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LanternflyWatch

Visual Field Guide · All Life Stages

Know Your Enemy:
SLF Biology Field Guide

Spotted lanternfly looks completely different at each life stage — most people only recognize adults. This guide covers every stage you might encounter, from the egg masses in winter to the sooty mold left behind in fall.

Report a SightingInteractive ID Checklist

Life Cycle Overview

Eggs
1st–3rd
4th (Red)
Adult
Carcass
Honeydew

Sept–Nov: eggs laid · Apr–Jun: early nymphs · Jul–Aug: red nymphs · Aug–Nov: adults · Oct–Nov: die-off · Aug–Oct: honeydew/mold

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Eggs

Egg Masses

size ~1" × 0.5"season Sept–May

Fresh egg masses look like a smear of gray-brown putty or dried mud. Weathered masses crack and turn dark brown/gray with a scaly, almost bark-like texture — easy to overlook on rough surfaces.

ID Tip

Looks exactly like dried mud. Most people walk right past them. Run your fingernail along any gray-brown smear on hard outdoor surfaces — a mass has a subtle ridged structure underneath.

  • Each mass contains 30–50 eggs arranged in rows of 7–10
  • Laid on any hard surface: bark, rocks, patio furniture, vehicles, fences, house siding
  • Tree of Heaven trunks are priority search surfaces
  • Eggs hatch April–May — scrape before spring
  • Kill method: scrape into a bag with isopropyl alcohol or hand sanitizer
Egg scraping guide →
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Early Nymph

1st–3rd Instar Nymphs

size 1/8"–1/4"season April–June

Tiny, jet black with bright white polka dots. The white dots are perfectly circular and evenly spaced — a pattern unlike any native North American insect at this size. Very fast-moving; they jump when disturbed, making them hard to catch.

ID Tip

The perfectly circular, evenly spaced white dots are diagnostic. Native look-alikes at this size are brown/gray with irregular spotting, not stark white-on-black.

  • Climb host plants immediately after hatching
  • Feed on tender new growth — sap from stems and leaves
  • Found on Tree of Heaven, grapevines, hops, willow, black walnut
  • Jump several inches when approached — capture requires a cup or bag
  • Band traps on host trees are effective at this stage
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Red Nymph

4th Instar Nymph (Red Stage)

size 1/2"–3/4"season July–August

The most visually striking stage — and the one most commonly photographed and shared on social media. Dramatic red-and-black coloring with bright white dots. If you've ever seen a photo that made you do a double-take, this is probably what it was.

ID Tip

The red color at this size is unique. No native insect in the eastern US looks like this. If you see something red-and-black with white dots in July or August, it's an SLF nymph.

  • Begin aggregating in large groups on preferred host stems
  • Highly mobile — will flee to the underside of leaves when approached
  • Still vulnerable to direct squishing, soapy water spray, or neem oil
  • Transitioning to adult feeding behavior — heavier sap extraction begins
  • Tree of Heaven and grapevines are prime congregation spots
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Adult

Adult

size 1"–1.25"season Aug–Nov

At rest: looks like a gray-brown moth with black spots on tan/beige forewings — easy to dismiss as a common moth. Wings open reveals a startlingly vivid surprise: bright scarlet-red hindwings with black spots and a white band at the edge.

ID Tip

The "open wing reveal" is unmistakable. At rest, nothing distinctive. But the moment they open their wings, that red is unlike anything native to North America. Also watch for large aggregations on tree trunks at dusk.

  • Aggregate on host plant trunks in large groups — especially at dusk
  • Excrete "honeydew" (sticky, sugary waste) that drips onto surfaces below
  • Peak season: late August through September
  • Females lay 1–2 egg masses before dying in late fall frosts
  • Die from frost October–November — but egg masses persist all winter
Control methods guide →
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Carcass

Dead / Carcass

size ~1"season Oct–Nov

Adults die from frost. Carcasses collect on sidewalks, porches, window sills, and anywhere they were feeding. Still identifiable from the gray wings with black spots — and the red hindwing may still be partially visible in recently deceased specimens.

ID Tip

A carcass still confirms presence. Finding a dead SLF in a new area is worth reporting — it tells researchers exactly how far the population has spread, even if adults are no longer active.

  • Gray tan forewings with black spots remain visible post-mortem
  • Confirm ID before reporting — common moths can look similar
  • Finding dead ones in October–November is normal at the end of season
  • Egg masses laid by these adults are still on surfaces nearby
  • Prioritize egg search in any area where carcasses are found
Report a sighting →
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Secondary Damage

Honeydew & Sooty Mold

size Variableseason Aug–Oct

SLF excretes large amounts of sugary honeydew as it feeds. This sticky, shiny substance coats leaves and surfaces below the feeding site. Within days, black sooty mold colonizes the honeydew — leaving a distinctive black crusty coating that is often the first sign people notice.

ID Tip

If you see a black crusty coating on leaves, stems, or outdoor furniture below a tree — look up. SLF is almost certainly feeding in the canopy above. Also watch for unusual wasp and yellow jacket activity around trees in late summer.

  • Sooty mold doesn't directly kill plants but blocks photosynthesis
  • Repeated heavy infestations weaken plants over multiple seasons
  • The black coating on hard surfaces (decks, cars) is difficult to clean
  • Attracts wasps, yellow jackets, and hornets to the sugar source
  • Grapes and hops experience yield loss from honeydew coating
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See Real Photos From Your Neighbors

iNaturalist has hundreds of thousands of confirmed SLF photos — eggs, nymphs, adults, and honeydew damage — submitted by citizen scientists across the eastern US. Browse observations near you to see exactly what each stage looks like in the field.

Browse iNaturalist observations →
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Report What You See

If you spotted one — any stage, alive or dead — add it to the map. Takes 90 seconds. Your report helps researchers track the spread in real time and helps your neighbors know what to look for.

Report a sighting

Related Guides

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Egg Mass Prevention

Step-by-step scraping guide for Sep–Nov.

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Tree of Heaven ID

Identify and remove SLF's preferred host.

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Control Methods

Every method ranked by effectiveness.

Weekly Fight Briefing

Stage-by-stage alerts when the season shifts. Free. Personalized to your zip code.

No spam. One briefing/week during season. Unsubscribe anytime.