FIELD ENTOMOLOGY : EEB 252

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Lecture 5: PALEOPTERA & PLECOPTERA

SUMMARY OF INSECT CLASSIFICATION - ORDINAL & SUBORDINAL LEVEL

ENTOGNATHOUS HEXAPODS

(1) Protura: 400

(2) Collembola (springtails): 6,000

Arthropleona

Symphypleona

(3) Diplura: 800

 

INSECTAN HEXAPODS

 

(4) Microcoryphia (jumping bristletails): 350

(5) Thysanura (silverfish & firebrats): 370

 

Pterygota (winged insects)

Paleoptera (no wing folding)

(6) Ephemeroptera (mayflies): 2,500

(7) Odonata (dragon & damselflies): 5,500

Zygoptera

Anisoptera

Anisozygoptera

Neoptera (wings can fold flat over body)

Orthopterodea (orthopteroid complex)

Pleconeoptera

(8) Plecoptera (stoneflies): 2,000

Blattoneoptera

(9) Grylloblattodea (rock-crawlers): 24

(10) Zoraptera: 28

(11) Dermaptera (earwigs): 1,800

Hemimerina

Arixeniina

Forficulina

(12) Dictyoptera

Blattodea (cockroaches): 3,500

Mantodea (mantises): 1,800

Isoptera (termites): 2,300

Orthoneoptera

(13) Phasmatodea (stick & leaf insects): 2,500

(14) Embioptera (webspinners): 200 (2000?)

(15) Orthoptera (grasshoppers, katydids, crickets)

Ensifera (long-horned): 11,000

Caelifera (short-horned): 10,000

 

Hemipterodea (hemipteroid complex)

Hemineoptera

 

(16) Thysanoptera: 4,500
Terrebrantia

Tubilifera

(17) Hemiptera (bugs): 80,000

Sternorrhyncha

Auchenorrhyncha

Heteroptera

Psocodea

(18) Psocoptera (book lice): 3,000
Trogiomorpha

Troctomorpha

Psocomorpha

(19) Phthiraptera

Mallophaga (biting lice): 5,000

Anoplura (sucking lice): 500

Endopterygota (Holometabola)

Endoneoptera

Hymenopterodea

(20) Hymenoptera: 180,000
Symphyta (sawflies & woodwasps)

Apocrita (bees, wasps, & ants)

Mecopterida (Panorpodea)

Antliophora

(21) Mecoptera (scorpionflies): 500

(22) Siphonaptera (fleas): 2,000

(23) Diptera: 110,000

Nematocera

Brachycera

(24) Strepsiptera (twisted winged parasites): 532

Amphiesmenoptera

(25) Trichoptera (caddisflies): 7,000

(26) Lepidoptera (moths & butterflies): 120,000

 

Neuropterodea

(27) Coleoptera (beetles): 400,000
Archostemmata

Myxophaga

Adephaga

Polyphaga

Neuropterida

(28) Megaloptera (dobson & alderflies): 300

(29) Raphidioptera (snakeflies): 175

(30) Neuroptera (lacewings): 4,600

 

 

EPHEMEROPTERA

 

INTRODUCTION: Mayflies. A small order of 2,500 species worldwide, ca. 620 species in North America north of Mexico. The most ancient extant lineage of winged insects. Unlike all other insects, Ephemeroptera have a winged sub-adult stage. The adults do not feed and live only a few minutes to a few days.

RECOGNITION: Nymphs- external wingpads present, tarsi with only one claw, abdomen usually ending in 3 caudal filaments (sometimes 2). Adults- Hind wings much smaller than forewings, held rigidly upright when at rest (in some groups the hind wings are reduced further or absent).

HABITATS: Nymphs of all species live in freshwater. Greater species richness is found in running water, but larger populations (among fewer species) are more often from bodies of standing water. The nymphs of most species are general collectors-gatherers. Some species are filterers or scrapers and there are a few predatory species.

COLLECTING: Nymphs are the preferred form as many adults are secretive. Nymphs are generally abundant and easily collected by routine benthic sampling, but must be handled with care. Many species are restricted to shoreline areas. Some benthic forms from large rivers are rarely collected. Active swimmers may avoid nets. Adults can be collected while swarming or while resting on structures. Nocturnal species are often attracted to lights.

The immatures are best collected into a weak formalin solution, although 70% ETOH is acceptable. The adults are too fragile for dry mounting and, like the nymphs, must remain in ETOH permanently.

TAXONOMY: Messy! No two references will agree on Classifications. Ephemeropteran taxonomy has not been reworked from a modern, phylogenetic perspective and numerous changes to any given current classification are expected. Merritt and Cummins (1984) is an excellent book with keys to genera for North America.

 

LITERATURE:

Berner, L. 1950. Mayflies of Florida. Univ. Florida Studies. Biol. Sci. Ser. 4:267 pp.

Edmunds, G. F., Jr. and R. K. Allen. 1978. Order Ephemeroptera, p. 75-94. In Immature Insects vol. 1, ed. F. W. Stehr. Dubuque, Iowa: Kendall/Hunt.

Edmunds, G. F., Jr., S. L. Jensen, and L. Berner. 1976. The mayflies of North and Central America. Minneapolis: Univ. Minn. Press, 330 pp.

Merritt, R. W. and K. W. Cummins. eds. 1984. An introduction to the aquatic insects of North America, 2nd ed. Kendal/Hunt Publishing Co., Dubuque, Iowa 722 pp. {note that the 3rd edition has recently been published}

 

 

ODONATA

INTRODUCTION: Dragonflies and damselflies. A medium sized order of about 5,500 species worldwide, mostly in the tropics. In North America north of Mexico there are about 415 species in 11 families. In Connecticut there are 46 species of damselflies (Zygoptera) and about 110 dragonfly (Anisoptera) species in New England. The Odonata is one of the best documented insect groups due to the this group's popularity among both professional and amateur collectors. Odonates are one of the few invertebrate groups receiving significant attention from the conservation community.

RECOGNITION: Nymphs- external wingpads present, chewing mouthparts with labium modified into a mask-like extendible structure for grasping prey. Adults- two pair of large, membranous, non-folding wings of ca. equal size, antennae short and bristle-like, abdomen lacking long terminal filaments.

HABITATS: Nymphs are found only in freshwater (except a few terrestrials in Hawaii). More common and greater species richness in standing water. Large, warm rivers hold populations but few occur in cold running water. The adults are long-lived, very active predators and display complex territorial guarding behaviors. Both the immatures and adults are active predators. Large, mobile dragonfly larvae are less common in lakes with fish, and thus fishless lakes (a rare, rare habitat) support unique assemblages of odonates.

COLLECTING: Collections of adults, immatures and last-instar exuvia are relatively easy to make. The adults, although difficult to catch are best netted with a wide-diameter, strong & lightweight net. These should be placed in glassine envelopes alive, and kept away from temperature extremes for ca. 24 hrs so that they will void their intestinal tracts. Then while living, they should be placed into an acetone bath (for large dragonflies, it is best to inject acetone into the thorax and/or abdomen prior to placing in the bath). The acetone bath dissolves fats, oils and waxes as well as removes water by osmosis and preserves the colors better than any other known method. After 24 hr in acetone they should be allowed to dry completely and then be placed into clear, plastic envelopes with a 3x5" card bearing all the collection data.

Ideally, the immatures should be kept alive and reared to adults in the lab so one may associate the adult with the last instar exuvium (see Westfall (1987) for rearing tips). The immatures are best killed with a fixative such as a mild formalin solution, such as Kahle's solution2, although 70% ETOH is acceptable. The nymphs are usually obtained by scooping up suitable substrate and picking the nymphs by hand. The nymphs must be stored permanently in vials of ETOH. Exuvia may be found on emergent vegetation and other surfaces near the water line. Exuvia may be pinned dry, although some prefer to store them in vials with 70% ETOH.

TAXONOMY: There are two suborder in our region: the Anisoptera (dragonflies) and the Zygoptera (damselflies). The adults can be distinguished easily as the Anisoptera are almost always larger and cannot fold their wings together above their body whereas the Zygoptera are usually quite small, with much narrower abdomens, and they can fold their wings back and together (upright) above their body. The immatures may be distinguished by their caudal filaments- the Anisoptera lack filaments (figure above, right) and the Zygoptera usually have 3 filaments (figure above, middle).

 

LITERATURE:

Carpenter, V. 1991. Dragonflies and damselflies of Cape Cod. The Cape Cod Museum of Natural History, Natural History Series No. 4. 80 pp.

Donnelly, T. W. 1992. The Odonata of New York state. Bull. Amer. Odonatol. 1(1):45-51.

Garman, P. 1927. The Odonata or dragonflies of Connecticut. State Geological and Natural Histiry Survey, Hartford. 331 pp.

Garrison, R. W. 1991. A synonymic list of the new world Odonata. Argia, 3:1-30.

Miller, P. L. 1987. Dragonflies. Cambridge University Press, Cambridge.

Westfall, M. J., Jr., 1984. Odonata, pp. 126-176 In R. W. Merritt and K. W. Cummins. eds. 1984. An introduction to the aquatic insects of North America, 2nd ed. Kendal/Hunt Publishing Co., Dubuque, Iowa 722 pp. {note that the 3rd edition of this book has recently been published}

Westfall, M. J., Jr., 1987. Order Odonata, pp. 95-117 In Immature Insects, vol. 1, ed. F. W. Stehr. Dubuque, Iowa: Kendall/Hunt.

 

 

 

PLECOPTERA

INTRODUCTION: Stoneflies. A small, homogenous order of 17 families and about 2000 species worldwide. In North America north of Mexico there are 595 species in 9 families. McCafferty et al. (1990) estimate that another 50 North American species await description.

RECOGNITION: Soft bodied and range in length from 4 to 50 mm. Nymphs- external wingpads present, unmodified chewing mouthparts, tarsi with 2 claws (recall mayfly nymphs have only 1 claw per tarsus), usually with two obvious cerci. Adults- 2 pairs of membranous wings held flat over the abdomen (though in some species the wings are reduced), tarsi 2-3 segmented, antennae conspicuous, cerci usually conspicuous.

HABITATS: Cold, unpolluted, fresh water systems contain stoneflies. The greatest stonefly species richness occurs in cold, running water habitats (they require high dissolved oxygen levels) a few species occur in cold standing water but none occur in warm standing water. Some species are hyporheic (occur below the river channel, among the rock and dirt channels saturated by river water), many species are rare. They are poor fliers and rarely found far from water. In many species the adults do not feed and thus have reduced mouthparts.

COLLECTING: The adults are the preferred stage as they are more easily collected than the immatures. Early morning is often the best time to collect adults. Because stoneflies emerge throughout the year (even during the winter) a complete species list for a region requires year-round collecting. These can be collected by sweeping vegetation along the banks of streams and rivers. Check bridges for resting adults. During the summer, some species can be found at lights.

The nymphs can be found in benthic samples. Adults should be collected and stored in 70% ethanol. Nymphs are best fixed in Kahle's solution and transferred to 70% ethanol for permanent storage after a few days. Fully mature nymphs (with black wing pads) can usually be reared to adult in the lab if kept cool and wet.

TAXONOMY: Has received more attention than the mayflies and the North American fauna is nearing completion. There are two major 'groups' of families: the Euholognatha that have the paraglossae and glossae (structures on the labium) similar in size and the Systellognatha that have the glossae much smaller than the paraglossae.

 

LITERATURE:

 

Baumann, R. W. 1987. Order Plecoptera, pp. 186-195. In Immature Insects, vol. 1, ed. F. W. Stehr. Dubuque, Iowa: Kendall/Hunt.

Hitchcock, S. W. 1974. Guide to the insects of Connecticut. Part VII. The Plecoptera or stoneflies of Connecticut. Conn. State Geol. Nat. Hist. Surv. Bull. 107:1-262

Harper, P. P. Plecoptera, pp. 182-230. In R. W. Merritt and K. W. Cummins. eds. 1984. An introduction to the aquatic insects of North America, 2nd ed. Kendal/Hunt Publishing Co., Dubuque, Iowa 722 pp. {note that the 3rd edition of this book has recently been published}

Stark, B. P., S. W. Szczytko and R. W. Baumann. 1986. North American stoneflies (Plecoptera): Systematics, distribution and taxonomic references. Great Basin Natur. 46:383-397.

Stewart, K. W. and B. P. Stark. 1988. Nymphs of North American stonefly genera (Plecoptera) Entomological Society of America, Thomas Say Foundation XII. 460 pp.

 


FIELD ENTOMOLOGY : EEB 252

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