Coleoptera
~ 5,000 aquatic beetles worldwide
Most live in substrate:
• Adults usually leave water temporarily dispersal.
– One time - Elmidae (riffle beetles)
– Several times - Dytiscidae, Hydrophilidae
Respiration?
• 1. Self-contained air reserves
(Dytiscidae - diving beetle)
• 2. Transcuticular respiration (gills in
larvae)
• 3. Plastron respiration (adult Dryopidae)
• 4. Piercing plant tissues (larval
Chrysomelidae) Slender antennae
Hind coxae extend posteriorly
divide first abdominal
segment
Swimming hairs on legs
Respiration?
• 1. Self-contained air reserves
(Dytiscids)
• 2. Transcuticular respiration (gills in
larvae)
• 3. Plastron respiration (adult Dryopidae)
• 4. Piercing plant tissues (larval
Chrysomelidae)
Respiration?
• 1. Self-contained air reserves
(Dytiscids)
• 2. Transcuticular respiration (gills in
larvae)
• 3. Plastron respiration (adult Dryopidae)
• 4. Piercing plant tissues (larval
Long toed water beetles
Chrysomelidae)
Woolly hairs except last
abdominal segment
Short antennae
Respiration?
• 1. Self-contained air reserves
(Dytiscids)
• 2. Transcuticular respiration (gills in
larvae)
• 3. Plastron respiration (adult Dryopidae)
• 4. Piercing plant tissues (larval
Chrysomelidae)
Varied life histories
• Some larvae occur year round, adults
for short period (Psephenidae)
Water pennies
Larvae are aquatic, adults terrestrial
Varied life histories
• Others occur as larvae and adults year
round – Elmidae = riffle beetles
Long antennae
5-segmented tarsi
Crawl on bottom - do not swim
= no swimming hairs on hind legs
5-6 abdominal segments
Varied life histories
• Others have long adult; larva only
around a few weeks - Hydrophilidae
– Water scavenger beetles
Adult
3 segmented club antennae
5 segmented tarsi
Larvae
Large mandibles
4 segmented legs
Adults = terrestrial!
Scirtidae = marsh beetles
• Small (5 - 15 mm)
• Larvae have long antennae
• 4-segmented legs, single claw
Beetle pupae are mostly
terrestrial
• Under stones or logs
• Few marine beetles - substrate dwellers
Larval morphology = diverse
• Sclerotized head capsule
– Mandibles, maxillae, labium
• Gill-like appendages in some (Gyrinidae
= whirligig beetles)
Coleoptera
Coleoptera
Coleoptera
Coleoptera
The key
2 compound eyes
that appear to be
divided =
Gyrinidae, whirligig
beetles
Eyes not divided, hind coxae
divided into plates that cover
abdominal segments 1-2, or 3
• Haliplidae, crawling water
beetles
Hind coxae not expanded into
plates, divide abdominal
segment 1
• Dytiscidae,
predaceous
diving beetles
Hind coxae not dividing
abdominal segment 1,
antennae clubbed with cuplike
segment at base
• Hydrophilidae, water
scavenger beetles
Antennae short with comb-like
club, body length 5-6.5 mm
• Dryopidae, long-toed
water beetles
Antennae w/o comblike club,
body length < 4.5 mm
Elmidae, riffle beetles