What Is the Difference Between Insect and Wind Pollination?
In wind-pollinated plants, the microsporangia is on the outside of the plant, so it can be blown off and be dispersed by the wind. Insect pollination, on the other hand, requires an insect to move the pollen from one place to another.
Plants that are insect-pollinated have very different features than plants that are wind pollinated. For example, insect pollinated plants need to attract insects, so they are brightly colored, smell sweet and contain nectar. There is no such requirement in a plant that is wind pollinated, so they often come in duller colors and have no smell or nectar.
The quantity and the makeup of the pollen are also different. For example, wind pollination is very much a scatter-gun approach, so a lot of the pollen that is produced does end up growing. For this reason wind pollinated plants produce a lot of pollen to increase the chances of success. This is not required if the plant is insect-pollinated, so less pollen is produced.
Also, the pollen in wind-pollinated plants has to be light and smooth so that it can be carried from place to place by the wind. The objective of insect-pollinated plants is to ensure the pollen sticks to the insects. This is achieved by producing pollen with spikes, or pollen that is naturally sticky.