The Scythe is a tool that can be purchased at Red HQ for 3.5 million honey. It has a maximum pollen collection rate of about 320 per second. To get access to it, you need to have 15 bees and discover 4 different red bee types.
The Scythe's average pollen collection rate is 177.78 pollen per second: 320 from red flowers and 106.67 from blue or white flowers.
In terms of absolute numbers, the Scythe collects the same amount of pollen per second as the Bubble Wand from the Blue HQ. However, the Scythe's shape is somewhat better suited to collecting goo.