| Good sources of help for keying insects to family: | |
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| Videos of aquatic invertebrates (and some fish) in action: |
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Phylum Arthropoda - Superclass Hexapoda
Class Parainsecta, Order
Collembola - springtails, snow fleas
- mouthparts
internalized, mandible and maxilla partially contained within head capsule
(endognathous)
- wingless (apterous)
- metamorphosis - none,
ametabolous
- club-shaped antennae
- furcula - a forked
tail from underside of abdomen when released acts like a spring vaulting
the insect into the air for movement
- collophore - a tube-like
projection from lower abdomen thought to aid in water regulation
- small, usually about
1-2mm, furcula can move them 5-6 cm, body shape either elongate or globular
- scavengers
- aquatic species found
on the surface of waters (neustonic); most terrestrial, found in moist
soils among humus and other debris
Checklist of the Collembola: http://www.geocities.com/~fransjanssens/
Order Ephemeroptera* - mayflies
- gills on abdomen,
including mid-abdominal segments, often plate-like
- hemimetabolous (egg,
larva and adult); adult short-lived, often just a day or so
- adult with a pre-reproductive
(subimago or dun) stage, which soon again molts into a reproductive adult
(imago or spinner)
- 1 tarsal claw
- usually 3 cerci,
though middle segment may be reduced or absent in some genera
- mostly are primary
consumers, but some are carnivorous
- usually intolerant
of poor water quality
Order Odonata* - dragonflies and damselflies
(c) 1998, Ethan Bright 
(c) Mark O'Brien
- gills as mentioned
below
- hemimetabolous, both
larvae and adult carnivores; adult strong, agile fliers
- larvae with enlarged
lower mouth that can extend outwards to capture prey (gape limited predator)
- two suborders in
Michigan
Suborder
Zygoptera - damselflies
- nymph slender, thorax and abdomen not wider than head
- 3 slender caudal lamella (gills) at end of abdomen
- adults hold wings up
- Common families: Coenagrionidae, Lestidae, Calopterygidae
Suborder
Anisoptera - dragonflies
- nymph robust, thorax and/or abdomen wider than head
- no caudal gills, rather gills contained within rectal chamber in abdomen
- adults hold wing outwards from body
- Common families: Aeshnidae, Cordulegastridae, Macromiidae, Corduliidae,
Libellulidae
More about Odonata:
Detailed list of links: http://www.capecod.net:80/~bnikula/on4.htm
Systematics: http://phylogeny.arizona.edu/tree/eukaryotes/animals/arthropoda/hexapoda/odonata/odonata.html
Order
Plecoptera* - stoneflies
- hemimetabolous, adult
similar to nymph
- with or without gills,
but gills never on middle abdominal segments
- various trophic levels,
scrapers and grazers of algae, shredders, predators
- generally found in
clear, cold streams, often with lots of cobble, usually very intolerant
of poor water quality
- 2 tarsal claws
- 2 cerci
©
Biodidac
Photograph by E.
Dunbar
Photograph
by E.
Dunbar
- hemimetabolous (paurametabolous
- nymph very similar to adult, with gradual change to mature adult stage)
- functional wings
- front half of fore wing hardened
- many hold air supply
in "air bubble" under wing, others use "siphon" to breath air directly
from atmosphere
- most predacious,
some genera in family Corixidae often detritivores, algivores as well as
predators
- have a "beak," piercing-sucking
mouthparts which they dump digestive fluid into prey and suck it back out
- WILL BITE
- 2 tarsal claws
- Common families:
Corixidae, Belostomatidae, Nepidae, Gerridae, Notonectidae
Order
Neuroptera - spongillaflies
- larvae found associated
with freshwater sponges (Spongillidae)
- piercing mouthparts
- holometabolous
- One family: Sisyridae
Order
Megaloptera* - fishflies, dobsonflies, and alderflies
©1997
Thomas Ames Jr.
Sialis larva
: source >>http://140.211.62.101/aquaticinsects/aqinsect.html
- predacious, with
large mandibles, larger individuals will deliver an extremely PAINFUL BITE;
adults do not feed
- holometabolous, only
larvae are aquatic, larval crawls out of water to construct terrestrial
puparium
- sexual dimorphism
in adults, males with large tusks
- multi-segmented antennae
- tarsus with 2 claws
- abdomen ending with
2 prolegs, 2 claws each (dobsonfly) or a single long filament (alderfly)
- eggs laid under alder
leaves (looks like bird poop)
Order
Coleoptera* - beetles
- holometabolous,
various stages aquatic or terrestrial (very diverse)
- larvae may look like
caddisfly or alderfly larvae, but have NO anal claw, and only 1 claw per
tarsus
- multi-segmented antennae
- some larvae with
large mandibles that WILL BITE
- predators (large
dytiscid or hydophilid larvae will feed on large insects, small fish and
tadpoles), but
some are
scrapers (Elmidae, Psephenidae)
- Common families:
Dytiscidae, Hydrophilidae, Elmidae, Psephenidae, Gyrinidae
source
of picture: >>http://www.lcra.org/lands/watershedmanagement/arcbmlis.htm
- holometabolous, egg,
larvae and pupae usually aquatic
- no cerci or chewing
mouthparts in adults like trichopterans
- larvae with 3-6 prolets
ringed with fine hooks on abdominal segments
- one common family
in Michigan in freshwaters - Pyralidae
- holometabolous, egg,
larvae and pupae are aquatic
- adults with only
1 pair of legs, metathorax with club like balancing structure (halteres)
- thorax without segmented
legs
- prolegs, pseudopods,
and creeping welts are frequent structures on larval body
- larvae with almost
no sclerotization
- usually primary consumers,
but some are also detritivores, shredders and predators
- four very common
dipteran families in Michigan freshwaters:
- Family Chironomidae - non-biting midges
- larvae usually white, or clear, but some with hemoglobin and appear red
(blood midges)
- head capsule scleritized, body soft
- thoracic and anal prolegs
- adult looks similar to mosquito
- most speciose family of aquatic insects (20,000 species?), often most
numerous single
type of aquatic insects, hence often plays an extremely important role
in food chains
- primary consumers (algae), shredders, detritivores, carnivores
- Family Tipulidae - crane flies
- larvae worm- or maggot-like
- tiny head retracted into thorax
- adults have long wings and legs ("daddy long legs mosquito")
- largest dipteran family, most species are terrestrial but many aquatic
genera
- shredders, carnivores
- Family Simulidae - black flies
- larvae "bulb-shaped" with sclerotized head
- thorax with large proleg
- head with large fans that allow filter-feeding of algae, usually lotic
waters
- adults often require blood meal, can emerge in huge numbers
- associated with some diseases in Africa
- Family Culicidae - mosquitos
- larvae have anal syphon for breathing atmospheric air
- head is distinct from segmented body
- filter feeders
- lentic waters of many types, can occur in high densities, do not do well
in moving waters
- adults often require blood meal, often associated with many diseases
worldwide
