Imagine being outside in the summer an seeing all kinds of butterflies flying around. It’s a beautiful sight and you wonder, how do they live and grow?
Well, we did the wondering for you. We asked ourselves these questions and set out to find the answers.
In this paper you will find two experiments to answer these questions. The first is about the development of the eggs of the Large Cabbage White. Which circumstances are best for them, do they grow better when it’s warm and which food makes them grow biggest. With this they need light of course, as long as in summer, at least 16 hours a day, so that we also gave them. We measured and weighed the caterpillars and pupas. We also measured how long it took the eggs to become a pupa.
The next experiment is with butterflies. Butterflies eat different foods then caterpillars, they need sugar. So in an behavioural experiment we tested which food they like best, we chose honey, pure sugar and banana.
Curious? Read on to find out our results and how you can do it yourself!
Which living conditions are best for the development of the Large Cabbage White and which food do they like best?
What is the influence of different temperatures and foods on the development of the Large Cabbage White?
Which food does the Large Cabbage White like best?
Hypothesis The Large Cabbage White develops fastest in a temperature of around 20 ºC because this is found in our literature
The Large Cabbage White develops fastest when it has Kale (Boerenkool) to eat, because that is implicated in our literature
Favourite food of the Large Cabbage White is the mix of sugar and water, because they need sugar and therefore pure sugar is the most nutritious for them.
The Large Cabbage White (Pieris Brassicae) is one of the most common butterflies living in the Netherlands. Its eggs are laid in groups of around 60 on the underside of cruciferae leaves (kruisbloemigen). Cabbage plants are a part of this family. The host-plants for their eggs are recognized by the sensilla (gevoelige cellen) which female butterflies have at the end of the antenna and paws. When the eggs are laid, they stick to the plant like glue, this gives protection from the sun and prevents them from being washed off when it is raining.
The yellow eggs have ridges from the top to the underside. The eggs become more yellow during their development. The eggs hatch out after four days. The little caterpillars make a hole which is as big as their head with their jaws. First the head comes out, then the front legs, the hind legs are pulled out by its front legs. The caterpillar wriggles with its body to leave the egg as soon as possible, this minimizes the chance of getting eaten by its enemies.
When the caterpillar is out of the egg, the eggs shape is preserved by the ridges on it. The caterpillars first eat their egg, it contains some vital nutrients for them, then they start eating the host-plant. This is why the butterflies make sure they choose the right host-plant, the caterpillars eats only one kind of food, so if the wrong host-plant is chosen the caterpillars will not eat and then die quickly. The host-plants for Large Cabbage Whites are most kinds of Cabbage plants.
Caterpillars can’t breathe as humans do, their skin does not let oxygen through and they don’t have lungs. Caterpillars breathe through holes in the side of their body. These are called spiracles. Through the spiracles, oxygen goes through small tubes called trachea and is then absorbed by body liquids.
A caterpillar receives information about the environment by using two sensing organs, their antenna and their primitive light-sensitive eyes. The caterpillars body consists of segments and legs, it also contains a huge amount of muscle. The caterpillar moves by contracting these muscles in the rear segments, this pushes the blood to the front segments, it then elongates the torso forwards and start again for the next move.
Caterpillars have many ways to protect themselves from their enemies. Below are named a few of these methods:
Having a body with bright colours.
Camouflaging itself (having a camouflaging colour, looking like for instance a bird dropping, or something that belongs in the surrounding environment.)
Before caterpillars can turn into a pupa they have to grow. In order to fit into their skin but keep growing at the same time their skin peels off several times before changing into a pupa.
In seventeen days the caterpillars eat very much and grow thick and long, after which they start pupating. Pupating is changing into a pupa. Pupating happens under influence of hormones.
When talking about butterflies (dagvlinders) the stage before becoming a butterfly is called a pupa. When talking about moths (nachtvlinders) the name is cocoon.
Before a caterpillar starts pupating it searches for a suitable place. This differs from specie to specie. Some species do not need a safe space because of their dangerous appearance. The Large Cabbage White does not have a dangerous appearance, thus it needs a safe place to pupate. When a safe place is found the caterpillar climbs on a branch and turns upside down. Grabs the surface with its claws and fastens itself to the branch with silk fibres. These fibres are produced by the caterpillars abdominal gland (spinklier) and are spun around the caterpillars body after the caterpillar has attached itself to the branch, it has then turned around again. The pupating takes one or two days. The skin of the pupa is already present under the skin of the caterpillar. When the caterpillar starts twisting its body, the skin is easily ripped open. Slowly the old skin comes off entirely. The new skin is week at first, but dries out fast. The silk fibre around the body is maintained for safety. The caterpillar remains in place by claspers (staarthaken) which it fastens into its ‘spinsel’.
Being a pupa is the only possible way for The Large Cabbage White to live through winter.
The pupa of the Cabbage White changes colour over time. In the beginning it has a green colour, a few days before the pupa hatches out the colour has changed to light brown. The wings will be visible too.
After about eleven days the pupa hatches out, which only takes a few minutes. Sometimes the pupa moves to and fro, this increases a few days before it hatches out. The back of the pupa rips open and the butterfly starts to wriggle itself out. When it has hatched out its wings are still wet and folded up. Blood is pumped into the wings to pump them up. When the final shape of the wings has been reached the wings dry out, this causes the wings to loose their elasticity and stay in shape. The pumping of the wings does not take long and after it is done all the blood is pumped back out of the wings into the body of the butterfly. This makes the wings strong and light.
A butterfly can see colours and detect movements very well. It has eyes which are composed of a large number of smaller eyes.
The most important food for a butterfly is nectar gotten from flowers, but some butterflies also eat the juice of rotten fruit, dead animals, manure or urine.
The Cabbage White becomes sexually mature after 3 to 4 days after it has hatched out. It will start looking for a mating partner. The butterflies can live up to two weeks.
The male and female Cabbage Whites have a difference in appearance. The wings of the male are totally white on the inside, the wings of the female have two spots on the inside of each wing.