According to FAO, around 40% of invertebrate pollinator species particularly bees and butterflies face extinction across the world. In this context, which of the following are causes for the decline in the number of pollinators?
1. Increasing use of neonicotinoids
2. Change in the cropping pattern
3. High environmental pollution from heavy metals
4. Growth of invasive alien species
Select the correct answer using the option given below.
(a) 1, 3 and 4 only
(b) 1, 2 and 3only
(c) 2 and 4 only
(d) 1, 2, 3 and 4
Answers
Option D - 1, 2, 3 and 4
■ Explanation :-
- More than 180,000 plant species, including 1,200 crop varieties, across the world, depend on pollinators to reproduce. But the little creatures, like the bees and the butterflies, have increasingly been under threat.
- There are two categories of pollinators: invertebrates and vertebrates. Well-known invertebrate pollinators include bees, moths, flies, wasps, beetles and butterflies. Around 40 per cent of invertebrate pollinator species — particularly bees and butterflies — face extinction across the world, according to the FAO. In India, wild honeybees of the genus Apis — including the Asian bee (A cerana) and the little bee (A florea) — declined steadily for the past 30 years.
- There are several causes for the decline in the number of pollinators. Most of them are the result of an increase in human activities :-
》Global warming causes flowers to bloom earlier or later than usual. When pollinators come out of hibernation, the flowers that provide the food they need to start to start the season has already bloomed.
》It’s not that the pesticides which are aimed at other insects are killing the bees outright. Rather the sublethal exposure of pesticides in nectar and pollen may be interfering with the honeybees internal radar, preventing them from gathering pollen and returning safely to the hive. Neonicotinoids are a new class of insecticides chemically related to nicotine. They are much more toxic to invertebrates.
》Bees absorbing metal pollution from flowers that absorbed it from the soil that absorbed it from modern machines and vehicles.
》Change in the cropping pattern and crops like the cultivation of Genetically Modified Organisms (GMOs) and mono-cropping has also led to a decline in the bee population.
》Biological invasions of alien species result in habitat change, loss and fragmentation of the native species. A key ecosystem service that has the potential to be interrupted by the arrival of novel species is pollination. Threats to wild bees have been more widely studied than impacts on other pollinator taxa. Habitat change, loss and fragmentation associated with agricultural intensification are thought to pose the main risks to native bees.
- Hence all the above are the causes for decline in the number of pollinators.
Hope It helps you.