Nitidulidae (Also known as Sap beetles)
Sap beetles are usually small, dull coloured beetles that have little clubs at the end of their antennae. They mainly feed on over ripe fruit, decaying vegetables, and sap, although the pollen beetle is an exception and feeds on pollen and nectar.
What do they look like?
This beetle is very small, roughly 2-2.7mm in length, they are black in colour with a metallic green/blue sheen. Pollen beetles are a broadly rounded oval shape, with short antenna that are clubbed at the end. The other species in this genus do look similar, although you can distinguish this species by examining the shapes of the different segments of the beetle (head, thorax, abdomen).
Where do they live?
Pollen beetles are particularly common in fields of Oil Seed Rape, so much so, that they are considered pests of this plant. They damage the buds, causing the flower to drop off. They can also be found on other flowers, especially those that are yellow in colour.
Where can they be found?
Pollen beetles are very common in England and Wales, although its distribution decreases in Scotland.
When can you see them?
Pollen beetles can be seen from spring to late autumn.
The adults can be seen on mainly yellow flowers, feeding on the pollen and trying to locate appropriate plants to lay their eggs in. Once they find the appropriate plant, they lay their eggs (oviposit) in the buds of the plant where the larvae will then hatch and feed on the pollen.
Larvae will then fall to the ground and bury themselves in the soil to start the process of turning into an adult beetle (metamorphosis).
Adults later emerge and begin to feed on the pollen of any accessible flowers before overwintering among vegetation. These beetles have one generation a year.
What do they do?
As pollen beetles feed on pollen, the beetle carries pollen from flower to flower which helps to pollinate the plant. This fertilises the plant and allows the plant to reproduce.
Did you know?
Pollen beetle larvae feed on the sexual parts of the flowers, especially in plants within the Cabbage family. This means that the plant can no longer reproduce, making the pollen beetle a pest for some gardeners.