Aquatic Insectsor Aquatic

Macroinvertebrates

Classification

• Kingdom Animalia (Animals)

• Phylum Arthropoda (Arthropods) • Class Insecta (Insects)

What it Means

• "Aquatic" means water

• "macro" means big (or big enough for us to see without using a microscope)

• "invertebrate" means without a backbone

Importance of

• Provide food for other insects, birds, fish, and mammals

• Help scientists determine species biodiversity which can aid in determining water quality

History

• Insects first showed up in our rock record during the late Silurian Period ~ 420-425 mya

• These included terrestrial myriapods of which millipedes are part of

• Aquatic species, such as nymphs and adult stoneflies and mayflies have also found then

Named By the Way They Eat

• Shredders- are herbivores and/or detritivores that specialize in larger items which are broken into smaller pieces

• Collectors- are herbivores and/or detritivores that gather already broken down food items

• Scrapers- “ “ that eat very small particles, often algae that are attached to surfaces

• Predators- are carnivores that eat live animals, either whole, in part, or by piercing them and sucking out their fluids

MayfliesOrder- Ephemeroptera

• Name of the order comes from either the ephemeral quality of the adult insects or the name Ephemeroptera is derived from the Greek "ephemera" meaning short-lived, and "ptera" meaning wings.

Unique in the Insect World

• Only insect to go through two winged stages• Others insects only molt once• The two adult or winged stages are:-Subimagoes (duns)-Imagoes (spinners)

Life Cycle

http://www.delawareriverguide.net/insects/mayflycyc.html

Incomplete Metamorphosis• 1. Egg matures into a nymph. • 2. The nymph lives on the bottom growing in stages called

instars* until it matures. • 3. The mature nymph (emerger) swims to the surface. • 4. Sheds it's husk becoming a dun, (subimago) and floats along

the surface until it's wings are dry enough to take flight. In the insect world this subimago stage is unique to Mayflies. That is insects that are fully winged before the adult stage.

• 5. The dun flies into the bushes, or trees along the river bank, where it sheds it's skin becoming an adult, (spinner), (imago).

• 6. The spinner leaves the trees, or bushes to begin the mating swarm.

• 7. The female spinner dips her eggs on the waters surface, and they fall to the streams bottom.

• 8. After mating both male, and female spinners fall to the waters surface, and die.

http://www.delawareriverguide.net/insects/mayflycyc.html

Spinners

• ”Males appear first beginning the mating ritual high above the water. They flutter and dance in an effort to attract a female. Soon females appear, diving into the swarm to pick out a mate. As mating progresses the swarm falls closer, and closer to the waters surface. Fluttering through the air males hold females in place with their claspers. With the mating process complete females, leave the males, and begin depositing their eggs on the water. Exhausted, males begin falling into the water. They struggle to stay alive for a time, holding their wings upright, but soon fall flat on surface. After depositing their eggs females soon follow.”

http://www.delawareriverguide.net/insects/mayflycyc.html

Nymph Body Parts

http://mrffs.com/atlanticsalmontrinsects.html

http:

//w

ww

.del

awar

eriv

ergu

ide.

net/

inse

cts/

nym

phid

.htm

l

Clingers- Family Heptageniidae

http://www.aquaticinsect.net/portfolio/mayfly-larvae-ephemeroptera/

Swimmers- Family Baetidae

Burrowers- Family Ephemeridae

Adult Mayfly Body Parts

http://www.ces.iisc.ernet.in/biodiversity/sahyadri_enews/newsletter/issue35/article/index.htm

Caddisflies- Order Trichoptera

• Also known as sedges, especially in England• There are over 1200 species in North America

and that is double that of mayflies• Experience Complete Metamorphosis- Egg larva pupa adult

Life Cycle

• Have ~ a one-year life cycle• Go through 5 instar* stages* Instar- shedding of exoskeleton as invertebrate grows

Complete Metamorphism(Holometaboly)

• Evolution of this adaptation occurred during the Upper Carboniferous Period ~ 290 mya

• With the evolution of the pupal stage, organisms could focus energy energy on the development of adult organs and structures whereas during incomplete metamorphism, nymphs have to spend energy on foraging for food

Stages of Development

http://www.delawareriverguide.net/insects/caddisflycyc.html

1. Egg matures into larva. 2. The larva lives on the bottom growing in stages called instars* (typically five) until it matures. Some types of caddis like Rhyacophila are free living, and don't build cases until the pupal stage, other free living caddis like Hydropsychidae that build retreats near their catch nets. Others build portable cases, and abandon them, building new ones as they grow. A. A free living caddis. B. Caddis larva with a portable case. C. A free living caddis in it's retreat near it's catch net. 3. The larva then either seals it's case, or retreat, or builds a case where it pupates (undergoes metamorphosis). 4. The mature pupa cuts itself free from it's case and swims or crawls to the surface, where it sheds it's pupal membrane, and emerges as an adult. 5. The adult caddis flies into the trees, and bushes along the stream where it stays for two or three days. Mating takes place either on the ground or in the trees, and vegetation along the stream. Mating gets underway as adults begin swarming in, and around a tree, or bush. This activity signals the beginning of the mating swarm, with the adult caddis using the bush, or tree as a landmark, or focal point to gather.

6. Females fly off to deposit their eggs. 7. Methods of egg laying (ovipositing). D. On bushes and trees overhanging the stream, where rain will wash the eggs into the water. E. On the stream surface. F. Above the stream surface. G. Swimming or crawling to the stream bottom. 8. Unlike Mayflies after ovipositing adult Caddisflies don't die right away, but fly off to live for a varying length of time.

Larvae

Free-Living- Genus Rhyacophila (Green Rock Worm)

Body and wing colors will darken when the insect is ready to lay eggs.

Case Builders- Genus Glossosoma

Net Spinners- family Hydropsychidae

Body Parts

Adult

Stoneflies- Order Plecoptera

• Greek plektos 'twisted' + pteron 'wing'; refers to the folded posterior region of the resting hind wing

http://bugguide.net/node/view/76

Importance Of

• “nymphs of most species develop in cool, well-oxygenated water and do not tolerate pollution; therefore, their presence is an indicator of good water quality, and their absence in areas where they previously occurred may indicate pollution”

Emergence/Hatching Season

• “adults of most species emerge during late spring and summer; however, the so-called "winter" stoneflies emerge and reproduce during the fall and coldest parts of the winter”

What they eat

• “nymphs feed on algae, diatoms, mosses, and immature aquatic invertebrates, including mayflies and midges; most spring and summer adults do not feed, and are nocturnal; winter stoneflies are day-flying, and feed on blue-green algae and foliage”

Life Cycle Summary

• “females deposit several egg masses, which together may total more than 1,000 eggs, by flying over water or occasionally by crawling up to the water; some nymphs are known to molt 12-36 times, and require one to three years to mature; full-grown nymphs leave the water, cling to shoreline vegetation and debris, and molt into the adult stage.”

http://bugguide.net/node/view/76

Life Cycle

://http://www.delawareriverguide.net/insects/stoneflycyc.html

Life Cycle• ”1. Egg matures into a nymph. • 2. The nymph lives on the bottom growing in stages called instars*

until it matures. Depending on species maturity takes from three months to three years.

• 3. As the nymph nears maturity it migrates to the edge of the stream. • 4. The nymph crawls out of the water, and up into the streamside

vegetation, usually at night. Males usually emerge prior to the females. Here in the streamside vegetation the final instar is completed as the stonefly sheds it's husk becoming an adult. The adult stoneflies life span varies from a day or two to a few weeks.

• 5. Adult Stoneflies mate either within the vegetation or on the ground.

• 6. Females fly out over the stream to deposit eggs. • 7. Female Stoneflies drop their egg sack into the water either by

dropping it from above the stream surface, dipping their abdomen into the water's surface, while flying above it, or crawling across it. Some species crawl down the bank and deposit their eggs under the water.

• 8. The eggs drop to the stream bottom. “

“Golden Stones”

Golden Stonefly

http://www.flyfishusa.com/flies/golden-stone.htm

“Yellow Sallies”

Little Yellow Stoneflies(Yellow Sallies)

http://www.flyfishusa.com/flies/little-stones.htm

Brown Stonefly

Imitation is key

http://troutunderground.com/category/tennessee/

http://www.danica.com/flytier/dbeamish/golden_stonefly_nymph_dark.htm

“True Flies”- Order Diptera

• Midges are considered “true flies” • The name Diptera is derived from the Greek

words "di" meaning two and "ptera" meaning wings

Midges- Family Chironomidae or Ceratopogonidae

• Chironomidae- “Non-biting midges”• do not bite, suck blood, or carry disease -ex. Chrominids

• Ceratopogonidae-“Biting midges”• Pierce skin, suck blood, and can carry disease-ex.- “no see-ums” and “sand flies”

Extremely Important Insects

• Find them present in water and in air at all times of the year

• Can tolerate some of the poorest water conditions

Biting Midge

http://en.wikipedia.org/wiki/File:BitingMidge.jpg

Non-biting Midge

Chrominoid Larvae and Pupae

Emergence into Adult

Life Cycle

Larva

http:

//w

ww

.big

horn

flyfis

hing

.com

Life Cycle Explained

• http://www.lakecountyfl.gov/pdfs/Public_Works/mosquito_and_aquatic_plants/aquatic_midges.pdf

Works Cited

• Pictures- http://biofreshblog.com/2011/05/18/why-stream-mayflies-can-reproduce-without-males-but-remain-bisexual/ephemerella_dorothea_mayfly_dun_1/