Topics · Department of Entomology and Nematology 352-392-1901 x126 [email protected] Research Area: Biological Control of Aquatic & Terrestrial Weeds Reference: Merritt, R. W.,

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PHC 6937: Water Biology

Aquatic InsectsAquatic InsectsTaxonomy, Ecology & BioControl Case Study

Dr. Jim Cuda, Associate ProfessorDepartment of Entomology and Nematology

352-392-1901 x126 [email protected]

Research Area: Biological Control of Aquatic & Terrestrial Weeds

Reference: Merritt, R. W., K. W. Cummins, and M.B. Berg (eds.). 2007.An Introduction to the Aquatic Insects of North America, 4th edition.

Topics

• Introduction• Overview of Aquatic Insect Taxa• Habitat Classification and Terminology• Example of Trophic Organization and Function− Hydrilla BioControl Case Study

• Questions?

Topics

• Introduction• Overview of Aquatic Insect Taxa• Habitat Classification and Terminology• Break• Example of Trophic Organization and

Function− Hydrilla BioControl Case Study

• Questions?

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May Flies Stop Motorists

“Lawrence Rutz stops his truck on the westchannel bridge at LaCrosse, WI, yesterdayto clear mayflies from the front of thevehicle. The insects got so thick theyobstructed the view of the driver, cloggedradiators, and made the roadway of thebridge slippery.”

Chicago Daily NewsJuly 8, 1946

Why Study Aquatic InsectCommunities?

• Basic research on population dynamics– Predator-prey interactions– Trophic relationships– Competition studies

• Applied research (Pest Management)– Control of human and animal pests

(e.g., mosquitoes, black flies, horse flies)– Pollution studies

(e.g., mayfly naiads, moth fly larvae)– Biological control of aquatic weeds

(e.g., alligatorweed, water hyacinth, Hydrilla, andHygrophila)

Life History Adaptations for AquaticExistence

• Osmoregulation–Wax layer–Excretion

• Gas exchange–Atmosphere–Plant breathers–Temporary & Permanent Air Stores–Tracheal Gills–Oxygen transport (adults)–Hemoglobin

• Temperature–Thermal death 30 to 40o C

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Topics



• Questions?

Higher Classification Scheme• Phylum Arthropoda – Class Insecta (Insects)

– Subclass Apterygota (w/o Wings)• Order Collembola (Springtails)

– Subclass Pterygota (w/ Wings)• Infraclass Paleoptera (Wings cannot twist)

– Order Ephemeroptera * (Mayflies)– Order Odonata * (Dragonflies & Damselflies)

• Infraclass Neoptera (Wings can twist at base)– Division Exopterygota (Wings develop ext.)

• Order Pleocoptera *(Stoneflies)• Order Hemiptera (True Bugs & Hoppers)

Classification Scheme (cont’d)– Subclass Pterygota

• Infraclass Neoptera– Division Endopterygota (Wings develop int.)

• Order Neuroptera (Dobsonflies, etc.)• Order Trichoptera * (Caddisflies)• Order Lepidoptera (Moths)• Order Coleoptera (Beetles)• Order Hymenoptera (Wasps)• Order Diptera (Moth flies, Mosquitoes,

Midges)

* Entirely aquatic

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Order Collembola- Springtails• Small Size• Antennae Short• Simple Eyes• Presence of Forked

Abdominal Appendage• Chewing/Stylet Mouthparts• Detrivores• Simple Metamorphosis

– Immatures and Adults Live inSame Habitat

– Primitively Wingless

Photo Credit: S. Hopkin

www.abdn.ac.uk/ rhynie/collembolan.htm

Order Ephemeroptera- Mayflies• Small to Medium Size• Antennae Bristle-like• 2 to 3 Thread-like Tails• Nymphs (Naiads) w/

Abdominal Gills• Wings Triangular &

Held Upright at Rest• Chewing Mouthparts• Detrivores• Simple Metamorphosis

– Molt as Winged AdultsPhoto Credit: G. Firebaugh

Order Odonata- Dragon- & Damselflies• Medium to Large Size• Large Compound Eyes• Antennae Bristle-like• Chewing Mouthparts• Nymphs (Naiads) w/

Abdominal or RectalGills

• Wings Elongate & HeldDorsally or Laterally atRest

• Predaceous• Simple Metamorphosis Photo Credit: P. Myers

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Order Plecoptera- Stoneflies• Small to Medium Size• Antennae Long, Slender• Chewing Mouthparts• Membranous Wings

Folded Flat Over Body• Body Soft, Flattened• Cerci Present• Omnivores• Branched Gills on Thorax• Simple Metamorphosis Photo Credit: S. Houston

& T. Murray

Order Hemiptera- True Bugs• Small to Large Size• Antennae Bristle-like• Piercing Mouthparts• Wings Membranous at

Apex• Body Slender to Oval• Raptorial Front Legs• Predaceous• Breathing Tube or Air

Bubble• Simple Metamorphosis Photo Credit: www.cals.ncsu.edu

Giant Water Bug Outbreak

The invasion of the giant water bugThe invasion of the giant water bugCustomers stomp and cringe as swarms cover a Pasco shoppingCustomers stomp and cringe as swarms cover a Pasco shoppingplaza.plaza.They're huge, creepy - and crunchy in sauce.They're huge, creepy - and crunchy in sauce.

By ALEX LEARY, Times Staff WriterBy ALEX LEARY, Times Staff Writer© St. Petersburg Times© St. Petersburg Timespublished June 21, 2003published June 21, 2003

Electric Light Bug, Lethocerus sp.

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Order Neuroptera- Dobsonflies, etc.

• Small to Large Size• Antennae Long, Slender• Chewing Mouthparts• Wings Membranous w/

Numerous Cross Veins– Held Roof-like Over Body

• Lateral Abdominal Gills• Predaceous• Complete Metamorphosis

Photo Credit: www.cals.ncsu.edu

Order Trichoptera- Caddisflies

• Small to Medium Size• Antennae Long, Slender• Chewing Mouthparts• Wings Hairy, w/ Scales

– Held Roof-like Over Body• Larvae Caterpillar- like

– Construct Cases• Omnivorous• Complete Metamorphosis Photo Credits: J. Hodges & T. Murray

Order Lepidoptera- Moths• Small to Medium Size• Antennae Variable• Sucking (A) /Chewing

Mouthparts (L)• Scales on Wings• Respiration Variable

– Cutaneous, Air Bubble,Tracheal Gills

• Phytophagous• Complete Metamorphosis

Waterlily leafcutter, Synclita obliteralis (Lep.: Crambidae)

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Order Coleoptera- Beetles• Small to Large Size• Antennae Variable• Chewing Mouthparts• Hardened Wings (Elytra)• Respiration Variable

– Plastron, Air Bubble,Abdominal Gills

• Predaceous• Complete Metamorphosis

Photo Credit: S. Boucher

Order Hymenoptera- Wasps• Small in Size• Antennae Long• Chewing Mouthparts• Membranous Wings• Respiration Variable

– Air Bubble, Cutaneous• Parasitic• Complete Metamorphosis

Photo Credit: P. Coon

Order Diptera- Flies• Small to Medium Size• Antennae Variable• Sucking / Chewing

Mouthparts• 1 Pair Membranous

Wings• Respiration Variable

– Cutaneous, Air Tubes• Omnivorous• Complete Metamorphosis

Photo Credit: A. Wild & J. Neuswanger

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Hygrophila Survey 2007

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Coleoptera Lepidoptera Diptera Odonata Hemiptera Trichoptera Collembola

Insect Orders

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Topics



• Questions?

Aquatic Habitat Classification SystemCategory

Rivers• Lotic-erosional• Lotic-depositionalLakes• Lentic-limnetic• Lentic-littoral• Lentic-profundal• Benthos

Description

– running-water riffles– running-water pools

– open water (shallow)– shallow shore area– open water (deep)– sediments

Merritt & Cummins (1996)

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Lentic (Lake) Communities & Zones• Surface Film

– Pleuston- Surface Dwelling Organisms• Limnetic Zone- Open Water to Light• Penetration Limit

- Nekton- Free Swimming Organisms- Plankton- Free Floating Organisms

• Littoral Zone- Shallow Region Where• Plants Grow

– Diverse Assemblage of Insects• Profundal Zone- Low Light, No Plant Growth → Low O2 Levels• Benthos- Sediment

Lentic Communities and Zones ( Merritt & Cummins 1996 )

Benthos

PleustonWATER SURFACE

LIGHT COMPENSATION POINT

LITTORAL LIMNETIC

PROFUNDAL

PlanktonNekton

Modes of Existence in Aquatic Habitats Category

• Pleuston

• Limnetic / Littoral– Divers– Swimmers– Clingers– Sprawlers– Climbers

• Benthos– Burrowers

Examples

– Hemiptera: Gerridae– Diptera: Culicidae

– Coleoptera: Dytiscidae– Ephemeroptera: Siphlonuridae– Trichoptera: Hydropsychidae– Odonata: Libellulidae– Odonata: Aeshnidae

– Diptera: ChironomidaeMerritt & Cummins (1996)

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Functional Feeding Groups Category

• Shredders• Collectors• Scrapers• Piercers• Predators• Parasitoids

Food Type

– Living plant tissue– Decomposing FPOM– Periphyton and CPOM– Algae and plant cell fluids– Animal tissue (multiple prey)– Animal tissue (single prey)

Merritt & Cummins (1996)

Topics


Function-− Hydrilla BioControl Case Study

• Questions?

Topics


Function-− Hydrilla BioControl Case Study

• Questions?

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• Rooted submersed aquatic plant• Tropical and subtropical distribution

– Native range- Africa, Asia, Australia• Monotypic stands

– Displace native spp.– Reduce biodiversity

• Dense surface mats– Impede navigation– Interfere with flood control

Hydrilla verticillata (L.f.) Royle

http://www.dep.state.fl.us/lands/invaspec/index.htm

Why is Hydrilla Invasive?Enemy Escape HypothesisEnemy Escape Hypothesis

• Native Specialist Enemies ControlAbundance and Distribution of Native Plants

• Escape from Specialist Enemies is KeyContributor to Exotic Plant Success

• Enemy Escape Benefits Exotics BecauseThey Gain a Competitive Advantage OverNative Plants as a Result of Being Liberatedfrom Their Pests

Williams, J. R. 1954. The biological control of weeds. - In: Report ofWilliams, J. R. 1954. The biological control of weeds. - In: Report ofthe Sixth Commonwealth Entomological Congress, London, UK, pp.the Sixth Commonwealth Entomological Congress, London, UK, pp.95-98.95-98.

Wakulla Springs, April 2002

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HYDRILLA TROPHIC ORGANIZATION AND FUNCTION

Light

Photosynthesis

Hydrilla(Non-nativeProducer)

CPOM

Benthic InorganicNutrients

Terrestrial Organic Nutrients

CPOM DOM

FPOMChironomids

(Scrapers)(Collectors)

Microbes

Microbes

Microbes

Microbes


Light

Photosynthesis


Chironomids(Scrapers)

(Collectors)

Odonate naiads(Predators)

Feces



CPOM DOM

FPOMChironomids


Microbes

Microbes

Microbes


Light

Photosynthesis


Hydrellia spp.(Shredders)


Feces



CPOM DOM

FPOMChironomids


Microbes

Microbes

Microbes Classical BioControlAgents

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Hydrellia pakistanae Deonier(Diptera: Ephydridae)

• Imported from India• Released in 1987 by USDA• Larvae – leaf miners• Life cycle- ~ 21 days• Established Southeast US• Ineffective ? USACOEAdult

Larva Pupa


Light

Photosynthesis




Feces



CPOM DOM

FPOMChironomids


Microbes

Microbes

Microbes

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DAMSELFLY NAIADS

Predator-Prey Cycles Predator-Prey Cycles CAIPS, 1995-1997CAIPS, 1995-1997

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Predator-Prey Cycles Predator-Prey Cycles CAIPS, 1995-1997CAIPS, 1995-1997

Results of Autoradiography Experiment

X / Y = Organisms labelled with 35 S / organisms collected

a

a


Light

Photosynthesis




Trichopria(Parasitoid)

Feces



CPOM DOM

FPOMChironomids


Microbes

Microbes

Microbes

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Trichopria columbiana (Ashmead)(Hymenoptera: Diapriidae)

• Pupal endoparasitoid

• Parthenogenetic- Wolbachia induced ?

• Females semi-aquatic• Capture air under wings

Factors Impacting Factors Impacting HydrelliaHydrellia

•• ParasitismParasitism–– SignificantSignificant–– Upwards of 30%Upwards of 30%

•• Late in growingLate in growing season season

–– PupalPupal parasitoid parasitoidbehaviorbehavior

•• Selects wide rangeSelects wide range•• Stage chosen =Stage chosen = most successful most successful

TRICHOPRIA WASP

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T.columbiana

TEMP (MAX)

Surface Temp. & Population CurvesSurface Temp. & Population CurvesCAIPS, 1995-1997CAIPS, 1995-1997

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Light

Photosynthesis



Feces



CPOM DOM

FPOMChironomids


Microbes

Microbes

Microbes

Cricotopus

Shredders

Parapoynx

Hydrilla Attacking MothParapoynx diminutalis Snellen

• Adventive spp. from Asia• Collected in 1976,

Ft. Lauderdale Area• Principle host plant is

hydrilla• Introduced via aquarium

trade• Damage to hydrilla

minimal and sporadic• Poor biocontrol agent


Light

Photosynthesis



Feces



CPOM DOM

FPOMChironomids


Microbes

Microbes

Microbes

Cricotopus

Shredders

Parapoynx

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Hydrilla Attacking MidgeCricotopus lebetis Sublette

• Identified Dec 1998• Collected in 1959,

Natchitoches, LA• Described 1964• Hydrilla in Louisiana ?

– Natchitoches,1973• Immigrant or native

species????

Life Cycle of Cricotopus lebetis

Hydrilla Growth PatternGlasshouse Tank Experiment, 1998

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TIME (days)

CONTROLC. lebetis

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Block 1: Control Block 1: Treatment

http://plants.http://plants.ifasifas..uflufl..edu/guide/bioconsedu/guide/biocons.html.html

Web Sites

http://plants.ifas.ufl.edu/

http://ipm.ifas.ufl.edu/index.htm

Topics



• Questions?

Documents

Topics · Department of Entomology and Nematology 352-392-1901 x126 [email protected] Research Area: Biological Control of Aquatic & Terrestrial Weeds Reference: Merritt, R. W.,