In a recent journal published in Entomological Science, Dr. Shin-ya Ohba shares the unusual behavior and role reversal of a giant water bug becoming the predator and eating a juvenile turtle in a ditch in central Japan. While this Kirkaldyia deyrolli, or giant water bug, from the Lethocerinae family has been seen preying on small vertebrates such as frogs and fish, Ohba has captured images of the bug eating small turtles and snakes.
The K. Deyrolli is a native bug from Japan and is listed by the Japanese Environment Agency as an endangered species. They live primarily in the rice fields throughout Japan and feed on small frogs and fish. These bugs can grow up to 15cm long and inflict a venomous bite. They have been known to occasionally bite humans, causing a burning pain that lasts for several hours.
Ohba was conducting a night sampling in the central Japan region of western Hyogo when he recorded images of the giant water bug feeding on a small Reeves pond turtle. The insect used its front legs to hold on to the turtle while it inserted its rostrum into the prey in order to feed. While the bugs are known for only attacking moving prey, Ohba assumes that the bug caught and killed the turtle before he stumbled upon it.
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More information: Field observation of predation on a turtle by a giant water bug, Entomological Science, DOI: 10.1111/j.1479-8298.2011.00450.x
The giant water bug, subfamily Lethocerinae, which has the largest body size among Belostomatidae, is known to be a vertebrate specialist that preys upon fish, amphibians and snakes. However, there have been no reports concerning predation on a turtle by Lethocerinae. Here, I report that a male giant water bug Kirkaldyia (Lethocerus) deyrolli (Heteroptera: Belostomatidae) (58.09 mm in total length) was catching hold of a turtle Chinemys reevesii (34.14 mm in carapace length) in a ditch adjoining a paddy rice field. This is a first report of K. deyrolli eating a turtle.