How large can giant water bugs grow?

Giant water bugs, which belong to the family Belostomatidae within the order Heteroptera, are the largest insects in that order. Their size varies significantly based on their environment:1

• In northern climates, they typically range between 2 and 5 cm (about 0.8 to 2 inches) in length.1
• Certain South American species, such as Lethocerus grandis, can grow to exceed 10 cm (4 inches) in length.1

These predatory insects are well-adapted for their aquatic environment, featuring oarlike hind legs for swimming and front legs specialized for grasping prey, which can include small fish, tadpoles, and salamanders.1