Over a million species of insects have already been discovered, and the Royal Entomological Society estimates that there may be as many as another 10 million species still to be discovered. Insects are the world’s largest group of organisms and the most diverse. I wanted to find out how different insects feed.
Insects either use their jaws to bite and chew their food (such as dragonflies) or suck it up using a proboscis (like a butterfly.) The housefly uses sponging to soften the food with saliva before absorbing the liquid food.
In this article, I look at the different feeding methods for insects and a few other insects to see how they feed.
There are two main types of feeding categories that insects fall into. Insects such as ants are chewers, which can be seen by the holes they leave in plants. Grasshoppers, dragonflies, and beetles also fall into this category, using their jaws to bite into their prey. Many insects feed not just on plants but also other insects.
Suckers are the second category of insects. Mosquitoes fall into this category as they use their beak to suck blood from animals. Aphids also fall into this category as they extract food from plants.
Insects can also be divided into two categories according to their life cycles, reflected in their food-finding method.
Insects fall into these two categories. Some insects, such as butterflies, transform by completing a metamorphosis through several stages. In butterflies, this occurs when they change from eggs to larvae before entering pupae and emerging later as a butterfly.
The process is gradual, and the way they feed goes through several stages. The larvae do feed, but the pupae do not. When the butterfly emerges, they do provide.
Insects that do not go through this complete metamorphosis resemble small adults when young, and these feed in the same way and have a similar diet throughout their lives.
This shows that although insects are chewers or suckers, they may change as they go through metamorphosis.
Here are some examples of how different insects feed.
The froghopper or meadow spittlebug causes small amounts of foam, sometimes called cuckoo spit, to appear on plants in May and June. These tiny insects push their style into the plant after hatching from these small eggs until it finds the water-conducting vessel in the plant, the xylem.
The young insect (nymph) then extracts water from the plant, which passes through its alimentary canal and leaves the body as foam. The spirit then lives in the foam, protecting it from predators.
There are small amounts of nitrogenous nutrients in the plant solutions, and the froghopper nymph uses this as food in the foam until the nymph molts and emerges as an adult. Once they leave the foam, the adults feed less often, and the foam dries up.
Another insect that uses a style to suck nutrients is the cabbage aphid. They push the class into the plant’s phloem, which houses the energy and nutrient supplies. Large amounts of sugar are in the phloem, and the aphids can extract this. The sugar passes through the aphid’s body and is excreted as sugary honeydew. This can e found on the leaves of trees when summers are dry.
Cabbage aphids can be a pest to farmers as they only live on cabbage plants and related plants. When there is a heavy infestation of cabbage aphids, they can drain the plant’s energy and nutrients. Once the supply runs out, the aphids will move to the next plant.
Insects find their mates in some unique ways. Please find out more in this article I wrote.
Wasps feed on nectar and other liquid food, such as the juices from rotting fruit or the honeydew left behind by the cabbage aphid.
The larvae develop in the nest, so adults need to supply food to the larvae. A well-established colony of wasps may contain thousands of cells, so workers will attack and kill caterpillars, flies, spiders, and butterflies to feed the larvae.
The seven-spotted ladybird lays small clusters of yellow eggs near aphid colonies. Once the ladybirds have hatched, the larvae move to the nearest aphids and start eating them. As long as enough aphids are eaten, the larvae grow, forming orange and black pupae attached to plants.
The seven-spotted butterfly larvae are actual cannibals, however. If the supply of aphids dries up, then they will attack and feed on each other.
Once they become adults, the seven-spotted ladybird continues to eat its diet of aphids but will fly off long distances to find food if needed.
A genus of flies does another way of feeding. Although the adults feed on flower nectar, the larvae are parasitic. The eggs are laid in the lining of birds’ nests during incubation. The larvae will usually hatch at the same time as the young birds and attach themselves through a sucking disc to the underneath of the young birds.
The larvae use their mouth hooks to pierce the bird’s stomach, sucking the blood out. They hide amongst the nest material, and it is thought that more than one hundred larvae may be found in a single bird’s nest.
The white-lined sphinx moth goes through a complete metamorphosis, and the larvae feed differently from the adults. The caterpillars will feed on the leaves of tomatoes, grapes, willow weeds, elm, and other plants. The caterpillars will consume significant amounts of leaves as it is not very nutritious.
In winter, the plant’s energy and nutrients allow the transformation into a moth. The white-lined sphinx moth feeds at night and uses its beak to suck the sugar nectar from pale or white flowers, as these stand out against the rest of the foliage.
The white-lined sphinx moth is also known as the hummingbird moth as they hover in front of the flow, extracting all the nectar before moving on to the next flower.
Dragonflies do not suck their food but use their jaws to bite. They outfly their prey and then deliver a few bits to kill them. Dragonflies feed on other insects and even smaller dragonflies.
Dragonflies, more significantly, live in water and will eat almost anything smaller than themselves. Larger dragonfly larvae are also known to eat small fish. The larvae live underwater, undergoing a series of molts as they age. Once the final skin splits, the adult dragonfly emerges.
Houseflies use a method called sponging to get their food. Houseflies do not have jaws, so their mouths absorb food like sponges. Houseflies can only eat liquid food. Houseflies release saliva, which is regurgitated from their stomach onto the food, which then dissolves it. They then use their straw-shaped tongues to absorb liquid food. Houseflies taste with their feet.
Bryan Harding is a member of the American Society of Mammalogists and a member of the American Birding Association. Bryan is especially fond of mammals and has studied and worked with them around the world. Bryan serves as owner, writer, and publisher of North American Nature.