Hey, you’re back! I hope you’ve read Understanding Insect Life Part 1: From Egg to Larva, because you might be a little confused if you haven’t!
For those of you who are up to date and know everything there is to know about eggs and larvae, you have my blessing to read on.
Cocoon: extreme transformation!
We’re not talking about a new wardrobe and a bit of botox here, but a very real metamorphosis! It’s the moment when you can go from worm to bug with legs, from terrifying war machine to pretty ladybug, even from aquatic to terrestrial life!
I don’t really like the word “nymph” because it refers to too many things, but it’s the official name for this stage where larvae enter once they’ve eaten and grown big enough. They find a quiet place safe from predators, make themselves a little sleeping bag from silk or other materials they produce, and begin to change.
Wings and/or legs grow, the mouth adapts to its next feeding mode, the eyes change, the color too… In short, few things stay the same!
Just for your viewing pleasure, here are a few transformations I find spectacular:
Dragonfly
The dragonfly has an aquatic larva and is a lifelong predator. The egg is laid directly in the water, and the larva hunts small prey in rivers, but can also prey on small fish. As an adult, it has extremely precise and powerful flight, huge eyes for 360° vision and amazing hunting skills in flight. If you live near water, these are your friends!
Mayfly
I’m cheating a little with this one, because the mayfly doesn’t actually have a complete metamorphosis, since it doesn’t have a cocoon stage. The aquatic larva gradually changes to become a flying adult. What’s fascinating about the mayfly, however, is that the adult doesn’t eat. It lives only a few minutes to a few days, the time it takes to reproduce, and then dies!
Butterfly
The butterfly, a classic, but with a rather impressive change in its diet. It feeds on plant leaves in its caterpillar stage, then develops a proboscis in its chrysalis (or pupa) to drink flower nectar as an adult. It’s a whole new way of feeding!
Adults and Their “Great” Responsibilities
Once it has emerged from its pupa, the insect is said to be an adult. And what all adult insects have in common is that, just like larvae, they have a single goal that takes up all their time. However, it’s not to feed, but rather to reproduce.
I know, I know… eat, eat, eat, take a loooong nap in a sleeping bag, then fuck… er… find mates to make babies with.
Dream life. Short, yes, but full of good things!
I’m obviously joking, but insects aren’t very complex animals. They don’t need to play, exercise, feel safe or stimulate their senses like most animals in the wild. They can spend all day in one place without suffering mentally or physically.
Nevertheless, gardeners should beware: some insect pests are adults! Beetles in particular. Chrysomelids, flea beetles, Colorado potato beetles, Japanese beetles… Just because their sole purpose is reproduction doesn’t mean they don’t eat!
Waves and Disappearances
“This year, it’s unbelievable how many mosquitoes there are!”
“In my day, there were a lot more bugs…”
“Ticks are coming to the area…”
Insects are born in large quantities and quickly. If there’s a lot of rain, if spring comes early, if a certain type of plant was particularly present the previous year, it’s possible that an insect will take advantage of this to lay eggs in large quantities. Can you predict this? Well, not really…
Some species are cyclical. For example, it’s possible to have a spectacular cicada emergence every 17 years!
Others are weather-dependent, and their presence can vary enormously from week to week.
Still others are only present at a specific time of the summer, depending on the photoperiod (length of daylight).
It’s the life cycle that influences all these comings and goings. The duration of each phase differs from one insect species to another, as does what triggers egg-laying. While some species, such as fruit flies and mosquitoes, complete their cycle in a matter of days, others can take several years.
Because of their numbers, size and ability to fly, insects are very, very mobile from one region to another. A shovelful of earth with tiny eggs and whoosh! An insect has just arrived from Africa with a shipment of monstera! A storm, strong winds, a hot summer? Boom! Insects migrate north and ticks arrive North. Many invasive species are insects, and it’s no mystery why!
It seems like every year or so, a new insect makes the news! Sometimes it’s a pretty butterfly that’s had the ideal conditions to lay its eggs in abundance, sometimes it’s a new invader arriving in the region. Insects move fast!
Resilience and Fragility
With very few exceptions, insects spend the winter in hibernation, at any stage. Depending on the species, larvae may hibernate in trees, adults in the walls of your home (like ladybugs in the countryside!), nymphs in the soil, and so on. Each species has its own strategy for re-emerging the following year.
Although generally adaptable, insects are highly sensitive to disturbance, as many are selective. Take the monarch butterfly, which feeds only on milkweed. It’s not the only insect to be so dependent on a single food source. Think about it the next time you redo your flowerbed: some insects may desert your plot if you remove their favorite plant!
Did u really use the word f**k in your article? Good info, that just took me by surprise.
Great article! The dragon fly brought me back to my youth. We would enjoy time on a lake and the dragonfly nymph would shed their shells on the wooden piers emerging into adults.All that would remain is the empty husk. It was amazing.