The Plecopteridan Orders

Plecoptera Embioptera Zoraptera PLECOPTERA - Stoneflies PLECOPTERA - Stoneflies SYNAPOMORPHIES

“Looped” gonads - anterior apices of left and right ovaries and testes fused in middle

Tarsomeres reduced to 3 PLECOPTERA - Stoneflies SYNAPOMORPHIES

Nymphs aquatic PLECOPTERA - Stoneflies Other characteristics: • Soft bodied, flattened, drab in color • Wings folded flat over dorsum; forewing long, narrow, hindwing shorter, with broad basal area which is folded fanwise at rest • Three tarsal segments with two tarsal claws

Hind wing folded (when at rest)

Hind wing expanded (as in flight) PLECOPTERA - Stoneflies Other characteristics: • Long, slender antennae • 2 cerci at tip of abdomen - generally long and slender • Nymphs very similar to adults, but with branched thoracic gills

cercus PLECOPTERA - Stoneflies Other characteristics: • Adults mouthparts complete, but with reduced mandibles Antarctoperlaria - 4 families Southern Hemisphere = Gondwanaland

Euholognatha - 6 families

Arctoperlaria Northern Hemisphere Systellognatha - 6 families = Laurasia

Habitat & Habits:

• Incomplete metamorphosis (hemimetabolous) • Univoltine (as short as 3 months), some semivoltine (2-3 years) • 12-22 instars • Larvae of Antarctoperlaria and Euholognatha are primarily leaf detritivores (bacteria and fungi), those of Systellognatha primarily carnivorous • Larvae crawl out of water to emerge • Males emerge before females; males attract females by beating abdomen on substrate ==> drumming behavior; only virgin females answer; mating takes place on ground. Species specific signals. John Sandberg’s StoneflyHome http://www.ias.unt.edu/~StoneflyHome/Home/ Habitat & Habits:

• Female carries eggs on tip of abdomen prior to oviposition • Oviposition: 1. run or fly over water and dip abdomen on surface releasing eggs 2. drop eggs from air 3. deposit along banks 4. crawl under water • Adults are short lived (days-month), do not feed (some species feed on pollen, buds, moss, etc.) Habitat & Habits:

• Winter stoneflies - Euholognatha - emerge in winter and spring. Most cold season adapted of all insects. Insulate within ice or snow or under rocks and debris. • One species, Utacapnia tahoensis, spends its entire life history under water in lake Tahoe, at depths of 70 m. • Nymphs found in streams, among stones, gravel, detritus, etc., occasionally along shores of cold northern lakes. Rapid crawlers, but nymphs capable of swimming by lateral undulations of body Habitat & Habits:

• Very sensitive to pollution, especially organic enrichment that reduces dissolved oxygen. • Young instars especially are found in hyporheic habitats. • Some species ventilate gills by doing "push ups" Collecting & Preserving: • Collect adults at lights or by sweeping, beating, and netting, also turn over shoreline rocks and debris. • Also collect in late winter and early spring. • Preserve adults and nymphs in 80% EtOH

Diversity and distribution: • ca. 2,000 species worldwide • ca. 750 spp., 9 families North America

EMBIOPTERA - Webspinners What is the correct name of the order? Embioptera Embiodea Embiidina from embios, Greek, for life, in life, long lived, or embodied with life EMBIOPTERA - Webspinners SYNAPOMORPHIES • Basal segment of fore tarsus greatly swollen, containing numerous silk glands. Silk used for spinning tubular galleries

• Cerci short, one- or two- segmented

• Asymmetrical male genitalia

• Females always apterous • Male wings, when retained, with distinctive simplified venation; wing veins lie in blood sinuses that inflate EMBIOPTERA - Webspinners SYNAPOMORPHIES

• Paraglossa with additional, dorsal flexor muscle

• Head prognathous, with true gula (between submentum and foramen)

• Ocelli absent Other characteristics: • Soft bodied; males superficially resemble small stoneflies • Longitudinal wing veins are not sclerotized and form hollow - “blood sinuses.” Hemolymph is pumped through to inflate wings, as during flight. When hemolymph is withdrawn, wings deflate. Wing can even flip backwards when males are running through galleries. Wings dehiscent. Habitat & Habits:

• Incomplete metamorphosis (hemimetabolous) • Gregarious, live in colonies in soil or debris among mosses and lichens, usually at base of trees. • Spin silk to line galleries. Both adults and nymphs produce silk. • Silk from ectodermal glands in fore basitarsus, emitted from hollow setae. • Active, run rapidly, often backwards. • Feed on dead plant material. • Eggs laid in galleries, often covered with debris or chewed food; females brood their own eggs and attend nymphs, but this behavior is facultative. Collecting & Preserving: • Collect by searching out galleries. Males attracted to lights. • Preserve adults and nymphs in 80% EtOH, although males may be pinned.

Diversity and distribution: • ca. 360 species in 9 families worldwide, mostly in the tropics • 11 spp., 3 families North America, from the south and southwest

ZORAPTERA - zorapterans, angel insects ZORAPTERA - zorapterans, angel insects SYNAPOMORPHIES

• Minute, < 3 mm • Wings (when present) with peculiar, but simple venation • Hind wings distinctly smaller than forewings • 2 tarsal segments • Stout spines on metafemur ZORAPTERA - zorapterans, angel insects SYNAPOMORPHIES

• 9-segmented, moniliform antennae • Unsegmented cerci • Female postabdomen with subgenital plate on venter 8 • Only 6 Malpighian tubules • Only 2 abdominal ganglia Other characteristics: • Each species has 2 adult morphs: 1. Winged morph or “alate” with dark sclerotization, eyes, and ocelli 2. Wingless morph (neotenic), pale in color, lacking eyes and ocelli Habitat & Habits:

• Incomplete metamorphosis (hemimetabolous) • Occur in gregarious colonies under slabs of wood buried in sawdust, under bark, in rotting logs, in termite nests; in northern part of range found only in sawdust piles which remain warm in winter. • Feed on mites, other small arthropods, nematodes; fungal spores and hyphae. • Habitat requirements similar to ants and termites => warmth, moisture, fungus infected rotting wood. • During most of season, only neotenic forms found, but as resources become limited, alates form and disperse to new sites; females mate prior to dispersal resulting in low numbers of alate males. • After forming new colony, wings are shed. Collecting & Preserving:

• Search through habitat with aspirator or use Berlese/Tullgren funnel or Winkler/Moczarski eclector, preserve in 80% EtOH • Mount on slides Diversity and distribution:

• Only 32 species in one genus, Zorotypus (Zorotypidae) around the world, except Australia

• 2 species in continental U.S. 1. Zorotypus hubbardi, eastern deciduous forests from Florida to Pennsylvania, west to Iowa and Texas 2. Zorotypus synderi, Florida and Jamaica Evolution of the Plecopterida

Plecoptera Embioptera Zoraptera The enigmatic position of Zoraptera

Various workers over the last 90 years have considered it the living sister group to: • Isoptera • Isoptera + Blattodea • Paraneoptera • Embioptera • Holometabola • Dermaptera • Dermaptera + Dictyoptera • basal within Thysanoptera • basal within Psocoptera • unresolved among Orthoptera, Phasmatodea, & Embioptera

Best current evidence places it within Polyneoptera as the sister order to Embioptera Plecoptera PLECOPTERIDA Embioptera

Zoraptera

Dermaptera

Grylloblattodea

Mantophasmatodea

Phasmatodea POLYNEOPTERA ORTHOPTERIDA Orthoptera

Blattodea

DICTYOPTERA Isoptera

Mantodea Plecoptera PLECOPTERIDA Embioptera

• Ovipositor lost • Suppression of male styli Zoraptera

• Anal lobe of hind wing lost • Cerci reduced to 1 or 2 segments • Wings dehiscent • Hind femora enlarged, with distinctive musculature • Communal behavior • Others (see Grimaldi & Engel)