Broad-Necked Root Borer (Prionus laticollis)
Detailing the identifying qualities of the Broad-Necked Root Borer, including physical features and territorial reach.
Updated: 2/9/2018; Authored By Staff Writer; Content ©www.InsectIdentification.org
The giant size of female Broad-Necked Root Borer Beetles and the fierce jaws of the smaller male give this species an unfortunately menacing appearance to humans.
This forest-dwelling beetle is at home in the eastern part of the continent. The 'neck' of the Broad-Necked Root Borer is quite wide and has small spikes along the sides. The body is black, but it may look like dark brown as well. In stark contrast to the dark overhead view, the ventral (belly) side of the abdomen is yellow. Females are mammoth in size. They are more than two times larger than males and because of their heft, they are unable to fly even though they have wings. In fact, this genus is as large (by weight) as Rhinocerous Beetles. The smaller male can fly, albeit noisily. Males have large mandibles making their jaws look like they could deliver a terrible bite. Typically, male beetles reserve use of these jaws for territorial battles with other males.
Broad-Necked Root Borers are most active in the summer months and can be see crawling on logs or the forest floor. Females deposit fertilized eggs into the soft earth using a syringe-like ovipositor. The eggs hatch and the larvae continue to dig deeper into the soil to find their food source: roots from trees and shrubs. They continue to feast on trees as they grow, consuming the inner bark and tissue for years before emerging as adults in the summer. Look for the Broad-Necked Root Beetle near woods and forests though it has been seen crossing parking lots between habitats. If this type of beetle has made a home near buildings, it is attracted to lights at night and has a propensity to hit windows reflecting light with a loud bang.