Have fun and learn how insects pollinate flowers in this hands-on Plant2pollinator activity for Stage 1 students.
How do insects pollinate flowers?
Charles Darwin found a very long tubular flower in the South American jungle and predicted someday someone would find an insect with a tongue of matching length to reach the nectar at its base. After much searching and over one hundred years later, a moth was found. More recently an even longer tube flower has been found in Madagascar and the search in on for the insect pollinator.
Concepts and Key Words:
1. Pose the focus question How does an insect pollinate a flower? List and display all answers and questions as they arise. What does pollinate mean? To pollinate means to mix the male (pollen) and female (stigma and ovule) parts of the flower so the flower can reproduce.
2. Engage Why does an insect pollinate a flower? – flowers hold rewards of nectar (just like lollies!) Are there different flower shapes? Tubes (daffodil) and dishes (daisy/gerbera). How do you think an insect would collect nectar from the bottom of a tube? Some insects like butterflies and bees have long ‘straw-like’ tongues they can suck up the nectar with.
- Work in pairs
- Each pair is either a butterfly or bee
- Butterflies make tube flowers (one each) and bees make dish flowers (one each).
- Tube flower: Cut a length of straw 1 cm taller than the paper/plastic cup. Blue-tak the straw to the bottom of the cup. Place a cotton wool bud on top of the straw.
- Dish flower: Stick a cotton wool bud in the centre of the paper plate.
- Within the working pairs, fill one cup or dish with one layer of popcorn. This will be the male flower, cover cotton bud with powered chalk/sherbet/cinnamon.
- Place the empty ‘flower’ (female flower with plan cotton wool bud) several meters away from the male ‘flower’
- In the pair, one person is the ‘insect’ the other is the popcorn counter.
- Butterflies: use a small length of straw (just shorter than the height of the cup, approx. cm) in your mouth to suck up a piece of popcorn, deliver it the other flower.
- Bees: use a very small length of straw (approx 2.5 cm) in your mouth to pick up the popcorn, one piece at a time and deliver it to the other dish flower.
- Once all the popcorn is transferred from one flower to the other, sit down near your flower and look at the ‘insects’ face. Is it covered in pollen?
4. Explain Flowers are shaped so when a particular insect collects nectar, it gets covered in pollen. When it visits the next flower the pollen gets transferred. This is pollination – a seed or fruit will now appear!
5. Elaborate Discuss different shaped flowers and different ways insects eat. E.g. butterflies use long straw like tongues and so can reach the nectar in the bottom of the tube. Bees only have short mouth parts and can only collect nectar from flat flowers.
6. Evaluate development of understanding by posing questions. If insects were removed from the environment, could flowers still transfer pollen? Mostly, no. So what would happen to the plants? No fruit, no more flowers etc.
- Plastic or paper cups
- Paper plates
- Cotton-wool buds
- Sherbet/powdered chalk/cinnamon
- Safety glasses optional
Insects obtain food from the flowers they visit, usually in the form of pollen or nectar. In return for this food the insects carry the pollen from one flower to the other, allowing the plant to reproduce. Flowers have characteristics that attract insects and insects have specialised mouth parts to gain access to nectar.
Proctor, M., Yeo, P and Lack, A. 1996.The Natural History of Pollination. Timber Press Inc. USA.