Other Pollinators — Beetles
Much has been written about the importance of butterflies and bees to the pollination
process. However, many of us never considered the importance of beetles to this
It makes sense, considering the fact that about 450,000 species of
beetles are known, comprising about 40 percent of all known insects.
Of the world’s almost 350,000 flowering plants, it is thought that beetles are
responsible for pollinating close to 90 percent of them.
The first beetle-like organisms in the fossil record date back to the Permian Period,
roughly 270 million years ago. True beetles – those that resemble our modern-day
beetles – first appeared about 230 million years ago. Beetles were already in existence
before the breakup of the supercontinent Pangaea, and they survived the K/T extinction
event thought to have doomed the dinosaurs. How have beetles survived for so long,
and withstood such extreme events? As a group, beetles have proved remarkably
adept at adapting to ecological changes.
Fossil records show that beetles were abundant during the Mesozoic (about 200
million years before present). Beetles were flower visitors of the earliest angiosperms.
Many present-day beetle pollination associations like that of Magnolia, a primitive
woody angiosperm, have ancient evolutionary origins.
Beetles were among the first insects to visit flowers and they remain essential
What is cantharophily?
Very few plants are primarily pollinated by beetles. Those that are dependent on
beetles are called cantharophilous plants. The process of beetle
pollination is called cantharophily. Cantharophilous flowers share several
Typically the flowers are bowl-shaped with exposed sexual organs.
Flowers are white to dull white or green and have a strong fruity odor.
The flower structure is usually simple, with no distinction between the petals
A moderate amount of nectar may be produced by these day-opening flowers.
The flowers are usually radially symmetrical and may be large and solitary,
such as magnolias and water lilies, or they may be clusters of small flowers,
like goldenrod and composites.
Descriptions of beetle pollination sound repugnant to us clean-loving humans. The
beetles eat their way through petals and other parts of the flower. Then they defecate
within the flowers and roll around in it as they relish the pollen inside. This is why
they are sometimes called “mess and soil” pollinators.
Pollinating beetles are not searching for nectar; for them the reward is pollen. Beetles
believed to provide pollination include members of several beetle families: soldier,
jewel, blister, long-horned, checkered, tumbling flower, scarab, sap, false blister, rove,
and many other types of beetles.
Basic beetle anatomy.
don’t have bones and an internal skeleton like we
do. They have an exoskeleton that is like a large shell. It protects them and gives
them shape. Tiny hairs called “setae” on the outside of the exoskeleton help improve
the beetle’s perception of touch and sound.
Eyes: Beetles have
“compound eyes.” Each eye is made up of many
units called “ommatidia”. There can be thousands of ommatidia in a single beetle eye.
Through the ommatidia, beetles see in patterns of light and dark dots.
are very important to beetles, as they provide
constant information about touch, smell and taste. Beetles use taste and smell
receptors on their antennae to locate food and also to identify pheromones.
Mountain pine beetle need strong mouthparts to be
able to chew through bark and phloem. Their mouthparts move in a cutting motion
Thorax: The thorax
is the middle body region – between the head
and the abdomen – that serves as an attachment point for the legs and wings. This
is where the heart is located which pumps blood toward the front of the body. Blood
does not circulate through vessels, but passes freely between and around body
organs. The thorax itself is composed of 3 segments, with a pair of legs located on
each segment and 2 pairs of wings found on the second and third segment. The thorax
is where the muscles are located that help the beetle walk, jump and fly.
Legs: Adult beetles
have 6 legs. Each of the segments of the thorax
bears 1 pair of legs. The legs are jointed, and the last segment of the leg bears a small
Wings: The beetle has
two pairs of wings found on the second and
third segment of the thorax. One pair is the hard-shelled outer wings called the
“elytra”. These are not used for flying, but to protect the beetle’s flying set of wings
and its body as it crawls through narrow passages and tunnels in a tree. The second
set of wings is membranous or see-through, and is folded under the elytra when not
Abdomen: The abdomen
is the posterior or last of the three body regions
in the mountain pine beetle. It is the biggest body part and is composed of 11
segments. The abdomen holds the beetle's digestive system and reproductive
organs, and is also where beetles breathe! Beetles don’t have lungs like mammals
do – instead they breathe through a series of holes in their abdomens called
Beetles inhabit nearly every ecological niche on the planet. This group includes
some of our most beloved bugs, as well as our most reviled pests. Here are 10
fascinating facts about beetles, our largest insect order.
Beetles are the largest group of living organisms known to science, bar none. Even
with plants included in the count, one in every five known organisms is a beetle.
Scientists have described over 350,000 species of beetles, with many more still
undiscovered, undoubtedly. By some estimates, there may be as many as 3 million
beetle species living on the planet. The order Coleoptera is the largest order in the
entire animal kingdom.
You can find beetles almost anywhere on the planet, from pole to pole, according
to entomologist Stephen Marshall. They inhabit both terrestrial and freshwater
aquatic habitats, from forests to grasslands, deserts to tundra, and from beaches
to mountaintops. You can even find beetles on some of the world's most remote
Research has shown that beetles are capable of seeing color, but they mainly rely
on their sense of smell for feeding and finding a place to lay their eggs.