Buff-tailed bumblebees collecting nectar and pollen from inula flowers, a good example of a garden plant that attracts pollinators. Natural pollination by bees and other insects is of ecological and financial importance as it improves the quality and quantity of agricultural crops, but there is growing concern in the decline in the numbers since the mid 1990s of these natural pollinators. Intensive agriculture is a major cause with the use of pesticides and herbicides and the loss of habitat and food for bees. Some bumblebees imported from abroad to pollinate fruit crops have been found to carry pathogens which has spread disease amongst native colonies.