New York Natural Heritage Program
Extra-striped Snaketail
Ophiogomphus anomalus Harvey, 1898

Identifying Characteristics [-]
Snaketails are characterized by their bright green thorax and are part of the Clubtail family. As their name suggests, Clubtails have an enlarged tip on the end of their abdomens, giving them a club-like appearance. The Extra-striped Snaketail has green lateral thoracic stripes forming an N shape above the base of the legs (Mead 2003). They are an average of 1.7 inches long. They have green eyes and, as with all gomphids, their eyes are separated dorsally. This species has black legs and narrow black cross-stripes on their face (Dunkle 2000). They have a black abdomen with a moderately widened "club" at the end and yellow dorsal spots. The dorsal spots of abdominal segments 9 and 10 are more rounded than those of other segments. Segments 7-10 have yellow side spots of various shapes (Mead 2003).

Behavior [-]
Adult Extra-striped Snaketails spend most of their time in treetops away from water, but they can occasionally be found in bushes near riffle areas of rivers (Dunkle 2000). Larvae are aquatic and burrow in the sandy substrate of rivers (Mead 2003). Nevertheless, larval drift could be important because the highest numbers of emerging Ophiogomphids in Maine were found at the furthest downstream station on the Aroostook River, but Ophiogomphids are rarely captured in drift samples (Gibbs et al, 2004). Extra-stiped larvae emerge from the water to shed their larval skin and transform into adult form early in the spring during a short, synchronous period with five other Ophiogomphus species (Gibbs et al. 2004). Maine researchers showed that the larval life histories of the six co-occurring Ophiogomphid species had a high degree of spatial and temporal overlap. This lack of ecological differentiation could suggest that this larval assemblage has evolved a suite of convergent traits that enhance fitness in a riverine habitat. Alternatively, a similar scenario is also seen in certain damselflies, where differentiation of the mate recognition system in winged adults has driven a radiation (Gibbs et al. 2004). An identical Ophiogomphid assemblage occurs on the upper Hudson River in Warren County and it is likely the same ecological and evolutionary factors are in play at this locale; however Ophiogomphus anomalus appears to be found in lower numbers here than was recorded in Maine (Gibbs et al. 2004, New York Natural Heritage Program 2009).

Diet [-]
Extra-striped Snaketail adults feed on mosquitoes, flies, damselflies, moths, and butterflies (Lee 2007). Larvae are important predators, especially of chironomids, but also other smaller burrowing aquatic invertebrates such as water mites and mayfly nymphs (Gibbs et al. 2004).
Extra-striped Snaketail Images
click to enlarge
The Best Time to See
Adults are active from early June through early August (New York Natural Heritage Program 2009, Mead 2003). In the Adirondacks, larvae have been found to emerge around the last week of May or first week of June, with teneral adults observed in the mid-morning (New York Natural Heritage Program 2009).
Present Reproducing
The time of year you would expect to find Extra-striped Snaketail present (blue shading) and reproducing (orange shading) in New York.
Similar Species
  • Boreal Snaketail (Ophiogomphus colubrinus)
    The Boreal Snaketail is similar in appearance to the Extra-Striped Snaketail, but has pale thighs instead of all-black legs, and lacks the N shaped thoracic stripe (Mead 2003).
  • Rapids Clubtail (Gomphus quadricolor)
    The Rapids Clubtail has reduced or absent yellow side spots on abdominal segments 8-9 (Dunkle 2000).