Jumping bristletails used to be classified with the silverfish (the blameless Jumping bristletail is still lumped with silverfish on some exterminator\u2019s websites), but now they\u2019re in their own order. In defining an animal scientifically, the groupings move from the most general umbrella to the most specific umbrella. Kingdom (Animalia) comes first, the biggest umbrella, then Phylum (Arthropoda), then Class (Insecta), then Order, then Family, Genus, and finally Species. <\/p>\n\n\n\n Jumping bristletails have two different order names. The newer name is Microcoryphia (\u201csmall head<\/em>\u201d), and the older appellation is Order Archaeognatha (\u201cancient jaw<\/em>\u201d), which refers to the way the mandible connects to the insect. Whichever order name you pick, Jumping bristletails are alone in it. That 396 million year old \u201csilverfish\u201d had the new-fangled double-jointed (dicondylic<\/em>) mandible, but Jumping bristletails have the original equipment, a single (monocondylic<\/em>), knuckle-like joint\/articulation that allows its mouthparts to rotate or twist. Ancient insect jaws probably resembled those of Jumping bristletails, but most insects developed from a side branch that sprouted from the insect family tree early on. Some scientists consider the Jumping bristletail to be the least <\/em>evolutionarily changed of any living insect – a chip off a very old block.<\/p>\n\n\n\n There are two Jumping bristletail families worldwide, the largest of which is Machilidae. Both families occur in North America, as do about two dozen of the 350 to 450 species of the world\u2019s Jumping bristletails (we even have an introduced species). <\/p>\n\n\n\n (No \u2013 the BugLady is not going to try to name a genus or species for this one, but if she was a betting woman, she\u2019d put a little money on Pedetontus<\/em> saltator.<\/em>)<\/p>\n\n\n\n Back in the (Permian) day, there were many wingless insects.\u00a0Today, the vast majority of insects have wings, and many of those that have wings have two pairs of them.\u00a0Most of the species that are wingless derive from ancestors that once had them.\u00a0Not so the Jumping bristletail and the silverfish, who are\u00a0primitively\/primarily wingless<\/em>\u00a0\u2013 their ancestors never enjoyed flight.\u00a0<\/p>\n\n\n\n As a group Jumping bristletails are drab (though a close look may reveal a variety of color patterns, and the BugLady\u2019s bristletail is downright iridescent), scale-covered, cylindrical, hump-backed (silverfish are flat), and generally less than three-quarters of an-inch long. At one end they have sensory antennae and both simple and compound eyes (with their simple eyes, silverfish are blind to all but light and dark), and at the other end, three caudal filaments \u2013 two sensitive cerci and a central terminal filament. Fringes of hairs on the rear filaments explain the \u201cbristletail\u201d part.<\/p>\n\n\n\n They have the requisite six legs, but attached to the underside of some abdominal segments are additional pairs of short, moveable appendages called \u201cstyli<\/em>\u201d (plural of stylus<\/em>) that serve as sensors of their substrate and that may be vestigial legs left over from their ancestors. Jumping bristletails dehydrate easily and must absorb water from their environment through tiny, paired sacs that are located on several abdominal segments and that work like pockets turned inside out (OK \u2013 \u201cmembranous, eversible sac-like vesicles<\/em>\u201d). Here\u2019s an article with pictures showing their iridescence and a video of bristletails in action<\/a>.<\/p>\n\n\n\n As their name suggests, they jump – six inches and more – which silverfish can\u2019t do. This they accomplish by pushing up with their legs while contracting the muscles in their abdomen to arch their body downward. They can run fast, too. Jumping is their main defense, but like silverfish, a dense covering of scales renders them slippery and helps them escape from the clutches of their predators.<\/p>\n\n\n\n In the \u201cIs There a Video of That?\u201d category (and there undoubtedly is one), consider Stephen P. Yanoviak\u2019s research that looked at Jumping bristletails for clues to the evolution of insect flight. When a Jumping bristletail leaps from tree to tree, its drop is augmented by \u201csteering,\u201d using the long terminal filament (\u201cdirected aerial descent<\/em>\u201d) (kind of like a flying squirrel). Yanoviak dusted Jumping bristletails with orange fluorescent powder and dropped them from branches high in rainforest trees. Results showed that the filament was vital to a successful glide and landing, and Yanoviak suggests that because these wingless, arboreal insects had \u201cflight\u201d under control, winged flight probably originated from terrestrial insects.<\/p>\n\n\n\n Jumping bristletails live in a wide variety of conditions, from Arctic to desert, and they especially like leaf litter, bark, rock crevices, and rocky seashores. The North Carolina State University Entomology Pages <\/em>rank Jumping bristletails as \u201ccommon in grassy or wooded habitats<\/em>.\u201d They are found in the nooks and crannies of the world, where they shelter during the day and from which they perambulate at night. They rarely come indoors. <\/p>\n\n\n\n Herbivores and decomposers\/recyclers, they use their mouthparts to feed on algae, fungi, lichens, mosses, and soft, decaying organic material, though a few sources said that they eat tiny invertebrates, too (one source said that they pick at their food rather than chewing it). They don\u2019t\/can\u2019t bite people. They are eaten by birds, centipedes, spiders, mites, ants, and flies. <\/p>\n\n\n\n Ancient mouth; ancient winglessness, ancient reproduction, and ancient metamorphosis. Males court, sometimes with elaborate dances, then leave a sperm packet for her to pick up (indirect sperm transfer<\/em>). She may lay as many as 30 eggs, but to lay more, she must dance again. Some species skip the dance and reproduce by parthenogenesis \u2013 females reproduce without input from males. Young Jumping bristletails have an ametabolous <\/em>development – they start as miniatures of the adults and simply grow, shedding eight times over the course of about two years before reaching adulthood. Unlike most other insects, they continue to shed as adults and may live for two additional years. Each time they molt, they must first cement themselves to the substrate – a stick, rock, etc. – using fecal material as a glue. Should the glue fail, the insect will not molt, but die. <\/p>\n\n\n\n Interesting Jumping bristletail facts:<\/p>\n\n\n\n Small, yes. Old, oh yes. But not uncomplicated.<\/p>\n\n\n\n The BugLady<\/em><\/p>\n\n\n\n PS \u2013 Road Trip<\/a>!!!! <\/p>\n\n\n Note: All links leave to external sites. Salutations, BugFans, The BugLady has been busy \u2013 here\u2019s a slightly-spruced-up version of an episode that she posted 10 years ago. The Jumping bristletail that inspired it remains the only one she\u2019s ever seen. …<\/p>\n","protected":false},"author":32664,"featured_media":14486,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","uwm_wg_additional_authors":[]},"categories":[8],"tags":[607,637,614,732,731,374],"class_list":["post-14485","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bug-of-the-week","tag-bugs","tag-critters","tag-insects","tag-jumping-bristletail","tag-jumping-bristletail-retread","tag-silverfish"],"yoast_head":"\n![\"Bug](\"https:\/\/uwm.edu\/field-station\/wp-content\/uploads\/sites\/380\/2023\/11\/jmpng-bristletail13-1.jpg\")
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