Spotted Lanternfly confirmed at multiple locations across the watershed

July 30, 2026Boston Basin

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(Lycorma delicatula) have been confirmed at multiple locations across the watershed over the past two months — 28 iNaturalist observations from Watertown, Cambridge, Newton, Arlington, Brookline, and Waltham, with four logged in the past two days. These are presence records reflecting where observers have reported the species, not a measure of population size or density.

This planthopper, native to China and Southeast Asia, arrived in Pennsylvania in 2014 and has spread steadily north. Its preferred host is (Ailanthus altissima), itself an invasive that has colonized disturbed ground throughout this area — a ready-made food source. Adult lanternflies feed on the phloem of a wide range of trees, including maples, oaks, black walnut, and wild grape, depleting carbohydrate reserves and excreting a sticky honeydew that coats leaves and encourages sooty mold. If you spot one, report it on iNaturalist.

Data from iNaturalist

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