Spotted Lanternfly Arrives in New Hampshire: What Farmers Should Know

Spotted Lanternfly Arrives in New Hampshire: What Farmers Should Know

Spotted lanternfly (SLF) has been detected for the first time in New Hampshire, with a small number of adults confirmed in Rockingham County. While there is currently no evidence of an established population, growers should begin scouting now, particularly along field and vineyard edges, wooded areas, and near Tree-of-Heaven. Early detection, sanitation, equipment inspection, and other IPM practices will be important for limiting SLF establishment and spread. If you spot a suspected SLF, take a photo, record the location, and report it through NHBugs.

The New Hampshire Department of Agriculture, Markets, and Food (NHDAMF) has confirmed the first field detection of spotted lanternfly (Lycorma delicatula) in Rockingham County. A small number of adults were found and confirmed by USDA identifiers. At this time, there is no evidence of an established population, and additional surveys are underway to discover the extent of this detection.

If you see a suspected spotted lanternfly, take clear photographs and record the location. NHDAMF is asking residents and businesses to report suspected sightings. Early detection gives growers and agricultural agencies the best opportunity to respond before populations become widespread. Report through NHBugs here: nhbugs.org/reporting-form.

Spotted lanternfly (SLF) is an invasive planthopper first detected in Pennsylvania in 2014 and has since spread to many states in the Northeast and New England including NY, MA, CT and RI. SLF feeds on more than 100 plant species including Tree-of-Heaven, hardwoods, and ornamentals, but grapevines are particularly susceptible to heavy feeding. The insects pierce trunks, canes, and other plant tissues to feed on sap. For farmers, scouting, early detection and integrated pest management (IPM) will be key to keeping populations from becoming established. 

SLF adults. Credit: Richard Gardner, Bugwood.org

Heavy feeding can reduce photosynthesis and deplete carbohydrate reserves in roots and canes. In grapevines, this can lead to lower fruit sugar accumulation, delayed ripening, reduced yields the following season, and weakened vines. Late-season feeding may also reduce cold hardiness and increase the risk of winter injury and bud mortality. Research is ongoing to establish action thresholds. 

Adult SLF feeding on Vitis. Credit: Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org

SLF also produces honeydew, a sticky substance that encourages sooty mold growth and can coat leaves, further reducing photosynthesis. It is also attractive to ants, wasps, and bees. 

From what we have learned from other states, SLF has one generation per year:

• Egg masses: Found from fall through spring on tree trunks, posts, equipment, vehicles, rocks, and other smooth surfaces. They often look like gray or brown patches of dried mud.

Multiple SLF egg masses under tree bark. Credit: Emelie Swackhamer, Penn State University, Bugwood.org

• Nymphs: Appear in late spring. Young nymphs are black with white spots and older nymphs are bright red and black with white spots. Nymphs are very mobile and can jump.

Left: SLF nymphs feeding on blueberry. Credit: Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org
Right: 4^th instar SLF nymph. Credit: Richard Gardner, Bugwood.org

• Adults: Appear in late summer and can remain active until the first hard frost. They have distinct spotted wings and are the most damaging life stage for grapes.

Left: Adult SLF, wings spread. Credit: Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org
Right: SLF adult. Credit: Emelie Swackhamer, Penn State University, Bugwood.org

Year-round monitoring is an important part of managing spotted lanternfly. Regular scouting helps growers identify infestations early, determine which life stage is present, and time management practices appropriately. Scout vineyard edges, field borders, nearby wooded areas, and locations with Tree-of-Heaven (TOH). Tree-of-Heaven is an invasive tree and a preferred host of SLF. TOH can provide an important feeding and breeding site where SLF populations build up. In addition to nymph and adult locations, scout surfaces of potential egg-laying sites too. 

Tree of Heaven. Credit: Richard Gardner, Bugwood.org

Cultural practices can include identifying and managing TOH near vineyards and reducing potential egg-laying sites such as unnecessary posts, debris, and other smooth surfaces. Managing TOH can be an important part of reducing suitable habitat, but control should be approached carefully because simply cutting the tree can result in vigorous regrowth.

SLF egg masses on wood. Credit: Emelie Swackhamer, Penn State University, Bugwood.org

Mechanical controls include inspecting and cleaning equipment before it is moved, removing egg masses during the dormant season, and manually removing insects or using appropriate traps (like sticky cards or circle traps) when practical. Spotted lanternfly can spread on vehicles, trailers, equipment, firewood, pallets, and other materials. Inspect and clean equipment before moving it, especially if it has been in an area where SLF is present. In addition, if you had high SLF pressure in the summer or fall, bud evaluation is warranted before pruning. You may need to increase the number of buds to compensate for bud mortality.

New SLF egg clusters and SLF adult on garden tool. Credit: Kenneth R. Law, USDA APHIS-PPQ, Bugwood.org

Generalist predators will feed on SLF but will not keep populations below damaging levels. There is ongoing research into a parasitoid species that attacks SLF in its native range and may be a possible biological control agent in the future. 

Chemical control should be considered as part of an overall IPM program when pest pressure warrants it. Because pesticide labels and approvals vary by state and can change, New Hampshire growers should always verify current product registrations and labels before making an application. SLF is a recently introduced pest, and therefore it is not included on many chemical labels. However, many insecticides targeted at other vineyard pests may effectively control SLF. In addition, due to the timing of adult SLF feeding on grapes, pre-harvest intervals could make chemical management challenging close to harvest. 

A strong scouting plan will be the primary management option for organic and low input vineyards, though there are some OMRI-approved products that may provide moderate control like insecticidal soap or entomopathogenic fungi. 

Currently, the most effective overall strategy is a combination of regular scouting, sanitation, habitat management, and appropriately timed control measures when warranted.

Extension resources for more information, especially related to SLF and grapes:

• Biddinger, D., F. Acevedo, M. Centinari, G. Krawczyk, and C. Hickey. April 2025. Penn State Extension. Spotted Lanternfly Management in Vineyards. (includes host table, information on insect exclusion netting, and detailed insecticide information for PA). extension.psu.edu/spotted-lanternfly-management-in-vineyards
• Dube, M., P. Siegert, and J. Ebba. March 2023. Spotted Lanternfly: Update and Best Practices. UNH Extension Webinar featuring speakers from NH Department of Agriculture, Markets and Food. media.unh.edu/media/Spotted+Lanternfly%3A+Update+and+Best+Practices/1_2ehvmmvc
• Galvan, J. November 2025. UMass Extension fact sheet. Grape IPM – Spotted Lanternfly. umass.edu/agriculture-food-environment/fruit/fact-sheets/grape-ipm-spotted-lanternfly-lycorma-delicatula
• Krantz, A., M. Tebo Davis, and E. Belair. May 2019. UNH Extension. Double Trouble Double Invasion. extension.unh.edu/blog/2019/05/double-trouble-double-invasion