- Slides: 15
Understanding challenges facing pollinators Aseel Samaro
§ It a scanning electron micrograph (SEM) of a pollen basket of a worker honey bee § Worker bees go from flower to flower collecting nectar and pollen to feed the colony § They collect pollen into a basket on their legs; pollen also sticks to tiny hairs that cover its body § The bees pollinate many of the crops that we eat and without them, we would find it hard to find enough food to survive
Understanding challenges facing pollinators § Honey bees used to pollinate 70 per cent of the UK’s insect pollinated crops. § Today, it is less than 30 per cent. § However, the growth of some crops has risen, suggesting that other insects have been taking the place of honey bees. § Pollinators must be protected to make sure we don’t lose crops.
Important pollinators Most cereal crops are wind pollinated. However, insect, bird and bat pollinators are responsible for 35 per cent of global crop pollination, including pollination of: üFruits üNuts üSeeds üBeans üCoffee üOilseed rape üOnions üAlmonds ütomatoes
§ Butterflies and bees are among the most important pollinators. § Bees collect pollen from plants to make honey. § They are usually specially adapted, with a furry body, so they can collect the maximum amount of pollen. § Some of this lands on other plants as they move from plant to plant.
Name three other crops we rely on insects to pollinate. Why are bees so useful as pollinators? Because they are specially adapted to collect pollen. If a plant relies on one species of pollinator, what will happen if the pollinator dies out? The plant species will die out because it cannot reproduce without transferring pollen
Confused bees § Since 2005, more than ten million bee colonies have been wiped out by colony collapse disorder (CCD), possibly caused by pesticides. § Bees become weak and confused, and can’t find their way back to the hive. § This results in a reduction in the size of the colony, a shortage of food for the remaining bees and the inability to reproduce successfully. § Many bees have also shown signs of increased viral disease.
Theories about the causes of CCD include: 1. Pesticides such as insecticides are sprayed on crops to prevent insects and fungi from attacking them. Unfortunately it is not possible to target specific insects, and others may be affected. Some contain nicotine, which is thought to cause confusion in the brain of the bee.
2. The number of wild flowering plants has reduced as more land is used for development and agriculture leading to less variety of pollen and a narrower range of nutrients for bees.
3. Farmers rent out hives to pollinate crops. This can disorientate bees, which find their way around by locating routes back to their hives. Also, disease can be spread more widely because hives from different locations come into close contact, which would not occur naturally.
4. Climate change means that some plants are flowering earlier, before bees can fly.
5. Bees are more susceptible to virus attacks because other factors have made them weaker.
Did you know ? § In the USA, bees are the only pollinators of almond trees. § Farmers are completely dependent on an active bee population for a good crop.