Abundance, Diversity, and Importance of Insects Flashcards
Abundance (total number)
Insects have the largest biomass of all terrestrial animals. 80% of all animals on the planet are insects
Diversity (species richness)
Currently 1 million described species
Insect success
Insects have colonized most major biomes and habitats except the ocean
Reasons for insect success
- High reproductive capacity
- Ancient lineage
- Exoskeleton
- Wings
- Small size
- Complete metamorphosis
High reproductive capacity
- Short generation time
- Populations build up faster
- Faster rate of mutation
Ancient lineage
- Ready to exploit new environments
- Less competition
- Long time to adapt to a wide variety of environments
Exoskeleton
- Protection from physical damage
- Discourage predators
- Barrier between living tissue and environment
- Protects against desiccation
Wings
- Advantage in finding food, mates, and escaping from enemies
- Can move freely from one habitat to another to find better conditions
Small size
- Require little food
- Exploit micro habitats for food, protection, environmental conditions, and nesting
Complete metamorphosis
- No competition between same species since different body forms = different habitats and food
Importance of insects
- Pollination
- Food source
- Nutrient cycling
- Soil improvement
- Control of other organisms
- Medicine and genetics
- Biological indicators
- Commercial products
- Aesthetics and culture
Pollination
- almost the only animal pollinators
- Bees are the most important pollinators
Pollination process
- Pollen from stamens stick to the pollinators body when it collects flower nectar
- Pollinator carries pollen to another flower
- Pollen from the pollinators body is deposited on the stigma to complete pollination
Food source
Food source for birds, mammals, fishes, amphibians and reptiles, domesticated animals, and humans
FDA legal tolerance for insects in food
- 60 aphids per 100g
- 60 microscopic insect fragments per 100g
- 30 fly eggs and 2 maggots per 100g
Nutrient cycling
Involved in the decomposition of organic matter
Soil improvement
- Aerate the soil
- Improve physical properties
- Add to organic content
Control of other organisms
Parasitoid and predatory insects are often used in biological control of insect pests
Medicine and genetics
- Maggot therapy
- Knowledge about mutations and genetic inheritance
Biological indicators
Indicators of pollution and habitat change
Commercial products
- Honey and beeswax from honeybees (Apis mellifera)
- Silk from silk moth (Bombyx mori)
- Red dyes from the female cochineal
Aesthetics and culture
Insects have inspired works of art and jewelry
