Why study insects

Question 1

What is an insect?

Answer 1

6-legged arthropod with external mouthparts

Question 2

Why study insects?

Answer 2

• Diversity
• Ecological importance
• Importance to human activity

Question 3

why study insects: diversity - why are insects so successful

Answer 3

• old
• Interactions with plants
• create niches for more diversity
• Small size
• Flight
• Body segmentation
• Metamorphosis

Question 4

why are insects so successful - old

Answer 4

• Longer time to evolve than mammals
• they are among the earliest land animals and thus can fill niches early

Question 5

diversity - interactions with plants

Answer 5

• Plants and insects have co-evolved
• Specialization on specific plant species part = massive number of niches
• Chemical defense arms races between plants and insects drive diversity, ecology
• Pollination enabled rise of angiosperm

Question 6

diversity - small size

Answer 6

Can specialize in a small thing (the bigger the body, the more things required to maintain it)

Question 7

diversity - flight

Answer 7

• Flight evolved a very long time ago
• Flying insects likely drove evolution of flight in other groups: if you can fly, you can prey on insects
• Wings vastly improved mobility, dispersal, and escape

Question 8

flight - what are ancestrally flightless insects

Answer 8

an insect’s ancestors did not have wings and the current lineage do not have wings

Question 9

flight - what are secondarily flightless insects

Answer 9

• an insect does not have wings but its ancestor does have wings
• means that the wings were lost in the lineage

Question 10

diversity - Body segmentation

Answer 10

• Having six legs allows for the front pair to be used without losing the ability to walk
• Wings facilitate mobility, but when the fore pair is hardened, they protect the flight pair and abdomen
• exoskeleton guards against injury but also protects insects from their own toxic secretion

Question 11

diversity - metamorphosis

Answer 11

Immatures and adults do not compete for resources

Question 12

metamorphosis - Most diverse insects are Holometabolous but is this the reason for their diversity?

Answer 12

it is unclear whether the diversity is due to metamorphosis since those insects interact with plants as well

Question 13

why study insects - what are the ecological importance of insects

Answer 13

• Pollination
• Decomposition
• Food web
• Ecological dominance of social insects

Question 14

ecological importance - pollination

Answer 14

• Flowers exist to get the attention of insects
• No insects, no flowering plants

Question 15

ecological importance - decomposition

Answer 15

• Beetles and flies are nature’s cleanup crew
• Termites decompose cellulose

Question 16

ecological importance - food web

Answer 16

• Insects are food for most birds, bats, and many other organisms
• Also, insect herbivory (consumption of plants) structures plant communities

Question 17

ecological importance - Ecological dominance of social insects

Answer 17

• Sociality is perhaps the most striking and sophisticated by insects
• No societies, including those of humans, have such efficiency
• The biomass of ants in the world’s tropical river basins is estimated to be up to 4 times that of vertebrates

Question 18

why study insects - importance to human activity

Answer 18

• agriculture
• ecological destruction
• disease

Question 19

importance to human activity - agricultre

Answer 19

• Crop pests (also forest pests)
• Pollination
• Pest control

Question 20

importance to human activity - ecological destruction

Answer 20

Tiny beetles can destroy forests

Question 21

importance to human activity - disease

Answer 21

Insect vectors of pandemic diseases have killed many times more humans than any predator