Callery pears: An invader ‘worse than murder hornets!’

Stinky but handsome and widely popular landscape trees have spawned aggressive invaders, creating thickets that overwhelm native plants and sport nasty four-inch spikes.

Bradford pears and 24 other ornamental trees were developed from Callery pears — a species brought to America a century ago to save ravaged pear orchards. Now, their invasive descendants have been reported in more than 30 states.

“Worse than murder hornets!” was the tongue-in-cheek title of a U.S. Department of Agriculture webinar in 2020 about Callery pears including the two dozen thornless ornamental varieties sold since the 1960s.

“They’re a real menace,” said Jerrod Carlisle, who discovered that four trees in his yard and one at a neighbor’s had spawned thousands on 50 acres (20 hectares) he was turning from cropland to woods in Otwell, a community of about 400 in southern Indiana.

Indiana is among 12 midwestern and western states that have reported invasions, though most are in the