Orthopteroid insects

Question 1

what are Orthoptrtoids

Answer 1

• 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)

Question 2

order: Orthoptera

Answer 2

• 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)

Question 3

orthoptera - what are locusts

Answer 3

• refers to multiple species of grasshopper (Acrididae, Orthoptera) that form swarms
• can be solitary or gregarious (swarms)
• Solitary form is just a regular grasshopper

Question 3

orthoptera: locusts - adults

Answer 3

the swarms take flight; can travel hundreds or thousands of miles – completely defoliate everything in their path

Question 4

orthoptera: locusts - nymphs

Answer 4

gregarious forms aggregate in huge swarms, march across landscape devouring plants

Question 5

orthoptera: locusts - What determines which ‘phase’ (form) locusts develop into?

Answer 5

overcrowding

Question 6

orthoptera: locusts - how does overcrowding determine locust form

Answer 6

Chemical (pheromone) and tactile stimulation of overcrowding cause brain to secrete hormones, especially serotonin, that stimulate physiological and behavioral changes of gregarious form

Question 7

orthoptera: locusts - how does overcrowding start

Answer 7

• 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

Question 8

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?

Answer 8

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

Question 9

order: Blattodea

Answer 9

• cockroaches
• have Ootheca

Question 10

Blattodea - define ootheca

Answer 10

• egg cases
• Many species carry them around, provide form of parental care

Question 11

Are termites derived from roaches?

Answer 11

• yes
• Cryptocercus (wood roaches) are sister to Isoptera (the termites)

Question 12

are termites derived from roaches - problem

Answer 12

• if you want to include all of the roaches you have to include termites
• Putting roaches and termites as separate groups is paraphyletic

Question 13

order: Cryptocercus

Answer 13

• wood roaches
• Wingless
• Have parental care, live with offspring
• Have gut microorganisms for digesting cellulose (wood). Same one as termites

Question 14

order: Isoptera

Answer 14

• 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

Question 15

order: Isoptera - social

Answer 15

colony size from hundreds to millions

Question 16

order: Isoptera - polymorphism

Answer 16

• 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

Question 17

order: isoptera - life cycle

Answer 17

• 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)

Question 18

order: isoptera - intricate nests

Answer 18

Nest in wood, mound nests in soil (with ventilation tubes exposed), or built of mud and feces in trees

Question 19

order: Mantodea

Answer 19

• 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

Question 20

order: Phasmatodea

Answer 20

• walking sticks and leaf insects
• Walking sticks here; old world also has leaf insects
• Herbivores
• Wingless
• Best known for their crypsis

Question 21

order: Dermptera

Answer 21

• 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