Biting katydids spread in Seoul area as lovebugs fade

While the nuisance of lovebugs has subsided in Seoul and nearby cities, residents are now contending with a surge in brown katydids. Large numbers of these insects, scientifically known as Paratlanticus ussuriensis, have been observed in areas like Mount Buram and Mount Surak in northeastern Seoul, as well as in Namyangju, Gyeonggi Province. Online posts from residents describe the katydids appearing on hiking trails, apartment walls, and even inside homes.

Brown katydids are native to Korea and grow to about 3 to 4 centimeters as adults. They possess brown bodies and strong hind legs that enable them to jump considerable distances, leading some to mistake them for camel crickets. Beyond being a nuisance, these insects can pose a threat to agriculture when their populations boom, damaging fruits such as peaches, plums, grapes, and apples, particularly in orchards near mountainous regions.

Experts advise against handling or attempting to catch brown katydids due to their strong jaws, which can inflict bites if the insects feel threatened or are provoked. The current increase in their activity aligns with their typical peak season in July and August. These insects hatch in spring and early summer after overwintering as eggs underground.

Environmental factors, specifically changing temperatures, are being cited as a potential cause for the heightened katydid activity. A study by the Rural Development Administration indicated that a 2.5-degree Celsius rise in temperature could boost the egg-laying rate of brown katydids by 58 to 68 percent. Their eggs also have the capacity to remain dormant for over two years, allowing for sudden outbreaks when conditions become favorable. The expanding range of their activity is suggested by recent sightings around Seoul, following past crop damage in other provinces.