VL 1

Question 1

Why are insects important?

Answer 1

Pollination
Food source
Large biomass
Disease vector
Biocontrol
Decomposition
Pests
Culture
Honey
Protein
Wax
Silk

Question 2

What is insect ecology

Answer 2

Study of how insects, individually or as a community, interact with the surrounding biotic (plants, animals, fungi etc.) and abiotic (light, temperature, atmosphere) environment

Question 3

How many of all described species are insects?

Answer 3

50%

Question 4

What is an insect?

Answer 4

Body consists of Head, Thorax and Abdomen

1 pair of antennae

3 pairs of legs

Chitinous exoskeleton

Usually has wings

Question 5

Advantageous morphology / life history

Answer 5

Flight:
- spread within and between environments - exploit new niches
- escape from predators

Reproductive rate:
- fast generation time
- large numbers of offspring
- more likely to get new mutations

Small size:
- muscles require less energy/oxygen
- access to more environments / niches

Chitinous exoskeleton:
- Defence and shock absorption
- waterproof

Question 6

Wide diet breadth

Answer 6

Herbivoure
Carnivore
Parasite
Detrivore
Necrophage
Cophrophage

Question 7

Complex adaptations

Answer 7

Farming
Building
Mimicry
Toxic defenses
Spraying acid
Complex sensory systems
Varying life cycles

Question 8

Complete metamorphosis

Answer 8

Holometabolous
Egg -> Larvae -> Pupa -> Adult

Insect transforms into a different morphology
- 85% of insects
- can specialize in different stages
- can go dormant in unfavourable conditions

Question 9

Incomplete metamorphosis

Answer 9

Hemimetabolous
Egg -> Young nymph -> Later nymph -> Adult

Insect molts when too large for exoskeleton but looks the same

• go through sevral ‘nymph’ stages
• can eat constantly
• vulnerable and soft after molting

Question 10

Diapause

Answer 10

complete pause in development / reproduction, at any growth stage

Diapause is triggered by hormones, usually in response to change in day length and is broken by: more light, change in temperature or wetting due to rainfall

It can allow insects to survive environmental conditions, or travel, that they otherwise would not - ie. Aedes mosquitoes and Monarch butterflies

Question 11

Ecosystem

Answer 11

biological community of interacting organisms and their physical environment

Question 12

Ecosystem services

Answer 12

key interactions that have a major impact on the ecosystem or without which ecosystem function would break down

Question 13

3 broad categories of ecosystem services

Answer 13

Nutrient cycling
Damage and Disease
Support

Question 14

Ecosystem service: Nutrient cycling

Answer 14

Food chain:
Insect herbivores convert plant and algal biomass -> animal biomass
Insects are the an important food source for animals, birds, reptiles, humans etc. moving energy up the food chain

Decomposition:
Insects feed on decaying plant and tree matter (detritovore) or animal corpses or feces (necrophage/coprophage) and play a strong role in recycling energy and nutrients

Question 15

Detrivores

Answer 15

Chew up leaves or bore into dying trees -> speed up bacterial / fungal colonisation

Question 16

Decomposers

Answer 16

Accelerate corpse decomposition through colonization with flies, beetles etc. carry off or invade animal feces

Question 17

Ecosystem services: Support

Answer 17

Maintenance of plant communities:
Insects regulate plant and tree populations through herbivory, preventing overpopulation and allowing new growth, and are involved in both pollination and seed dispersal

Pollination:
pollination by insects is essential for 35% of global fruit and seed production. The economic value of pollination worldwide is estimated to be over 153 billion Euros

Insects aerate soil by moving through it, allowing for water movement and replenish the nutrients in it

Question 18

Ecosystem services: Damage and disease

Answer 18

Extreme herbivory / predation: insects can have devastating effects on diversity and numbers of other organisms, especially in the case of extreme or invasive species. They can cause local extinctions, or a shift in what species are numerous in an ecosystem

Disease vectors of plants, animals and humans: insects are critical carriers of many pathogens which affect health and numbers of important species

Question 19

Keystone species

Answer 19

Keystone species have an effect on other species / environment disproportionate to their numbers

Bsp.
Bees: Responsible for pollinating 250’000 plant species, most of which would not be pollinated enough if they were absent

Ants: Have symbiotic relationships with multiple other organisms, and are predators suppressing other species of harmful arthropod

Question 20

Why do insects contribute so heavily to ecosystem services?

Answer 20

Insects are critical to all stages of ecological functions partially due to:

Diversity - many different traits / habitats / ecological niches

High abundance (impact due to sheer numbers)