Transcript SO-2015-Entomology-Orthoptera

Orthoptera:
(Grasshoppers and Crickets)
• Orthopterans all tend to have
several traits
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Enlarged hind legs
Big compound eyes (usually)
Large pronotum
If winged,
• forewings are thin and leathery
• Hind wings are broad and
membranous
• Usually have two cerci
• Females often have large protruding
ovipositor
• Generally are herbivorous
• Males often ‘chirp’ but in
different ways
Tetrigidae: Pygmy Grasshoppers
• Very recognizable
• Small (3/4th inch)
• Pronotum extends backward
• Otherwise look like
‘Grasshoppers’
• Unusual in that they may
overwinter as adults
• Eat algae, organic matter
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These ARE ‘grasshoppers’
Usually long forewings
Short antennae, often thicker
Have tympana
Pronotum does NOT extend
backwards
• Big pest for agriculture
• Produce low buzzing sound by
rubbing wings together
Acrididae: ‘Short horned’ grasshoppers
• Locusts are specific type of grasshoppers What
• On a year with lots of plants, grasshoppers multiply
• Next year, there are too many grasshoppers
• When crowded together, females hormones change
• Next generation are bigger, and migrate
• Eventually, when population spreads out again,
grasshoppers return to normal
is a locust???
Tettigoniidae: Katydids,
long horned
Grasshoppers
• Very long and slender antennae (1:1)
• Have tympana on foreleg tibia
• Fairly large, katydids are usually green
• There are a few carnivores in this
group
• Most eat leaves though
• Tend to have long forewings
Mormon cricket
Gryllacrididae: Camel Crickets
• Hump backed
• Tan or grey
• Long, threadlike antennae (1:1)
• Do not produce sound
• Do not usually have tympana
• Usually wingless
Jerusalem cricket
Gryllidae: Crickets, tree crickets
• Somewhat short/squat
• Long tapering antennae (1:2)
• Conspicuous cerci
• Shorter forewings
• Tympana on forelegs
• Tree crickets are small
• Green
• Small heads
• Crickets that specialize in
burrowing
• Have enlarged digging forelegs
• Forewings cover half abdomen
• Hind wings are longer
• Feed on plant roots
• Have very large rounded
pronotum
Gryllotalpidae: Mole crickets