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PHC 6937: Water Biology Aquatic Insects Taxonomy, Ecology & BioControl Case Study

Dr. Jim Cuda, Associate Professor Department 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?

1 May Flies Stop Motorists

“Lawrence Rutz stops his truck on the west channel bridge at LaCrosse, WI, yesterday to clear mayflies from the front of the vehicle. The insects got so thick they obstructed the view of the driver, clogged radiators, and made the roadway of the bridge slippery.”

Chicago Daily News July 8, 1946

Why Study Aquatic Insect Communities? • 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, and Hygrophila)

Life History Adaptations for Aquatic Existence • 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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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

3 Order Collembola- Springtails • Small Size • Antennae Short • Simple Eyes • Presence of Forked Abdominal Appendage • Chewing/Stylet Mouthparts • Detrivores • Simple Metamorphosis Photo Credit: S. Hopkin – Immatures and Adults Live in Same Habitat – Primitively Wingless

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 Photo Credit: G. Firebaugh – Molt as Winged Adults

Order Odonata- Dragon- & Damselflies • Medium to Large Size • Large Compound Eyes • Antennae Bristle-like • Chewing Mouthparts • Nymphs (Naiads) w/ Abdominal or Rectal Gills • Wings Elongate & Held Dorsally or Laterally at Rest • Predaceous

• Simple Metamorphosis Photo Credit: P. Myers

4 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 bug

Customers stomp and cringe as swarms cover a Pasco shopping plaza. They're huge, creepy - and crunchy in sauce.

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

Electric Light Bug, Lethocerus sp.

5 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)

6 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 Photo Credit: A. Wild & J. Neuswanger • Complete Metamorphosis

7 Hygrophila Survey 2007

10 No. of Specimens 5

0 Coleoptera Lepidoptera Diptera Odonata Hemiptera Trichoptera Collembola Insect Orders

Topics

Aquatic Habitat Classification System Category Description Rivers • Lotic-erosional – running-water riffles • Lotic-depositional – running-water pools Lakes • Lentic-limnetic – open water (shallow) • Lentic-littoral – shallow shore area • Lentic-profundal – open water (deep) • Benthos – sediments

Merritt & Cummins (1996)

8 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 )

Pleuston WATER SURFACE LITTORAL LIMNETIC Plankton Nekton LIGHT COMPENSATION POINT

Benthos PROFUNDAL

Modes of Existence in Aquatic Habitats Category Examples

• Pleuston – Hemiptera: Gerridae – Diptera: Culicidae • Limnetic / Littoral – Divers – Coleoptera: Dytiscidae – Swimmers – Ephemeroptera: Siphlonuridae – Clingers – Trichoptera: Hydropsychidae – Sprawlers – Odonata: Libellulidae – Climbers – Odonata: Aeshnidae • Benthos – Burrowers – Diptera: Chironomidae Merritt & Cummins (1996)

9 Functional Feeding Groups Category Food Type

• Shredders – Living plant tissue • Collectors – Decomposing FPOM • Scrapers – Periphyton and CPOM • Piercers – Algae and plant cell fluids • Predators – Animal tissue (multiple prey) • Parasitoids – Animal tissue (single prey)

Merritt & Cummins (1996)

Topics

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

Topics

10 Hydrilla verticillata (L.f.) Royle • 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 http://www.dep.state.fl.us/lands/invaspec/index.htm

Why is Hydrilla Invasive?

Enemy Escape Hypothesis • Native Specialist Enemies Control Abundance and Distribution of Native Plants

• Escape from Specialist Enemies is Key Contributor to Exotic Plant Success

• Enemy Escape Benefits Exotics Because They Gain a Competitive Advantage Over Native Plants as a Result of Being Liberated from Their Pests

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

Wakulla Springs, April 2002

11 HYDRILLA TROPHIC ORGANIZATION AND FUNCTION

Benthic Terrestrial Organic Nutrients Inorganic Light Nutrients

Microbes Photosynthesis CPOM DOM

CPOM Hydrilla Microbes (Non-native Producer) Chironomids (Scrapers) FPOM (Collectors)

Microbes

HYDRILLA TROPHIC ORGANIZATION AND FUNCTION

Benthic Terrestrial Organic Nutrients Inorganic Light Nutrients

Microbes Photosynthesis CPOM DOM

Feces Hydrilla Microbes (Non-native Producer) Chironomids (Scrapers) FPOM (Collectors) Odonate naiads Chironomids (Predators) (Scrapers) (Collectors)

Microbes

HYDRILLA TROPHIC ORGANIZATION AND FUNCTION

Benthic Terrestrial Organic Nutrients Inorganic Light Nutrients

Microbes Photosynthesis CPOM DOM

Feces Hydrilla Microbes (Non-native Producer) Chironomids (Scrapers) FPOM (Collectors) Odonate naiads Hydrellia spp. (Predators) (Shredders)

Classical BioControl Microbes Agents

12 Hydrellia pakistanae Deonier (Diptera: Ephydridae)

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

Larva Pupa

HYDRILLA TROPHIC ORGANIZATION AND FUNCTION

Benthic Terrestrial Organic Nutrients Inorganic Light Nutrients

Microbes Photosynthesis CPOM DOM

Feces Hydrilla Microbes (Non-native Producer) Chironomids (Scrapers) FPOM (Collectors) Odonate naiads Hydrellia spp. (Predators) (Shredders)

Microbes

Predator-Prey Cycles CAIPS, 1995-1997 ) 2 )

1600 160 2 m

m /

/ . 1400 140 . o o n ( n

1200 120 (

HP LARVAE Y Y T I DAMSELFLY NAIADS T

1000 100 I S S N N

E 800 80 E D

E 600 60 Y A L N 400 40 F A L T E S 200 20 S I M K A A 0 0 D P

. H

6-Jul-95 4-Aug-95 9-Nov-95 24-Jul-96 13-Sep-9512-Oct-95 13-Dec-9529-Jan-9628-Feb-9627-Mar-9629-Apr-9629-May-9625-Jun-96 27-Aug-9625-Sep-9622-Oct-9625-Nov-9628-Jan-97

13 Predator-Prey Cycles

CAIPS, 1995-1997

) 2

) m

m .

1800 300 / o

n (

1600 o

HP LARVAE 250 n Y (

1400

T I

DRAGONFLY NAIADS Y S T

1200 200 I N S

E 1000 N

D 150 E 800

D E

600 100 Y N L F

A 400 T

50 N S

200 O I G K 0 0

A P

D H 6-Jul-95 4-Aug-95 9-Nov-95 24-Jul-96 13-Sep-9512-Oct-95 13-Dec-9529-Jan-9628-Feb-9627-Mar-9629-Apr-9629-May-9625-Jun-96 27-Aug-9625-Sep-9622-Oct-9625-Nov-9628-Jan-97

Results of Autoradiography Experiment

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

HYDRILLA TROPHIC ORGANIZATION AND FUNCTION

Benthic Terrestrial Organic Nutrients Inorganic Light Nutrients

Microbes Photosynthesis CPOM DOM

Feces Hydrilla Microbes (Non-native Producer) Chironomids (Scrapers) FPOM (Collectors) Odonate naiads Hydrellia spp. (Predators) (Shredders)

Microbes Trichopria (Parasitoid)

14 Trichopria columbiana (Ashmead) (Hymenoptera: Diapriidae)

• Pupal endoparasitoid • Parthenogenetic - Wolbachia induced ? • Females semi-aquatic • Capture air under wings

Factors Impacting Hydrellia

TRICHOPRIA WASP • Parasitism – Significant – Upwards of 30% • Late in growing season – Pupal parasitoid behavior • Selects wide range • Stage chosen = most successful

Surface Temp. & Population Curves CAIPS, 1995-1997

900 50 H.pak istanae 800 ODONATA 45 T.columbiana ) 700 40 2 C)

TEMP (MAX) 35 O 600 30 500 25 400 20 300 15 DENSITY ( no./ m 200 10 TEMPERATURE ( 100 5 0 0 Jul- Aug- Oct- Nov- Jan- Mar- Apr- Jun- Jul- Sep- Oct- Dec- 95 95 95 95 96 96 96 96 96 96 96 96

15 HYDRILLA TROPHIC ORGANIZATION AND FUNCTION

Benthic Terrestrial Organic Nutrients Inorganic Light Nutrients

Microbes Photosynthesis

CPOM DOM

Hydrilla Feces Microbes (Non-native Producer) Chironomids (Scrapers) FPOM (Collectors) Cricotopus Odonate naiads Shredders (Predators) Parapoynx Microbes

Hydrilla Attacking Moth Parapoynx 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

HYDRILLA TROPHIC ORGANIZATION AND FUNCTION

Benthic Terrestrial Organic Nutrients Inorganic Light Nutrients

Microbes Photosynthesis

CPOM DOM

Hydrilla Feces Microbes (Non-native Producer) Chironomids (Scrapers) FPOM (Collectors) Cricotopus Odonate naiads Shredders (Predators) Parapoynx Microbes

16 Hydrilla Attacking Midge Cricotopus 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 Pattern Glasshouse Tank Experiment, 1998 ) m c (

0 H

T -10 P

E -20 D

A -30 L L I -40 R CONTROL D -50 C. lebetis Y H -60 0 8 13 35 49 62 68 78 88 97 TIME (days)

17 Block 1: Control Block 1: Treatment

Web Sites

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

http://plants.ifas.ufl.edu/guide/biocons.html

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

Topics