Salutations, BugFans,<\/p>\n
The story begins on the river, two years ago, with flat, tan, elongated exuviae<\/em> clinging to rocks and vegetation at the water\u2019s edge (the BugLady didn\u2019t know then, but she suspected, that the large, pale tenerals<\/em> that flew from the ground, straight up into the trees, were part of the story, too).<\/p>\n Arrow clubtail exuviae, said BugFan Bob.\u00a0Arrow clubtail?<\/p>\n Is the Arrow clubtail rare?\u00a0Is it new to the area?\u00a0No and no (though the BugLady was new to the park and to the species).\u00a0The hunt was on.<\/p>\n Arrow clubtails are in the order Odonata and the Clubtail family, Gomphidae, which includes dragonflies with grand names like dragonhunter, snaketail, spinyleg, and sanddragon.\u00a0According to Paulson, in Dragonflies and Damselflies of the East<\/em>, \u201calert and fast-flying, many of them rare, local, and with brief flight seasons, clubtails are considered the most exciting group by many dragonfly enthusiasts.\u201d\u00a0Here\u2019s why:<\/p>\n Paulson goes on to say that \u201cdespite their great diversity and local abundance, their behavior is very poorly known.\u201d<\/p>\n [metaslider id=515]<\/p>\n Clubtails get their name from the three, variously-flared segments that form a noticeable \u201cclub\u201d at the end of the abdomen of many (but not all) species.\u00a0The club is more prominent in males, and they will raise the end of the abdomen to display it, even in flight.\u00a0Most clubtails are medium-sized—about 2\u201d to 2 \u00bd\u201d long—with unspotted wings and with striped bodies that use the zebra\u2019s strategy of disruptive coloration as camouflage.\u00a0What Clubtails have in common is that their eyes (usually green, blue or gray) do not touch each other on the tops of their heads like those of most other dragonflies.<\/p>\n There are about one hundred species north of Mexico (900 world-wide), and they generally prefer well-oxygenated, running water rather than still.\u00a0Lacking an ovipositor, the female releases eggs by tapping the tip of her abdomen on the water, unguarded by the male.\u00a0The eggs overwinter and hatch when the water warms in the next spring; depending on water temperature, they may live underwater as naiads for several years.\u00a0Stocky, young Gomphids are ambush predators, burrowing shallowly into the substrate, lurking with only their eyes exposed (the better to see you with, my dear) and the tip of their abdomen (for breathing).<\/p>\n When the BugLady first took entomology, oh-so-long ago, the immature stage of insects that practiced Complete metamorphosis (egg to larva to pupa to adult—flies, beetles, wasps, etc.) were called larvae.\u00a0 Immatures of terrestrial insects with Incomplete metamorphosis (that hatch looking like their elders and add reproductive equipment and (usually) wings as they grow—true bugs, grasshoppers, etc.) were called nymphs, and immatures of aquatic species with Incomplete metamorphosis were called naiads.\u00a0This distinction was espoused a century ago by the great Cornell entomologist John Henry Comstock (in whose Hall the BugLady studied bugs).\u00a0Convention has relaxed in recent years and young Odonates are called all three, but old habits die hard.<\/p>\n There were more exuviae in the summer of 2015 and a few in the first week of July, 2016.\u00a0Then, on July 11, the BugLady saw a stubby, inch-high projection on top of a rock about six feet off shore.\u00a0An emerging Arrow clubtail!\u00a0The BugLady\u2019s zoom lens chose this moment to initiate a conversation about the Zen of focusing on small objects, resulting in an abundance of shots that are more \u201cClose enough for government work\u201d than they are \u201ctack sharp.\u201d\u00a0Thanks to BugFan Freda for contributing a picture.<\/p>\n [metaslider id=516]<\/p>\n Arrow clubtails (Stylurus spiniceps<\/em>) are fairly-common\/widespread-but-not-abundant inhabitants of the northeast quadrant of the U.S.\u00a0They prefer good-sized rivers with muddy\/sandy bottoms and with trees along the edges.\u00a0Unlike the Pond clubtails that the BugLady was chasing in spring (Ashy, Dusky, Lancet, Midland, Lilypad), the Arrow clubtail is a Hanging clubtail, one of 11 North American species in the genus Stylurus<\/em> (\u201changing\u201d because of their tendency to perch on leaves that then bend down under their weight; they don\u2019t really hang like darners).<\/p>\n Arrow clubtails are spectacular, both males http:\/\/bugguide.net\/node\/view\/17871\/bgimage<\/a> and females http:\/\/bugguide.net\/node\/view\/17869\/bgimage<\/a>. At 2 \u00bd\u201d long, they\u2019re Wisconsin\u2019s largest and longest Stylurus<\/em>, and they\u2019re unique in that the ninth segment of the abdomen is noticeably longer than the eighth.<\/p>\n Adults are strong flyers that dart out at their prey from perches and that may feed in the air. The reason the adults are tough to find is that they fly long patrols not far above the water\u2019s surface (with their abdomen slightly tipped up), and then they go sit high up in a tree.\u00a0Paulson describes the flight of a male patrolling his territory as interspersing a \u201chovering, bouncy flight that seems to have come from alternating fluttering and gliding, with extremely rapid, low, straight flight \u201clike an arrow.\u201d\u00a0They are more active in late afternoon until dark.<\/p>\n Females deposit eggs in rapids or riffles areas but the naiads find more sluggish water for their development.\u00a0When it\u2019s time to assume an adult form, they crawl out of the water for only a short distance to do so (the BugLady found emerging Arrow clubtails after 3:00 PM; she hasn\u2019t seen one crawl out of the water yet, but she has found several that didn\u2019t have the strength to exit their skins). Immature\/juvenile Arrow clubtails frequent the woods (for a \u201clengthy period,\u201d says Paulson) until they are ready to breed.<\/p>\n On July 13, the BugLady found a dozen exuviae that had not been there two days earlier.\u00a0And, she saw five emerged\/emerging Arrow clubtails.\u00a0And two more on July 16.\u00a0It made her wonder if Arrow clubtail emergence might be loosely synchronized, so she moseyed through some of the literature and found some hints of synchronicity in related dragonflies, but nothing about the Arrow clubtail itself. In a report about dragonflies of the Canadian grasslands, Robert A. Cannings writes about the Elusive clubtail (Stylurus notatus<\/em>) that \u201cExperienced observers in Manitoba seldom see a mature adult, but sometimes lucky people have come across a mass emergence or thousands of exuviae on a river bank.\u201d\u00a0 Another observer recorded an overnight appearance of 230 exuviae of a different clubtail genus on a 20 foot stretch of the New River in Virginia.<\/p>\n What would cause this phenomenon? One factor might be cold\/rainy weather that stalls the naiads, allowing a large number to reach the point of emergence at the same time.\u00a0Water quality and\/or crowding have also been suggested. Large numbers of mature larvae (hellgrammites<\/em>) of the totally un-related Dobsonfly (Order Neuroptera) will emerge to pupate when stimulated by a thunderstorm. The BugLady also wonders about how the naiad decides where to pull out and emerge. How does it know that there will be trees nearby to shelter in (she generally finds exuviae on surfaces that are in the sun all day)?<\/p>\n The emerging dragonflies takes a short rest after pushing their head and \u201cshoulders\u201d out of their old skin, but then the abdomen slides out all at once. A teneral spends about 30 minutes lengthening and strengthening after it emerges, and then is capable of flight.\u00a0On two occasions, the BugLady took a picture, looked down to check the image on the screen, and looked up to find the dragonfly gone.\u00a0Their maiden flight, says BugFan Freda, \u201cis amazingly strong,\u201d and is preceded by a quivering of the wings (to warm up the flight muscles in the thorax).\u00a0The BugLady observed one maiden voyage that ended at an altitude of about 25 feet, when the arc of the dragonfly\u2019s trajectory intersected with that of an Eastern Phoebe.<\/p>\n The BugLady will keep walking the river, looking for adult arrow clubtails in their adult plumage (and enjoying the dancers, rubyspots, amberwings, whitetails and widows).<\/p>\n Maybe this\u2019s what German poet Friedrich Schiller had in mind when he wrote \u201cOde to Joy\u201d (Beethoven just put it to music).<\/p>\n Arrow Clubtails<\/strong> (Stylurus spiniceps<\/em>) are fairly-common\/widespread-but-not-abundant inhabitants of the northeast quadrant of the U.S. They prefer good-sized rivers with muddy\/sandy bottoms and with trees along the edges. Unlike the Pond clubtails, the Arrow clubtail is a Hanging clubtail, one of 11 North American species in the genus Stylurus<\/em>.<\/p>\n","protected":false},"author":778,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","uwm_wg_additional_authors":[]},"categories":[8],"tags":[11],"class_list":["post-492","post","type-post","status-publish","format-standard","hentry","category-bug-of-the-week","tag-dragonflies"],"yoast_head":"\nArrow Clubtails<\/h3>\n
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\nThe BugLady<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"