This article is about the Ladybug Miraculous. You may be looking for another Ladybug or Miraculous.
I used to think that maybe [Ladybug] was a scientist who got stung by a radioactive ladybug while strolling at the Cité des Sciences. But the more I think about it, the more I believe it's actually the earrings that help Ladybug to transform, so the whole bug-bite theory kind of went out the window.
In general, the earrings are circles with a smooth surface and a silver lining. In camouflage mode, the earrings are black. However, in charged mode, they become red with five black spots in a quincunx pattern. As the earrings start running out of power, they make a beeping sound, and the dots start disappearing one at a time as an indication of how much time (one dot is equivalent to one minute) Marinette (or another Ladybug Miraculous holder) has left.
In "Reflekdoll," when Adrien isn't Mister Bug, the earrings are silver.
The Ladybug Miraculous grants its wielder incredible powers of speed, endurance, and strength. Its special weapon is an unbreakable yo-yo, which can be utilized as both a weapon, a communicator, and an object that can be used to breathe underwater. Its special superpower is called the Lucky Charm, giving the user the ability to create a useful arbitrary object in order to obtain their goal, like defeating a villain. As long as the superpower isn't used, the wielder can remain transformed indefinitely. However, as soon as the superpower is used, the wielder loses power and the transformation wears off in about approximately five minutes. The earrings also have the ability to give the wielder the costume they truly desire.
The Ladybug Miraculous can also purify anything “corrupt or malignant”.
Using the yo-yo, the holder traps the infection, an infected creature, or an infected object, so the yo-yo cures it. When the yo-yo opens, the infection is gone, and if there was an infected animal or object, it is healed or clean. The person can use the Miraculous' purification power on various things, like akumas created with the Butterfly Miraculous or an unknown black substance, as seen in fourth issue of Miraculous Adventures.
The other power is the Miraculous Ladybug (superpower). If there is damage caused by a villain or Cat Noir's Cataclysm, the holder throws the Lucky Charm object in the air and says Miraculous Ladybug, a restoration power using a swarm of magic ladybugs repairs all damage in an instant. The restoration power is also capable of healing those who are hurt by villains or their own powers.
If the Ladybug Miraculous and Cat Miraculous are used together while also using a special invocation, the holder will achieve ultimate power. The person wielding them can make a wish that can alter reality. However, because the universe must maintain balance, every action has a reaction; for instance, a wish to become human would result in someone losing their humanity.
It could be possible that any user of the Ladybug Miraculous can use any Lucky Charm to summon the Miraculous Ladybug (superpower) even if they didn't summon the object, as seen with Ladybug in "Sandboy". Also seen in "Weredad" and "Miraculer", if the holder can't use the Miraculous Ladybug (superpower) as the result of having no Lucky Charm, the power can be activated by using the yo-yo.
After Tikki consumes one of several special potions or an eatable made with one, and the wielder transforms, they are able to unlock power-ups, an additional specific ability granted by each potion. So far, only seven potions have been shown, each with a unique color:
The green-blue potion transforms Tikki into "Aqua Tikki", which grants the wielder the ability to breathe underwater and improve their swimming capability with flippers added on the feet.
The light blue potion transforms Tikki into "Stalac Tikki", which grants the wielder ice-related abilities, and the suit gains a pair of skates to move freely on ice. In this form, the round spots on the suit and the yo-yo change into hexagons.
In the theme song, the Ladybug Miraculous are in the raised center of the Miraculous jewelry box with the Cat Miraculous, both of their sections creating a yin-yang symbol inside the box.
The Ladybug Miraculous is in the yin section (like in every yin-yang symbols, there’s also both of them in each). Some of the things that yin represents are coldness, darkness, passiveness, and intuition (which interprets the Cat Miraculous).
Ladybugs are known to be symbols of good luck, protection, and love.
Ladybug's legacy is over 5,000 years old, as revealed in "The Pharaoh" and also dates all the way back to Ancient China.
Both the Ladybug Miraculous and the Goat Miraculous are so far the only known Miraculouses that have two pieces.
The user needs to be wearing both earrings for the transformation to work. Although it is unknown if the transformation works with just one.
As seen in "The Dark Owl", if one of the earrings is taken, the suit will slowly dematerialize, though the Yo-yo remains.
When the left earring was taken, the dematerialization began with the right side of the mask and the right hand, showing Marinette's bare skin.
In "Troublemaker", the left earring was taken, and the dematerialization began with the left side of the mask, both forearms, and both shins. Additionally, a high pitch beeping was emitted from the earrings. As the suit dematerialized, Marinette's body, excluding the face, was covered with pink energy. When the earring was returned, the missing parts completed themselves, and the beeping stopped.
In the early concept for the series, including before kwamis were created, the earrings gave pure luck to its wearer. However, as Thomas Astruc explained, "it only works when [the wearer uses] it for others. Otherwise, it backfires."
Because broadcasters believed pure luck as power was "too abstract for kids," Thomas figured out a different superpower, Lucky Charm. 
The design of the earrings was different in the Ladybug PV and early CGI animation. In them, the earrings had gold outlines around the edges of the earring and the black spots.
In "The Pharaoh", Ladybug gives Pharaoh a fake pair of earrings that more closely resemble the earlier design.
Thomas Astruc stated that he might include previous Ladybugs into the show if he finds a good story for them.
Like for the Ancient Egyptian Ladybug in "The Pharaoh" or when Tikki mentions of the past Ladybugs in "Befana".
For a staged battle for Mr. Damocles as the Owl in "The Dark Owl", Marinette creates a fake replica of the Ladybug Miraculous, which she later uses to trick Mr. Damocles' akumatized form and Hawk Moth.
In the NYCC 2016, the Ladybug Miraculous seems to have other magical abilities. These abilities seem to be related to objects known as Stones and Pearls.
Stone of the Sun - Flying power
Pearl of the Mysteries - Infinite Lucky Charms
Pearl of the Heart - Cure the akumatized
Pearl of the Sea - Breathe and swim underwater
Stone of the Moon - Fly and breathe in space
However, Thomas later confirmed on Twitter that the Pearls and Stones are a concept that won't be featured in the show anymore. The Pearl of the Sea power was replaced by the green Miraculous potion.
So far, only one male, Micazoyolin, is known to have wielded the Ladybug Miraculous, thus, followed by Mister Bug.
The Ladybug Miraculous users are the only ones who can purify akumas.
In "Kwamibuster", in order to defeat the titular villain and to save the kwamis she had captured, Multimouse (Marinette with the Mouse Miraculous) combines the Ladybug Miraculous with hers, becoming Multibug.
The Ladybug Miraculous is the Miraculous with the second most combinations, following the Mouse Miraculous, with two: the Mouse Miraculous and Dragon Miraculous.
In "Reflekdoll", after an incident causes a mix up of the Miraculous, Adrien Agreste uses the Ladybug Miraculous to turn temporarily into Mister Bug.