Grounded is a difficult game, and progression is pain. While peaceful by default, even the Ladybug is a formidable "boss" initially, with its ton of life, pain attacks, and forward charge. You risk dying a bunch of times before you get to the end of it.
It is however important to kill a ladybug fairly quickly, since a quest from BURG.L asks you to do so, and the materials collected from its corpse are mandatory to create the level 2 tools. The ladybug's armor is also fantastic for gain survivability and block damage.
From a distance
This is by far your best option for killing ladybugs, as long as you don't have great gear. For this, you need a bow, which requires going to farm gnats. You're also going to need a BIG supply of arrows. Allow at least 120-150 to avoid running out of them to complete it. It will take up space in the bags. Also plan some bandages and improvised strings to repair your bow if necessary. For the armor, we recommend the torso and the legs of the acorn armor, and the grass eye patch for the head, since it gives an attack bonus. Normally, you won't get hit, but an accident can happen quickly.
All that remains is to locate a ladybug, and a high place on which you can climb, such as a branch or a large rock. Avoid the grass and the clover, the ladybug will demolish them, and you with it. It's important that your stance is high enough, since the Ladybug's charge and roar can sometimes hit quite high, which could kill you (like in the video). All that remains is to shower the ladybug with arrows, from your hideout, until death ensues. This will take a few minutes.
An important detail is that the pressure must not be released during the attack. If the ladybug passes out of combat, it will quickly regenerate its life. However, you have time to regenerate your stamina after completely depleting it. This will help you unlock one of the mutations faster, as a bonus.
Once the ladybug is dead, remember to collect all your arrows.
In melee
Confronting the ladybug in melee is possible, but it is a dangerous exercise. You need full acorn armor, and preferably a shield. Plan a stock of bandages, and drink a smoothie before the fight. Performing perfect blocks on his attacks gives you great opportunities to counterattack, but it takes practice, and not everyone is able to react in time. Spinning around the ladybug and using obstacles to regenerate your stamina and life is then necessary. But be careful, if you don't attack the ladybug regularly, its life will regenerate, which will make the fight even longer and more difficult.
Fighting in melee is a better option in multiplayer, since it allows you to have one or two tanks, while the other players attack from a distance, or with other more powerful weapons.
With ants
An easy way to kill ladybugs is to head to the red anthill, northwest of the first scan site. There are plenty of very aggressive soldier ants on site, which automatically attack anything that passes by. Ladybugs often pay the price. You can also attract several soldiers then take refuge behind the ladybug, in order to initiate the fight. It is an easy source of ant and ladybug materials. All that remains is to finish off the survivors.