Donnelly 1999), but most recent New York records are from mid June through mid July with July 11 as the latest record to date (New York Natural Heritage Program 2005). Flight dates for this species in Massachusetts are from early June through mid July (Nikula 2003), whereas flight dates in the western Great Lakes states extend from late May to early August. Dunkle (2000) gives a somewhat longer flight period of mid April to late August, but this range would be for the full range of the species and this species would certainly not be expected to be flying in April anywhere in New York. August flight dates for New York seem possible, especially if the species is found in some more northern counties.
J F M A M J J A S O N D
Present Reproducing
The time of year you would expect to find Arrowhead Spiketail present (blue shading) and reproducing (orange shading) in New York.
Similar Species
  • Illinois River Cruiser (Macromia illinoiensis)
    This river and lake species has a single lateral stripe on the side of the thorax as opposed to the two found in spiketails. In addition, males have a prominent yellow abdominal spot on the 7th segment only, and while females have abdominal spots on additional segments, they are not arrow shaped as in the arrowhead spiketail.
  • Twin-Spotted Spiketail (Cordulegaster maculata)
    Like the delta-spotted spiketail, the twin-spotted spiketail has paired abdominal spots as opposed to the single row of arrow shaped spots on the arrowhead spiketail.
  • Tiger Spiketail (Cordulegaster erronea)
    The tiger spiketail has yellow rings on the abdominal segments as opposed to spots.
  • Delta-Spotted Spiketail (Cordulegaster diastatops)
    The delta-spotted spiketail has paired abdominal spots as opposed to the single row of arrow shaped spots on the arrowhead spiketail.