Insect Diversity

Question 1

How diverse are insects? Give numbers.

Answer 1

• 5-20% of species described​
• 3 million to 80 million​
• 4 to 6 million realistic​
• 400 mya
  Greatest diversity in tropics, so this is where most of undescribed species likely to live

Question 2

What features of insects contribute to success and diversity?​

Answer 2

Small size (0.3 mm – 30 cm, 75% < 6mm) ​
- why small? Circulatory/respiratory systems, external skeleton​;
Highly organized sensory and neural systems​;
Short generation times​;
Flight​;
Complete metamorphosis​;
Metamorphosis reduces competition between immatures and adults​;
Sexual selection​;
Coevolutionary relationships with plants, hosts​;

Question 3

Why are insects important?​ Positive Roles.

Answer 3

Basic biological models​;
Food for insectivorous animals​;
Source of food, textiles, and other products​;
Source of novel chemicals;
Maintenance of animal and plant communities via herbivory, parasitism, disease transmission​;
Nutrient recycling (wood, litter degradation), soil creation, etc.​

Question 4

Why are insects important?​ Negative Roles.

Answer 4

Pests of crops and livestock​
Pests of structures
Vectors of diseases​