Term
| Describe Tricoptera and name a few families |
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Definition
- caddisflies
- have anal prolegs with hook
- less visable antennae
- only order that makes cases
- adult wings lay down, very hairy
- Hydropsychidae, brachycentridae, limnephilidae |
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Term
| Describe Coleptera and name a few families |
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Definition
beetles
- egg, larva, pupa, adult
- larva very different from adult
- adults- have hard case on body that does not overlap
- adults have chewing mouthparts
- larva- undeveloped eyes, sometimes have tusks
- elmidae, dytiscidae, gyrinidae (whirligig) |
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Term
| describe megaloptera and name a few families |
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Definition
- alder flies, dobsonflies
- mouth has large, chewing pinchers (predacious)
- abdomen has strand-like appendages extending from each side
- three pairs of segmented legs on middle section of body with tiny pinchers at the end of each
- each segment contains filaments for respiration
- abdomen ends with two elongated appendages or prolegs
- only two families in the world (sialidae (alderflies) and corydalidae (dobson flies)) |
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Term
| describe diptera and name a few families |
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Definition
- midges, mosquitoes, gnats, flies
- elongate body
-segmented body
- most species rich order (includes chironmidae)
- adults have one pair of wings
- very diverse morphology
- tipulidae, simuliidae, chironomidae |
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Term
| Describe the functional groups of aquatic insects based on behavioral habits |
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Definition
- skaters: water surface (gerridae, striders)
- planktonic: water column migration or those who floar just under the water surface
- divers: use of legs to row down water column (boatmen and backswimmers and diving beetles)
- swimmers: fish like body movements to move between rocks
- clingers: attach to objects and move usings claws/suckers. often flattened (heptageniidae)
- climbers: attach to macrophytes (plants)
- burrowers: live in fine sediments and burrow |
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Term
| Describe the functional feeding groups of aquatic insects |
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Definition
- shredders: herbivores (chew vascular plants) or detrivores (chew CPOM (coarse particulate organic matter)), plecoptera and tricoptera
- scrapers (grazers): herbivores that "scrape" periphyton (water scum on rocks), ephemeroptera, trichoptera
- collectors: detrivores that filer or gather FPOM (fine particulate organic matter)) ephemerptera, tricoptera, diptera
- predators: carnivores that chew prey, pierces that suck fluid, plecoptera, odonata, hemiptera, megaloptera |
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Term
| Explain the river continuum concept in terms of aquatic insect functional feeding groups and each of the following terms :CPOM, FPOM, and DOM |
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Definition
| Upstream import and terrestrial input add course particulate organic matter, fine particulate organic matter, and dissolved organic matter into the stream. The CPOM is consumed and broken down by shredders, whose feces and fragments of the CPOM become FPOM. The CPOM is also leached by micro-organisms, turning it into DOM. The shredders then become prey for vertebrate predators. The scrapers eat diatoms off of rocks, and are consumed by insect predators. Some of the DOM, due to microbial assimilation, becomes FPOM, which is consumed by collectors, the rest of the DOM goes downstream. Their feces and fragments make more FPOM. The collectors are preyed on by insect predators. Some of the FPOM from insect predators goes downstream. |
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Term
| Explain stream drift and give reasons why it occurs |
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Definition
| At around 10-2 at night, a large influx of insects will let go of their substrate and move downstream in the water column. While there is no one explanation for this, some explanations could be to avoid predators, to increase prey availability, to disperse to less crowded areas, and possibly accidental |
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Term
| Explain why aquatic insects are used for biomonitoring of aquatic systems |
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Definition
Often use BMI’s because:
•they live in relatively short stream reaches
•many live for 1+ years
•they show a wide range of tolerances for environmental conditions
•they are easily collected and preserved with simple equipment
•usually diverse with many taxa
•found in many habitat types |
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Term
| Describe how rapid bioassessments are conducted using BMI's |
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Definition
| 100 meter reach of the stream is selected (or some multiple of stream reach). a composite sample is taken from individual spots in the riffles and runs using kicknets, dframe nets or sieve buckets. sorting is done on site, someone identifies the order or family while someone else tallies the results. Usually, a number of samples (like 100) is agreed upon for each person to collect. |
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Term
| Explain how an IBI (index of biological integrity) works to determine the relative health of streams |
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Definition
| Three replicates are done. The total number of taxa, as well as the number of ephemeroptera, plecoptera, and tricoptera taxa and number of clingers are counted in a stream sample (this is average of the three replicates). Number of long lived and intolerant taxa is found (add up all three replicate values for each) percent dominance, percent predators and percent toleant individuals is found (averaged for the three replicates). These values are used to assign the stream a score between 0-50. The closer to 50, the healthier the stream. |
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