This festival aims to increase tourism, promote culture and preserve traditions.
Provincial deputy governor Kritphet Petchaburanin presided over the opening ceremony on Saturday with thousands of local residents, as well as Thai and foreign tourists, attending the event.
The festival features a caravan of massive rhinoceros beetles, an exhibition of local lifestyles, beetle fights and contests. Locally made products, primarily clothing and agricultural products, are also on sale.
On October 8, rhinoceros beetles will be reintroduced to forests to ensure the survival of the species.
Some local residents refer to the beetles as "Maeng Kham" due to their penchant for fighting. They are also dubbed "fighters of the mountains" because their battles can last for more than one hour.
Rhinoceros beetles have a life cycle of one year, and mate between August and November. They consume tree sap and people raise them by feeding them sugarcane, bananas and melons.
In Thailand, small beetles with short horns are called "Kwang Ki", medium ones with medium-length horns are called "Kwang Sam", and large ones with long horns are called "Kwang Song". Females without horns are called "Emo" or "Elum".