Introduction of the Japanese beetle into North America
Cover of Dreer’s Garden catalogue featuring Japanese iris, the likely source of introduction of the Japanese beetle into Dreer’s nursery and North America.
In 1916 New Jersey agricultural inspectors discovered the Japanese beetle in North America for the first time. It had established a population in a commercial nursery. Entomologists soon recognized the potential of this beetle to become a pest. Henry A. Dreer, the nurseryman responsible for importing this beetle, dismissed the beetle’s danger and opposed efforts to control it. His denial of the science likely contributed to the failure of entomologists to eradicate this pest from North America before it irreversibly escaped outside the nursery.
Japanese beetle and ant feeding on porcelain berry (Ampelopsis brevipedunculata).
The beetle’s larvae in the form of grubs fed on roots of grass. They spoiled lawns, golf courses and pastures. Above ground, the adult beetles defoliated orchards, ornamental trees, shrubs, and crops. The larvae could number as many as 1,500 per square yard. Sixty bushels of Japanese beetles were collected from one orchard in a single day.
The Pennsylvania Department of Agriculture recommended treating infested soil with lead arsenate at a dose of 1500 pounds per acre. To protect vegetation from the adult beetles in one Philadelphia suburb, 4 ½ tons of lead arsenate were sprayed on trees and shrubs.
Although the plague subsided in Philadelphia by the end of the 20th century, the Japanese beetle remains common. It has recently been ranked as the worst pest of turf, landscapes, and nursery crops in the eastern United States. Lead arsenate deployed as an insecticide against the pest a century ago persists as a soil contaminant. The story of the establishment of the Japanese beetle in North America is a reminder of the need for independent oversight of nurseries.
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