Natural History

Insects have exoskeletons, not bones like other animals. For this reason, scientists do not see as many clear fossils of insects, as they do with other animals- but they do exist. We do know that  early insects likely began to emerge in the carboniferous era, which is characterized by the emergence of vascular plants, amphibians, and later on, reptiles.

Insects, due to the higher oxygen levels and lack of sky predators (birds did not evolve until much later), were giants compared to what we see now! For example, there is evidence of dragonflies with a wingspan of 28 inches! They developed wings and other adaptations such as feeding parts during this era.

The insects that we know today likely came from the Cenozoic period, about 65 million years ago in co-evolution with flowering plants. Due to this co-evolution, plants and insects still depend on each other for survival- think pollination, habitats, nesting, and food sources.  

Insects were the first animals with the ability to fly; all the predators were still living in water- this gave them a huge advantage in getting away from predators and played a huge part in why they are the most abundant animal group to this day!

See Evolution Timeline

Ecology 

Insects are so important for our environment, although often overlooked. Ecology refers to the relationships in a given environment. Insects are crucial in virtually every environment on earth, making up the largest group of species in the world, with billions of species of each. They do so much work for the health of our planet in three key ways:

They are a vital food source for birds, mammals, amphibians, fish, reptiles, and more. Did you know we have carnivorous plants on PEI? The Pitcher Plant requires flies and other insects to get nutrients- without them, it would not exist. 

They are decomposers. Fallen logs do not break down on their own- insects and other invertebrates eat and digest the wood, creating the transition from solid wood to becoming part of the forest floor. This is a crucial step because it enables the energy that the plant has gathered to return to the soil after its death and offer its nutrients back to the forest.

Insects spread seeds and pollen. Without pollination, we would not have food to eat. Bees, butterflies and many others contribute to pollination of fruits, berries, vegetables and many other plants in our ecosystem. Did you know that it is only female mosquitos that bite for blood? The male mosquitos are huge pollinators, without them, we would suffer.

Insects like ants will carry seeds across an environment to feed on it, or share it with their nest, but may drop them along the way, leaving that plant to grow in that area.

Key Characteristics of Insects

Not all Insects are created equal: They all have special adaptations they need to thrive and defend themselves in their environment. For example, the Spittlebug is a small insect that uses the water from within a stem or leaf of a plant, and produces a spit-like bubble around itself, to ward off predators. 

Body Structure -Insects have a head, thorax and abdomen, six legs and wings. Not all individual insects have wings but members of their species will. For example, worker ants don’t have wings but queens and drones do.

Exoskeleton - Insects are invertebrates, meaning they wear their skeleton on the outside. It is made of chitin and must be shed before an insect can grow. Insects begin their life as an egg and then go through a series of changes or metamorphosis in form as they approach adulthood.

Insects are a group of arthropods, meaning they have an exoskeleton, with 6 legs. Insects can be separated into subgroups by some key distinctions: Bugs (marked by an X on the back), Beetles (harder shell, wing line down the middle), and Flies (two sets of wings). Arachnids have 8 legs and are thus not insects.

Communication - Insects are equipped with powerful communication techniques for things like signalling danger, mating, or finding food. Pheromones are scent secretions that many insects emit to communicate. For example, some moths can send signals 10 miles away to let others know they're ready to mate. Other communications include using humming, clicking, vibrations, and light (lightbugs).

Colonizing insects- Insects that live in social groups, with a designated queen, and workers, all living together for survival. Examples include bees, wasps, and ants.

Movement- Although they are small, insects have incredible adaptations for movement, such as the ability to walk on water (like the predacious diving beetle), and having water-resistant wings. Insects have the only 'true wings' of the animal world. Other flying animals, like bats and birds, have modified forelimbs. Most walking insects have a tripedal gate- meaning at least three feet are on the ground (two from one and one from the other) at a given time, making them very stable movers and fast.

Life Cycle

Insects reproduce by laying eggs. Where they are laid varies greatly depending on species- some lay eggs in water, inside plants, others in soil, or decaying organic matter- just to name a few! Some species of wasp will even use a special adaptation called an ovipositor to lay their eggs in a host animal!

Life cycles vary greatly from insect to insect. For example, Mosquitoes go from an egg to an adult in a matter of days, whereas the Cicadae after hatching, live buried underground eating roots and microorganisms for 12-17 years!

Metamorphosis - Insects reproduce by laying eggs that hatch into insect nymphs or larvae. Nymphs look like their parents and grow by a series of moults until they reach the adult stage. This process is known as incomplete metamorphosis. 

With complete metamorphosis, the young insect or larva looks nothing like its parents; it grows again and again by moulting until it reaches the pupal stage, forms a cocoon and rests while metamorphosis takes place. 

They might be diurnal, nocturnal, or crepuscular, like other animals, only moving in certain parts of the day. This is so that they can maximize their survival rates. Some Moulting insects have instinctually evolved to time their moulting (a vulnerable time) when the moon's cycle is at its darkest so that they are less visible to predators.