Insect Success Story and external

Question 1

Describe speciation and radiation?

Answer 1

Speciation: creation of new species

Radiation: movement of populations to new places

Question 2

Coevolution

Answer 2

Adaptations in one partner leads to counter adaptations in another partner. Very common in insects and plants with pollination (mutualism) and herbivory (pests inspire plants to produce toxic defence mechanisms).

Question 3

What are some examples of water saving adaptations that insects have made as a result of Coevolution with plants?

Answer 3

Being terrestrial machines insects have undergone vast adaptations to minimize water loss.

Versatile Chitinous exoskeleton cuticle is water proof, damage resistant and radiation resistant.

• Respiratory and excretory systems minimize water loss.

Question 4

Why is chitin so versatile?

Answer 4

It can be used by organisms to form exoskeletons of almost any shape.

Question 5

Why are insects so successful?**

Answer 5

• From an evolutionary perspective: In a patchy terrestrial world, small size makes them efficient exploiters of available resources.
• Small size also leads to quick regeneration and rapid life cycles where mutations are rapidly selected for allowing insects to adapt to changing environmental conditions. (Wings for instance)
• vast array of species isolating mechanisms (hormonal, behavioural, reproductive) lead to immense potential for speciation and radiation.*
• Coevolution interactions with plants allows for immense adaptive radiationship

Question 6

List the 4 main adaptations that make insect so successful

Answer 6

• Evololution of wings on thorax leading to enormous power of dispersal, forage, and maneuverability to escape predation
• Adaptations to minimize water loss with armored chitinous exoskeleton and improved respiration.
• Modification of food gathering and locomotory appendages
• Evolution of metamorphosis where larva is adapted for rapid growth and adult specialized for dispersal and reproduction. Dormant pupa stage between Larva (eat leaves) and adult (nectar) which are morphologically, ecologically and physiologically different.

Question 7

Why are insects so important

Answer 7

Evolution,
Ecology,
Economics

Question 8

What 2 biological systems drive insect success?

Answer 8

Neurosystem development

Muscular system development

Question 9

What are some sensory evolutionary developments that make insects successful?
What is the most important?

Answer 9

Complex sensory structures, all made of cuticle. Complex brain capable of integrating multiple sensory receptors.

-Photoreceptors, chemosensory antennae, auditory receptors, mechanoreceptors.

Chemoreceptors are by far the most important acting as a molecular sieve in order to detect pheromones. (Mate detection, communication [alarm pheremones, trail following, aggregation pheremone])

Question 10

What differentiates larva from adult insects?

Answer 10

Larva have mouthparts designed for feeding on vegetation and undergo massive growth in biomass.

Adults have mouthparts designed for feeding on nectar and have complex food gathering and locomotory appendages.

Question 11

Why is the evolution of complex lifecycles an important adaptation?***

Answer 11

Reduces intraspecific competition between larva and adult since different life stages have different feeding patterns and mobility.

Question 12

What are the entomology ‘big four’

Answer 12

1. Lepidoptera (Butterflies and moths with caterpillar stage as larva) (ex. Gypsymoth)
2. Hymenoptera (Parasitoid wasps, bees, wasps, ants) ecosystem engineers and keystone species.
3. Diptera (2 winged flies, true flies) vecors of disease (mosquito, tsetse flies, horseflies etc)
4. Coleoptera (beetles)
   - All 4 have complex life cycles and larva - pupa - adult stages.

Question 13

What are the 2 methods of metamorphosis?

Answer 13

Hemimetabulous: Incomplete or gradual metamorphosis from larva - adult. As they grow, they look more like the adult they will metamorphose into.

Holometabulous: larva-pupa-adult “complete metamorphosis” featuring a pupa stage.

Question 14

What major group do dragon and damsel flies belong to?

Answer 14

Odonata: characterized by hemimetabulous development.

Question 15

What is meant by a “complete metamorphosis” ?

Answer 15

Holometabulous metamorphosis consisting of abrupt changes as the larva develops into a pupa and then adult. Characteristic of the big 4.

Question 16

Why do MPB conglomerate on certain trees?

Answer 16

The release of aggregation pheremones that induce a feeding frenzy.

Question 17

What is the auditory reception structure in most insects?

Answer 17

Tympanum. Made of cuticle, used for mate detection, substrate detection, predator evasion.

Question 18

What are mechanoreceptors?

Answer 18

Bristles / hairs designed to detect vibrations in the air.

Question 19

What are 2 additional adaptations that make insects successful? Hint: one is reproductive, the other is functional.

Answer 19

-Evolution of ovipositor and resistant egg stage where eggs can be laid in inaccessible places until they hatch.

-Tagmatization: the development of 3 main divisions (head, thorax and abdomen) allows for greater division of labour. Each segment has a seperate function and all 3 work together.
Head: feeding, Thorax: locomotion, Abdomen: reproduction

Question 20

What are the 5 major mouthpart appendages And their functions?
Also, what is a palp?

Answer 20

Labium: combine with maxillae for chewing and lapping (common in bees for wax manipulation and feeding larva / queen.)

labrum: modified into labella, a spongelike mouthpart for lapping up liquids (flies)

maxillae: sucking up nectar from flowers (butterflies)
mandibles: biting and chewing

hypopharynx: piercing and sucking
palp: a modified sensory mouthpart on some insects.

Question 21

What is suicidal monogomy?

Answer 21

A reproductive adaptation where a male bees penis explodes into the queen (copulatory plug) to prevent other males from mating and ensuring his sperm fertilizes her eggs.

Question 22

What are the 3 functional feeding groups?

Answer 22

Saprophagy – feeding on dead organic matter. Major decomposers and nutrient recyclers (Termites, Dung beetles, springtails).

Phytophagy – feeding on all parts of living plants (Seed and cone feeders, leaf feeders, root feeders.)

Zoophagy – feeding on living animals (Parasitoid wasps, predatory carnivores like dragonflies)

Question 23

6 types of saprophagy

Answer 23

General scavengers (e.g. cockroaches)

–Humous feeders (springtails)

–Microbivores (stonefly nymphs)

–Feces specialists (dung beetles)

–Dead animal specialists (carrion beetles)

–Dead plant specialists (termites)

Question 24

6 types of phytophagy. ***

Another name for phytophagy

Answer 24

Aka herbivory

-Seed and cone feeders (beetles and moths)

–Leaf feeders (caterpillars, leaf miners)

–Nectar feeders (bees, flies, butterflies)

–Sap-sucking feeders (Hemiptera)

–Attached aquatic algae (stream insect nymphs)

–Root, stem or fruit eaters (beetles, flies)

–Gall-forming specialists (flies, wasps)

Question 25

What would be the big 6

Answer 25

The big 4 plus

• Hemiptera (true bugs) and Odonata

Question 26

Why is phytophagy important in the evolution of plants?**

Answer 26

The diversity of insects allows them as a group to target all parts of plants. Plants react to this constant feeding, putting them in a state of constant adaptation in response to insect inputs.

Question 27

5 types of zoophagy?

Answer 27

-Ectoparasites (fleas, lice)

–Endoparasites (botflies)

–Parasitoids (wasps) - primarily feed on caterpillars

–Predatory carnivores (dragonflies)

–Micropredators (blood sucking flies, hemiptera)

Question 28

What senses are associated with the head?

Answer 28

Mouthparts, photoreception, chemoreception via antennae.

Question 29

What functions are associated with the thorax? What are the segments of the Thorax?***

Answer 29

Thorax main function is locomotion

3 segments: pro, meso and metathorax. Each part holds a pair of appendages. The meso and metathorax hold a pair of wings each.

Pro: front pair of appendages. Used for predation

Meso: one pair of wings and one pair of appendages (elytra in Coleoptera)

Meta: one pair of wings one pair of appendages (haltere in Diptera)

Question 30

Metathorasic wing.

Answer 30

In Diptera, a small modified wing known as a haltere. Distinguishing feature.

Question 31

What is a distinguishing feature of coleoptera ?

Answer 31

Forewing (mesothorassic wing) modified into “elytra” hardened structures that provide massive protection.

Question 32

What is a distinguishing feature of Lepidoptera?

Answer 32

Tiny scales on wings.

Question 33

How many segments are in the abdomen. What is it used for?**

Answer 33

9 - 11 segments

Adapted for reproduction.

• ovipositor in females found on segments 8 and 9
• segment 9 in males forms aedeagus (penis).