Aquatic Ecosystems and the Insect Inhabitants

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Aquatic Ecosystems and the Insect Inhabitants

• Jeffery K. Tomberlin, Ph.D.
• Assistant Professor Extension Specialist
• Texas Cooperative Extension
• Texas AM University

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What are some examples of aquatic systems?
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What are some examples of aquatic systems?

• Lentic (standing) vs. lotic (flowing)
• Excludes brackish and marine habitats???
• Inhabited by benthic invertebrates

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Why Study These Systems?
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Why Study These Systems?

• Biomonitoring examining changes in these
  systems. Primarily achieved by study the
  macroinvertebrates (visible insects)

• Surveillance (looking for changes)
• Compliance (bio-accumulation)
• Human-environment interactions

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Why use the insects?
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Why use the insects?

• Ubiquitous
• Large number of species
• Sedentary (allow for measures over time)
• Long life cycles

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How do we measure them?
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How do we measure them?

• Qualitative
• Taxonomy
• Biotic abiotic features are known to be related
  to insects present
• Known responses to pollutants are known for many
  insects

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What are some disadvantages?
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What are some disadvantages?

• Limited change in some instances

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What are some disadvantages?

• Limited change in some instances
• Quantifying can be difficult
• Need lots of samples
• Natural changes can affect abundance (i.e. rain)

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What are some disadvantages?

• Limited change in some instances
• Quantifying can be difficult
• Need lots of samples
• Natural changes can affect abundance (i.e. rain)
• Analysis can be difficult
• Some groups not known well
• Multiple ways to test (can lead to confusion)

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Many insects live in water?
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Many insects live in water?

• Flies
• Beetles
• Bugs
• Megalopterans
• Etc..

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Why are insects a problem?
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Why are insects a problem?

• Nuisance
• A. Impede travel
• B. Emergence from sewage
• C. Disgusting

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Why are insects a problem?

• Nuisance
• A. Impede travel
• B. Emergence from sewage
• C. Disgusting
• Health
• A. Disease
• B. Allergic reaction
• C. Pain

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Mosquitoes?
-How do they transmit diseases?
-Practically everywhere -Tropics primarily -100
viruses
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Mosquitoes

• Larvae live in water (standing)
• Can enter diapause
• Adult females bite day or night
• Transmit filarial worms, viruses, and protozoa

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Mosquitoes

• -Major problems
• Malaria -300 to 500 million cases annually
• -1 million deaths annually
• -Colonial time
• Yellow Fever -1905 New Orleans
• Dengue Fever -1995 Texas

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Mosquitoes

• -Major problems
• Malaria
• Yellow Fever
• Dengue Fever
• -How do we treat?

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Methods of Control for our problem aquatic
insects?

• Bt dunks

6.00/packet
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Methods of Control for our problem aquatic
insects?

• Bt dunks
• Dumping containers

Or screen buckets
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Methods of Control for our problem aquatic
insects?

• Bt dunks
• Dumping containers
• Community spray project

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Mosquitoes

• Why are they still a problem?

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Mosquitoes

• Why are they still a problem?
• -secondary hosts
• -sexual transmission
• -diapause

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Blackflies?
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Blackflies

• Larvae live in water (running)
• Adult females are blood-feeders
• Distributed anywhere with running water (even
  frozen)
• Day feeders

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What Pathogens are Associated with Blackflies?

• -Black fly fever
• -River blindness (filarial worm) 17 million
  infected
• -Mansonellosis (tropical)
• -Painful bites (asphyxiation)
• -Bovine onchocerciasis (Africa)
• -Leucocytozoonosis (U.S.) similar to malaria

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Sandflies and Tabanids?
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Sandflies and Tabanids

• -Larvae in moist
• substrate
• -Feed on organic matter
• -Adults are day feeders
• -Females need blood

-Larvae are in muddy or wet areas -Razor sharp
mandibles -Adults are day feeders -Females only
on blood
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Sandflies and Tabanids

• Annoyance
• Transmit filarial worms or anthrax
• Common sandfly species develop in tree holes
  (water source)
• Bluetongue (virus)
• Hemorrhagic disease

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Benefits of Aquatic Insects?
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Other Benefits of Aquatic Insects

• Food chain

Start
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Other Benefits of Aquatic Insects

• Food chain

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Other Benefits of Aquatic Insects

• Food chain
• Models/Recreation (fishing)

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Other Benefits of Aquatic Insects

• Food chain
• Models (fishing)
• Art (caddisfly)

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Other Benefits of Aquatic Insects

• Food chain
• Models (fishing)
• Art (caddisfly)

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Other Benefits of Aquatic Insects

• Food chain
• Models (fishing)
• Art (caddisfly)
• Biomonitoring

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Summary

• Aquatic Systems are diverse

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Summary

• Aquatic Systems are diverse
• A. Lentic (not running)

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Summary

• Aquatic Systems are diverse
• A. Lentic (not running)
• B. Lotic (running)

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Summary

• Aquatic Systems are diverse
• A. Lentic (not running)
• B. Lotic (running)
• C. Brackish

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Summary

• Aquatic Systems are diverse
• A. Lentic (not running)
• B. Lotic (running)
• C. Brackish
• D. Marine

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Summary

• Aquatic Systems are diverse
• There are negative aspects

Pollution problems
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Summary

• Aquatic Systems are diverse
• There are negative aspects
• A. Pest insects

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Summary

• Aquatic Systems are diverse
• There are negative aspects
• A. Pest insects
• B. Pathogen transmission

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Summary

• Aquatic Systems are diverse
• There are negative aspects
• A. Pest insects
• B. Pathogen transmission
• Control measures???

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Summary

• Aquatic Systems are diverse
• There are negative aspects
• There are positive aspects

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Summary

• Aquatic Systems are diverse
• There are negative aspects
• There are positive aspects
• A. Recreation

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Summary

• Aquatic Systems are diverse
• There are negative aspects
• There are positive aspects
• A. Recreation
• B. Food chain

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