Many people use the terms bug and insect interchangeably. While it may seem like a matter of preference, there are several differences between the two. Moreover, the term “bug” isn’t a precise way of describing many creatures we call bugs, like beetles. In this article, we’ll outline and discuss several ways to differentiate beetles vs. bugs. When we’re finished, you’ll know many ways that they are unique and why it’s only fair to classify them differently.
Comparing Beetles and Bugs
|Phylogenetic Family||– Insecta class |
– Coleoptera order
|– Insecta class |
– Hemiptera order
|Morphology||– Have forewings and hindwings|
– Some forewings are soft, and some are hard
– Possess forward-facing or downwards mouthparts, including mandibles to grasp, cut, or otherwise crush
– Mouthparts used for gathering food and defense
– Have a hard exoskeleton
– Compound eyes
|– Have specialized mouthparts called proboscis that allow them to suck fluids |
– This straw-like structure that helps them drink is not retractable
– Four wings, an outer and inner pair
– Outer or front pair of wings are leathery at the base and membranous at the end
– Under or rear pair of wings are membranous
– Compound eyes
|Metamorphosis||– Four stages of life |
– Egg, larva, pupa, adult
– Most beetles lay eggs that hatch into larvae, often worm-like
– Larva feed a great deal, but the larval forms vary in looks
– Beetle larvae are known for their chewing mouthparts and spiracles
– Larva undergo instars, developmental stages between molts
– Some species build chambers out of feces and begin their pupal stage
– They emerge from the pupa as an adult
|– 3 Stages of life |
– Hatch from eggs to become nymphs and then molt to become adults
– No larval metamorphosis
– Referred to as an incomplete or gradual metamorphosis
|Number of Species||– Over 350,000 species of beetles have been described |
– Some scientists estimate that over 1 million species of beetles exist
|– Roughly 80,000 species|
|Examples||– Rhino beetle, stag beetle, Hercules beetle, dung beetles, jewel beetles||– Stink bugs, bed bugs, wheel bugs, cicadas|
The Key Differences Between Beetles vs. Bugs
The greatest differences between beetles and bugs can be found in their phylogenetic families as well as their metamorphoses. Specifically, beetles are from the Coleoptera order of the Insecta class, but bugs are from the Hemiptera order of the Insecta class.
Beetles undergo a four-stage life cycle where they are an egg, larva, pupa, and then an adult with a complete metamorphosis. Still, bugs undergo incomplete metamorphosis with three life stages: eggs, nymphs, and then adults.
We’ll go into greater detail regarding the metamorphoses of these two orders of insects, along with other differences that set them apart.
Beetles vs. Bugs: Phylogenetic Family
Beetles and bugs have significant differences in their phylogenetic families. Specifically, beetles are from the Insecta class, and so are bugs. However, beetles are from the Coleoptera order of insects, but bugs are from the Hemiptera order of insects. Thus, the two classes are somewhat closely related through their phylogenetic class, but they come from different orders.
Beetles vs. Bugs: Morphology
Beetles and bugs have many similarities in morphology, but they also have some differences. For example, both of these creatures have forewings and hindwings. Both only use the rear pair to fly, and they are membranous. However, the outer wings of beetles are hard, but those of bugs are leathery at the base and membranous toward the ends.
Both beetles and bugs have compound eyes and an exoskeleton that protects their body. However, the mouthparts of these creatures are very different. Beetles have forward-facing or downward-facing mouthparts that include mandibles. These structures are used to grasp, cut, and crush food, but they’re also used for defense.
Meanwhile, bugs have some very specific mouthparts like their proboscis, a structure akin to a straw that allows them to suck fluids. Thus, if you see an insect with mandibles, it’s not going to be a bug, but it also might not be a beetle.
Beetles vs. Bugs: Metamorphosis
Beetles have four stages of life that include a complete metamorphosis, but bugs have three stages of life with an incomplete metamorphosis. Beetles start as eggs and then transform into larvae, pupae, and finally, their adult form. Bugs hatch from eggs to become nymphs and then repeatedly molt to reach their full adult size.
Beetles larvae are worm-like, and they differ from most bugs’ nymph forms a great deal. Beetle larvae are known for their chewing mouthparts and spiracles.
They’re also known for their instars, the developmental stages that they undergo between molts. These larvae are voracious eaters while they grow. Eventually, they build a pupal chamber, often out of feces, and undergo their pupal stage before emerging as adults.
Meanwhile, bugs do not have a larval metamorphosis. Instead, they hatch from eggs into a nymph form and continue to undergo molts in an incomplete or gradual metamorphosis as they reach their adult form. These differences in the metamorphosis processes between these creatures make it easy to tell them apart.
Beetles vs. Bugs: Number of Species
Far more species of beetles exist compared to bugs. Over 350,000 species of beetles have been identified, and some estimate that the number could be much higher, over a million species! However, only 80,000 species of bugs have been identified so far. In short, there are far more beetles around than bugs.
Beetles vs. Bugs: Examples
It may not be hard to imagine different types of beetles, such as the rhino beetle, stag beetle, Hercules beetle, flea beetle, dung beetle, and jewel beetle. Meanwhile, bugs are more difficult because some creatures with “bug” names are not actual bugs. Real bugs include stink bugs, bed bugs, wheel bugs, and cicadas.
Telling bugs and beetles apart at a glance may be somewhat difficult since they have some morphological similarities. Yet, if you can get a closer look at them, especially their mouthparts and wings, it’ll be easier to differentiate them. You can also consider their metamorphosis. If you see a creature in a cocoon or pupal chamber, the chances are that it’s not a bug.
Entomology is a rich field, and a deeper understanding of their studies could yield easier methods to tell a beetle from a bug.
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