Orthopteroid insects Flashcards
what are Orthoptrtoids
- Incomplete metamorphosis (Hemimetabolous)
- Generalized biting/chewing mouthparts
- Generally, herbivores (but mantids are consummate predators, termites/isoptera are consummate decomposers
- Many have leathery forewings (but not Isoptera, Phasmotodea)
order: Orthoptera
- grasshopper, katydids, and crickets
- Forewings thickened and leathery; hindwings used more for flight
- Generalist herbivores
- Many communicate with sound
- Hind legs often modified for jumping
- Most species solitary; occasionally form feeding swarms that are important pests (migratory locusts)
orthoptera - what are locusts
- refers to multiple species of grasshopper (Acrididae, Orthoptera) that form swarms
- can be solitary or gregarious (swarms)
- Solitary form is just a regular grasshopper
orthoptera: locusts - adults
the swarms take flight; can travel hundreds or thousands of miles – completely defoliate everything in their path
orthoptera: locusts - nymphs
gregarious forms aggregate in huge swarms, march across landscape devouring plants
orthoptera: locusts - What determines which ‘phase’ (form) locusts develop into?
overcrowding
orthoptera: locusts - how does overcrowding determine locust form
Chemical (pheromone) and tactile stimulation of overcrowding cause brain to secrete hormones, especially serotonin, that stimulate physiological and behavioral changes of gregarious form
orthoptera: locusts - how does overcrowding start
- favorable conditions cause population increase that leads to overcrowding, and swarm outbreak
- In other times, the locusts persist in the solitary form in suitable habitat
orrthoptera: locusts - Imagine you could somehow kill every locust in a large swarm. Would there still be swarms in future years? Why or why not?
No, bc locusts have a source population that are solitary until overcrowding so in order to stop swarms you have to eliminate the source population
order: Blattodea
- cockroaches
- have Ootheca
Blattodea - define ootheca
- egg cases
- Many species carry them around, provide form of parental care
Are termites derived from roaches?
- yes
- Cryptocercus (wood roaches) are sister to Isoptera (the termites)
are termites derived from roaches - problem
- if you want to include all of the roaches you have to include termites
- Putting roaches and termites as separate groups is paraphyletic
order: Cryptocercus
- wood roaches
- Wingless
- Have parental care, live with offspring
- Have gut microorganisms for digesting cellulose (wood). Same one as termites
order: Isoptera
- Termites
- Treated as own order, despite being part of Blattodea
- Digest cellulose with aid of microorganisms
- Social
- Polymorphism
- Wings for dispersal, but then dropped
- May build intricate nests
order: Isoptera - social
colony size from hundreds to millions
order: Isoptera - polymorphism
- large queen (egg laying slave?)
- Queen is egg-laying machine, sometimes grotesquely so
- Tergites of the queen don’t touch bc they are so expanded
- Soldiers often have modified heads for defense
order: isoptera - life cycle
- Incomplete metamorphosis
- winged queen disperses and find a mate then drop wings
- after mating, find a nest and queen lays eggs
- eggs develop into nymphs
- nymphs may become soldiers, workers, or a reproductive (get wings and start process all over again)
order: isoptera - intricate nests
Nest in wood, mound nests in soil (with ventilation tubes exposed), or built of mud and feces in trees
order: Mantodea
- praying mantis
- Raptorial forelegs for grasping prey. Ambush predators, excellent eyesight
- Sexual cannibalism in some species/circumstances
- Make papery ootheca glued to plants. Nymphs overwinter there
- Some old-world species brightly colored for crypsis in flowers
order: Phasmatodea
- walking sticks and leaf insects
- Walking sticks here; old world also has leaf insects
- Herbivores
- Wingless
- Best known for their crypsis
order: Dermptera
- earwings
- Short wing covers or wingless
- “Pincers” are modified cerci, used by males to fight each other
- Herbivores or scavengers, harmless to humans
- Female care of egg clutches in subterranean ‘nests’
- Female ‘licks’ eggs continuously during development to prevent fungus from attacking egg
