The tree tells you before the insect does. A trunk under heavy feeding weeps sap from the wounds, and the smell coming off that bark is wet and fermented. Spotted lanternflies drink sap, and that is the whole answer. You will not find chewed leaves and you will not find eaten fruit, so spotted lanternfly host plants take damage in the wood and foliage while the fruit above goes unpierced.
The mouthpart explains the rest. Think of a needle. The insect pushes that needle through the outer tissue, taps the vascular tissue underneath, and drinks, which is why you never see a chewed edge on a leaf. Feeding happens on stems, leaves and bark. On a grapevine that means the berries stay whole while the canes carry the insects, and a bad infestation can sit on your vine without a single pierced grape.
Tree of heaven is the host to check first. Adults in China prefer that tree over anything else growing nearby. That same tree carries cytotoxic alkaloids, which may leave the insects unpalatable to predators. Pennsylvania Department of Agriculture records a strong pull toward grapevines, maples, black walnut, birch and willow as well. Those five deserve a close look on your own land.
Tree Of Heaven
- Preference: In China, adults choose this tree over anything else growing nearby.
- Chemistry: Cytotoxic alkaloids in the tree may make feeding insects unpalatable to predators.
- First check: If one stands on or near your property, look here before you look anywhere else.
Grapevines
- Preference: Grapes sit among the strongest preferences on record, right alongside tree of heaven.
- Feeding site: Canes and woody stems carry the insects, and the berries are never pierced.
- What you see: You can find a vine packed with adults while the fruit still hangs clean.
Maples
- Species: Red maple and silver maple both appear on the confirmed United States host list.
- Preference: Maples rank as a strongly preferred host, not a fallback the insects settle for.
- Signs: Watch your trunks for weeping sap and that wet, fermented odor.
Black Walnut, Birch And Willow
- Status: All three count as strongly preferred hosts, and black walnut also sits on the confirmed host list.
- Where to look: Trunks and woody stems hold the older nymphs and the adults.
- Yard risk: These are common shade and street trees, so your property may already hold a favored host.
The full spotted lanternfly diet runs wider than any short list suggests, and the published counts do not agree with each other. Know that before you trust a single number from a single page.
The counts differ because the surveys ran at different times and covered different ground. Read the smallest number as a floor, not as a limit. A plant missing from one list may simply have gone uncounted, so do not read any single list as complete.
Age changes the menu too. Early nymphs work a wider host range and spread across more kinds of plants. By the fourth instar the nymphs move onto woody tissue and narrow down. That is why one walk turns up insects on soft green growth and a later walk finds the same insects clinging to trunks.
The list of spotted lanternfly host plants runs long, but your search order is short. Find the tree of heaven on or near your land and check that tree first, then work outward to the closest grapes and maples. Look for weeping sap and the fermented smell before you look for the bugs, because the tree gives the sign away sooner. Match your search to the stage as well, since older nymphs and adults sit on woody stems and trunks rather than on tender new growth.
Read the full article: Spotted Lanternfly: What It Actually Damages
