Insect Biology and Flight Mechanics

Study Notes

Insects are the most successful animals on Earth, with more species and individuals than any other life form.
Their success is attributed to factors such as small size allowing access to various niches, short generation times for rapid adaptation, and metamorphosis for specialization.
Insects exhibit diverse feeding habits and are found in various habitats worldwide, impacting other life forms significantly.

Dragonflies were among the first insects to evolve flight.
Different insect groups have modified wings for specific flight patterns, like bees and wasps, butterflies, and beetles.
The evolution of flight provides insects with numerous advantages, including escape from predators and efficient dispersal.

Insects undergo metamorphosis, a process of physical transformation from one body form to another.
Two main types of metamorphosis exist: incomplete (gradual) and complete (abrupt).
Incomplete metamorphosis consists of three stages: egg, nymph, and adult. Nymphs resemble smaller adults and occupy the same habitat and diet.
Complete metamorphosis consists of four stages: egg, larva, pupa, and adult. Larvae are significantly different from adults and often occupy distinct habitats and have different diets.

Around 85% of insect species exhibit complete metamorphosis.
This allows specialization of adaptations and lifestyles between larval and adult stages, reducing competition and mortality from different predators.
Specialization between stages helps maximize resource utilization, with eggs representing the embryonic stage, larvae as the main feeding stage, pupa as the reconstruction stage, and adults for reproduction and dispersal.

Different life stages of insects are vulnerable to predation, leading to the development of various protective strategies.
Camouflage (crypsis) allows concealment through body shape and colors matching the environment.
Aposematism involves bright colors or patterns warning predators of distasteful or toxic features.
Mimicry involves mimicking the colors or patterns of toxic species to deter predators.

Insects reproduce sexually, relying on various strategies like bright colors, sounds, or odours to identify members of their own species.
Fertilization is internal, and eggs are laid on food sources, ensuring a continuous cycle of reproduction.