Dive into the world of jewel bugs (Scutelleridae) and uncover their stunning colors and patterns. Learn about their unique defense mechanisms and why they’re essential to our ecosystem. Get ready to be amazed by nature’s miniature masterpieces!
Phylum: Arthropoda
Class: Insecta
Order: Hemiptera
Suborder: Heteroptera
Infraorder: Pentatomomorpha
Superfamily: Pentatomoidea
Family: Scutelleridae
Jewel bugs are vibrant
Jewel bugs, also known as shield-backed bugs or metallic shield bugs, belong to a group called true bugs. They’re often mistaken for beetles because their thoracic scutellum, an extension of the thorax, forms a shield that covers their abdomen and wings. This sets them apart from most other bug families within Heteroptera like stink bugs (Pentatomidae).
The Scutelleridae bugs stand out because of their stunning appearance. They come in bright colors with a shiny, metallic look that changes when you look at them from different angles. Some have patterns like spots or patches. However, among the roughly 450 jewel bug species worldwide, not all are colorful. Some are rather plain in color and prefer to hide, making them hard to spot.
The species are really good at copying the colors and patterns of other bugs or animals to protect themselves. Some types even copy the bright colors of their pals to scare off enemies.
These Scutelleridae bugs are oval-shaped and come in small to medium sizes, usually ranging from 5 to 20 millimeters long. They’ve got triangular heads, three to five-part antennasm, and setose sternal glands. These special glands are under their bellies covered in tiny hairs.
Habitat
The Scutelleridae bugs can be found all over the world, from Europe and Africa to Australia and Asia. For example, the Picasso bug is native to parts of Africa, including countries like Ethiopia, South Africa, and Cameroon. On the other hand, the cotton harlequin bug inhabits northern and eastern Australia, New Guinea, parts of Indonesia, and some Pacific islands. These terrestrial insects live in a variety of habitats, including grasslands, forests, and coastal vegetation.
Diet
Jewel bugs are primarily herbivorous. They are known to feed on a wide range of plants, such as ferns, Lantana, figs, and the shrub Breynia oblongifolia. Their diet also includes plants of economic importance, which can sometimes make them seem like pests. But really, they’re not a big problem because the plants they munch on aren’t super valuable.
To eat, these species inject special enzymes from their saliva into the plants. These enzymes help break down the plant material into a liquid that they slurp up.
They release chemicals
Metallic shield bugs have a range of predators like birds, insects, and other critters that snack on bugs. Even predatory insects like mantids can eat them.
To protect themselves, the Scutelleridae bugs apply many strategies, from the look to the smell. The jewel bugs with dull colors can blend into the surroundings, making themselves invisible. On the other hand, colorful species use their vibrant colors as a warning, telling predators that they may taste bad or toxic. These flashy colors can confuse enemies. Research in Queensland found that harlequin bugs use their bright colors to scare off birds. Interestingly, while we can easily distinguish their bright hues from green foliage, praying mantises struggle with this. They can’t tell apart the bug’s orange from the green of leaves.
Like the notorious stink bugs, these Scutelleridae bugs can unleash a stinky smell to fend off predators. This odor comes from special glands and is let out when the bug feels in danger, serving as a smelly defense mechanism.
Besides their looks and the chemicals they release, they also gather in groups to defend themselves. When they huddle together, the smell of their chemicals gets stronger, warning of potential threats. If that doesn’t work, they might fly away or fall to the ground to escape danger.
Some jewel bugs take it a step further by mimicking the look of other insects that predators find gross or poisonous. This extra trick makes predators think twice before attacking.
Life cycle
Jewel bugs go through three main stages in their life cycle: egg, nymph, and adult. First, the female lays eggs in groups on plants. These eggs start off white or cream-colored but may change color as the baby bugs inside grow.
After 7 days, the eggs hatch into nymphs. These young bugs look like adults but are smaller and don’t have wings yet. During this stage, some species, like the green jewel bug, might huddle together when it’s dry. Some Scutelleridae bugs even take care of their eggs and young nymphs.
As the nymphs grow, they shed their skins several times, usually about five times, before becoming adults. The lifespan of an adult jewel bug is no more than a month.
