June beetle , June bug Meaning, Definition & Usage

Definitions
  1. (Zoöl.), any one of several species of large brown beetles of the genus Lachnosterna and related genera; so called because they begin to fly, in the northern United States, about the first of June. The larvæ of the June beetles live under ground, and feed upon the roots of grasses and other plants. Called also May bug or May beetle.

Webster 1913