When the pollination through insects, its called

When pollination through insects, it's called Entomophily.
Entomophily or insect pollination is a form of pollination whereby pollen of plants, especially but not only of flowering plants, is distributed by insects.
Flowers pollinated by insects typically have bright colours, also have an attractive scent. And the ideal pollinating insect is hairy.
The attractions offered are mainly nectar, pollen, fragrances and oils.