South Korea’s Ministry of Environment has named the giant water bug, known as Lethocerus deyrollei, as May’s endangered wildlife species of the month. (Image courtesy of the Ministry of Environment of Korea)
SEOUL, May 1 (Korea Bizwire) — South Korea’s Ministry of Environment has named the giant water bug, known as Lethocerus deyrollei, as May’s endangered wildlife species of the month, highlighting the insect’s rare and remarkable paternal behavior and its declining habitat.
Once common across the country, the water bug has become increasingly rare due to the destruction of wetlands and the overuse of pesticides. It was officially listed as a Class II endangered species in 1998 and now survives only in isolated habitats — including parts of Jeju Island, the western and southern coasts, and restricted military zones.
Belonging to the aquatic Hemiptera order, the giant water bug measures 5 to 7 centimeters in length and 2 to 3 centimeters in width. It is a top predator in freshwater ecosystems, feeding on other insects, small fish, amphibians, and reptiles. Its front legs are shaped like sickles to grasp prey, and it digests food externally by injecting enzymes and then absorbing the liquefied protein.
Unlike most insects, the male water bug assumes full responsibility for egg care — a rarity in the insect world. After mating in late spring, the female lays clusters of 60 to 100 eggs on aquatic plants above water. The male then tends to the eggs for about ten days, hydrating them with water droplets and shielding them from the sun. In a surprising twist of evolutionary behavior, males even defend the eggs from females, who may attempt to consume or remove them.
Scientists view this behavior as an evolutionary strategy to maximize offspring survival. To become dominant predators, juvenile bugs must grow large — which requires starting life from oxygen-rich, larger eggs laid outside of water. By freeing the female from parenting duties, she can consume more nutrients and allocate energy toward future reproduction.
The Ministry’s selection of the water bug aims to raise awareness of both the ecological significance and fragility of freshwater habitats. With only fragmented populations remaining, conservation efforts are increasingly urgent to preserve this unique aquatic species and the biodiversity it supports.
Lina Jang (linajang@koreabizwire.com)
