Lecture 4

Question 1

Evolution and Natural Selection

Answer 1

change in gene frequency in population driven by natural selection.
Natural selection factors in environment that cause survival and reproduction differences, more favorable traits

Question 2

Natural Selection Processes

Answer 2

Disease, harsh environment, competition (for anything), predation, parasitism

Question 3

Artificial Selection Processes

Answer 3

Insecticides, Habitat Destruction, and global warming
Basically human made (ex. peppered moth turned darker due to industrial revolution)
Good ones= breeding, biocontrol

Question 4

Insect Evolution

Answer 4

Strong fossil record. Compression fossils. Collembola: Springtails.

Question 5

Evolution in Wings

Answer 5

Class Insecta
Subclass- Apterygota (no wings), Pterygota (wings)
Infraclass (pterygota)- Paleoptera (non-folding like dragonfly) and Neoptera (folding)
Superorder (folding)- Exopterygota (incomplete metamorphosis) and Endopterygota(complete metamorphosis)

Question 6

Giant Insects

Answer 6

Dragonfly that was 27 inches. Ephemeroptera was 17 inches. They were so large back than because of oxygen. There was 30% more O2 and flying vertebrates caused the large insects.

Question 7

History

Answer 7

• Carboniferous=3 main feed strats= External, Internal, and full developed predators. Plants were largely ferns.
• Permian=Gymnosperms developed and insect diversity exploded. More food for insect, thin cortex and phloem
• Triassic=Dinosaurs and mammals orgin. Diversification of insects and major orders represented.

Question 8

Amber Insects

Answer 8

Cretaceous to Tertiary plant secretion led to high quality preservation.

Question 9

Mouth-Parts

Answer 9

Beak like mouth parts and expanded clypeus were evidence of feeding on phloem and other plant parts

Question 10

Morphological Evolution of Insects and Mammals

Answer 10

• Humans have fast rate of evolution compared to insects due to recent radiation and major extinctions.

Question 11

What was the first insect?

Answer 11

The first insect was terrestrial. Tracheal system evolution show that gills form only after tracheal system. Proof of terrestrial first.

Question 12

Insects vs Animals

Answer 12

Insects have way more species than animals

Question 13

What events cause more species in insects?

Answer 13

Evolution of wings- no limbs were lost and they did not come from gills. Epicoxa means wings develop from base of legs. Paranota means it came from thoracic terga. There is genetic evidence that wings develop from both, fusion hypothesis.

Question 14

Early Wings Function (non-flight)

Answer 14

Protect legs, covers spiracles, thermoregulation, sexual display, concealment, escape

Question 15

Evolution of flight

Answer 15

Only paragliding, not floating, running and jumping, and surface sailing across water. Earliest wings used for paragliding.

Question 16

Folding wings

Answer 16

Neoptery, dragonfly and mayfly are NOT examples since they can’t fold wings.

Question 17

Insects with wings and that can fly have way more species than insects without wings. WHY?

Answer 17

Increased mobility=more resources/habitats. Evade predators.

Question 18

Allopatric speciation and Sympatric speciation and Parapatric speciation

Answer 18

Allopatric=Species that arise from being geographically isolated.
Sympatric= Species arise in same area by temporal shifts/behavior
Parapatric=Species arise from spacial separation but share border.

Question 19

Complete Metamorphosis

Answer 19

Eggs to larva to pupa to adult

Question 20

Evolution of Metamorphosis

Answer 20

• Permits adult to feed on new resources
• Permits adult to exploit new habitats
• take advantage of new situation

Question 21

Characteristics of Insect Success

Answer 21

1) Small size=more niches available to small animals
* 5 species of insect only marine. 97% terrestrial, 3% aquatic. Insects specialize in niche.\
2) Enormous reproductive rate. Fecundity, longevity, generation, an time are all factors.
3) Tough exoskeleton
4) Flight

Question 22

Biogeography

Answer 22

Study of the distribution of species and ecosystems in geographic space through geologic time. Insects show patterns of restriction in one area so entomologists are prominent biogeographers.
* just think insect distribution
Becoming more difficult due to Anthropophilic insects, humans disturb habitats, parasites, dissemination, deliberate movement.
Bottom line: Applied entomologists must take worldwide perspective