AQUATIC COLEOPTERA The Beetles

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AQUATIC COLEOPTERA The Beetles

• CHAPTER 20

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COLEOPTERA CHARACTERISTICS

• HOLOMETABOLOUS
• CHEWING MOUTHPARTS
• MANY TERRESTRIAL FAMILIES, ONLY 12 AQUATICS IN
  THIS AREA
• ADULT FRONT WINGS ELYTRA
• ADULT FOREWINGS MEET IN STRAIGHT LINE OVER
  ABDOMEN
• HINDWINGS FOLDED UNDER FOREWINGS

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COLEOPTERA CHARACTERISTICS

• ADULT ANTENNAE VARIABLE, SOME CONSPICUOUS, SOME
  HIDDEN CLUBBED OR SLENDER
• LARVAE WITH LEGS PRESENT
• NO LARVAL PROLEGS
• SOME LARVAE WITH LATERAL FILAMENTS OR CAUDAL
  HOOKS
• GILLS PRESENT OR ABSENT

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COLEOPTERA DIVERSITY

• ENORMOUS ORDER WITH PERHAPS 1 MILLION SPECIES
• gt100 NORTH AMERICAN FAMILIES
• 5000 WORLD AQUATIC SPECIES

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FAMILY GYRINIDAE Whirligig Beetles

• Adults with divided eyes (or 4 total)
• Hind and hind legs short, oar-like
• Forelegs long and slender
• Antennae short, hidden, with basal projection
• Elytra short, not covering abdomen tip
• Bodies shiny black
• Produce apple-smell, chemical defense
• Some lotic, some lentic

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GYRINIDAE ADULT
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GYRINIDAE ADULT
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FAMILY GYRINIDAE

• Larvae with 10 pairs of lateral filaments
• Resemble slender hellgrammites
• Have 4 terminal hooks but no prolegs
• Legs with 5 segments and 2 claws
• Common genus Dineutus

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GYRINIDAE LARVA
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FAMILY HALIPLIDAE Crawling Water Beetles

• Adults small, somewhat wedge shaped, most lentic,
  some lotic
• Elytra punctate, often spotted
• Antennae conspicuous, 11 segments
• Hind tarsi with swimming fringe, but not
  flattened
• Hind coxal plates large and quadrate

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HALIPLIDAE ADULT
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HALIPLIDAE ADULT/LARVA
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FAMILY HALIPLIDAE

• Larvae slender bodied with short antennae
• 1 tarsal claw and 5 leg segments
• Often with spiny appearance
• Common genera Peltodytes, Haliplus

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HALIPLIDAE LARVA
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FAMILY DYTISCIDAEPredaceous Diving Beetles

• SIZE VARIABLE, 4-30 MM
• HIND LEGS OAR-LIKE, MID AND FORELEGS TYPICAL,
  most lentic,some lotic
• BODY SOMEWHAT FLATTENED, STREAMLINED
• SCUTELLUM SMALL BUT EXPOSED1ST ABDOMINAL SEGMENT
  DIVIDED BY COXAE
• ANTENNAE SLENDER BUT USUALLY HIDDEN
• SURFACE FOR AIR BUBBLE

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DYTISCIDAE ADULT
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DYTISCIDAE ADULT
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FAMILY DYTISCIDAE

• LARVAE PREDACEOUS
• SHORT ANTENNAE
• 5 LEG SEGMENTS, 2 TARSAL CLAWS
• SOME WITH CERCI/LATERAL PROJECTIONS
• MANDIBLES SICKLE SHAPED, HOLLOW
• Common genera Thermonectes, Cybister

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DYTISCIDAE LARVA
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DYTISCIDAE ADULT/LARVA
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FAMILY NOTERIDAEBurrowing Water Beetles

• Oar-like hind legs with hair fringe
• Convex, oval body in adult lentic
• Scutellum hidden, minute
• Antennae slender, hidden
• Many with hook on end of tibiae
• 1st abdominal segment divided by hind coxae

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NOTERIDAE ADULT/LARVA
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FAMILY NOTERIDAE

• Larvae with 5 leg segments, 2 tarsal claws
• Antennae short
• Legs short, stubby
• No cerci, lateral projections
• Mandibles not sickle shaped
• Common genus Hydrocanthus

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FAMILY HYDROPHILIDAEWater Scavenger Beetles

• Adult body usually oval, convex, some lotic most
  lentic
• Scutellum distinct
• Short clubbed antennae, usually hidden
• Palpi usually long, antennae-like
• Hind legs usually natatorial with hair fringe
• Many with ventral keel and spine

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FAMILY HYDROPHILIDAE
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FAMILY HYDROPHILIDAE
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FAMILY HYDROPHILIDAE

• Adult 1st abdominal segment not divided by coxae
• Larvae with 3-5 leg segments, 1 tarsal claw, legs
  usually short
• Some with cerci, lateral projections
• Antennae short
• 8-10 abdominal segments
• Common genera Tropisternus, Berosus

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FAMILY HYDROPHILIDAE LARVA
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FAMILY PSEPHENIDAEWater Penny Beetles

• Adults terrestrial often near water, larvae
  lotic
• Larvae flattened,elongate oval or circular, head
  covered by thoracic carapace
• Antennae short
• Gills on abdomen or in caudal chamber with
  operculum
• Common genera Psephenus, Ectopria

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FAMILY PSEPHENIDAE
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FAMILY PTILODACTYLIDAEToed-wing Beetles

• Adults terrestrial
• Larvae slender, elongate, cylindrical, lotic
• 4 leg segments, 1 tarsal claw
• Abdomen with ventral gills, or gills on anal
  segment
• Common genus Anchytarsus

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FAMILY PTILODACTYLIDAE
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FAMILY DRYOPIDAELong-toed Riffle Beetles

• Adults aquatic, lotic, larvae terrestrial
• Adults black, sluggish with long slender legs,
  long tarsi and large tarsal claws
• Legs not natatorial
• Antennae hidden, small with comb shaped club
• Common genus Helichus

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FAMILY DRYOPIDAE
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FAMILY ELMIDAE Riffle Beetles

• Adults and larvae aquatic, lotic
• Adults with long slender legs, long tarsi and
  claws
• Legs not natatorial
• Dark colored, some with pale spots
• Antennae variable, some moderately long but no
  comb like club

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FAMILY ELMIDAE
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FAMILY ELMIDAE

• Larvae with short legs, long slender, cylindrical
  bodies
• Abdomen with terminal gill chamber covered with
  operculum
• Tip of abdomen with 2 slender hooks lateral to
  gill chamber
• Common genera Stenelmis, Ancyronyx, Macronychus

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FAMILY ELMIDAE LARVA