Explanation of Names
Common name "spiketail" comes from the females large spike (modified genital plate used as an ovipositor). (2)
9 spp. of a single genus in our area(3)
Very large slender dark dragonflies with striking yellow markings on the abdomen and yellow stripes on the sides of thorax.
Eyes almost or just barely meet in a small section.
Females are easily identified by her large spike extending beyond the tip of the abdomen.
Females use this spike as an ovipositor, stabbing it into the sediment where she deposits her eggs. Males do not have a "spike".
Will perch hanging vertically (or at a slight angle) from branches or vegetation. Males will actively patrol low over the water, up and down the length of their chosen stream.(2)
Spiketail larvae can be distinguished by their irregular jagged teeth:
almost entirely Holarctic (+adjacent montane parts of the Oriental Region); in our area, markedly more diverse in se. US(1)
Most are associated with small to mid-sized cold clear streams, often forested. Larva are burrowers.(2)
June into early July in Ontario.
Rarely encountered due to their specific habitat requirements and habit of rarely perching, or not perching for long, and a fairly short flight period. Best chances of encountering spiketails is at their small stream habitat where you can watch for males patrolling up and down the length of the stream. They are fast strong flyers and can be a challenge to net. If you are lucky you may catch one perched stream-side or even in foraging habitat away from the stream, pausing to eat some prey.