Pollinator series

Pollinators: Beetles, true bugs and thrips

Written by Thary Gazi Goh
Photos by Thary Gazi Goh

These are pollinators that crawl around flowers. Sometimes they crawl into flowers as protection, sometimes they are looking to feed on pollen, sometimes they randomly pick up pollen while doing something else.

Accidental pollinators

Some insects can pick up pollen as they move around

Sometimes crawling insects can pick up pollen as they move about in search of other food. Ladybugs are known to be minor pollinators, and other crawling insects can do so as well. However, they aren’t very good pollinators since they don’t move as far as bees or butterflies.

Ladybugs hunting for other smaller insects can pick up and move pollen

Examples: Ladybugs, true bugs, beetles

Flower Structure: Plants that can be accidentally pollinated usually produce a lot of sticky pollen.

Pollen feeders

Some beetles feed on pollen grains and the plants that are pollinated by beetles develop specialised relationships with the beetles that feed on their flowers. Often, these plants produce large amounts of sticky pollen in tight spaces that force beetles to crawl through to get to. These flowers also either have no petals or very tough petals that can withstand the biting damage of beetles. 

An oil palm weevil. Photograph by Ken Walker, distributed under CC-BY 3.0 license.

A good example of beetle pollination is the oil palm, which is mostly pollinated by a small beetle, the Oil Palm Weevil (Eleidobius kamaroonicus) that has been introduced from Africa.

Aside from beetles, small animals like thrips also feed on flower pollen. These can be pests of crops as they feed on flowers and sometimes spread plant diseases.

Many primitive trees from the Magnolia family are pollinated by beetles.

Examples: Oil Palm Weevil, Sap beetles, Fungus beetles, Thrips,

Flower Structure: White, green or yellow flowers with tight pollen compartments or open bowl- shaped flowers. Usually have thick petals or sometimes none at all. Some aroids are known to attract beetles by heating up.

Plants that they pollinate:  Aroids, Magnolias, some palms.

Flower brooders

Flower brooders are insects that breed inside of flowers, using the flower as both a source of food and shelter. Some flower brooders breed in fallen flowers and survive on fungus that grows inside. Some live in living flowers and damage them from the inside. The movement of these animals from flower to flower spreads pollen.

Thrips on a flower. Photograph by xpda, distributed under a CC-BY SA 4.0 license.

Sap beetles and thrips can be found living inside flowers, feeding on pollen or the flower itself. These weak fliers can move between flowers to spread pollen.

Examples: Sap beetles, Rove Beetles, Thrips

Flower structure: Usually part of the flower forms a protective chamber that can only be accessed by crawling insects. 

Plants that they pollinate: Bean flowers (but they cause damage as well)