Bug FAQWaterlily Leaf Beetle
Galerucella nymphaeae · Order: Coleoptera · Family: Chrysomelidae
Also called: Leaf beetle, Water-lily Leaf Beetle, Water-lily beetle
Source: Wikipedia
The waterlily leaf beetle is a small (6 to 8 mm) oval beetle with yellow-brown sleek hair and mottled wing tops; its legs and antennae are darker. Adults and larvae feed on water lily foliage, causing rapid browning, rot, and smaller, less attractive replacement leaves, and they may also attack other water plants.
Source: Wikipedia
How to recognize it
Its legs and antennae are darker than the yellow-brown body.
Source: Wikipedia
Is it a pest in the house?
Feeding damage makes water lily leaves turn brown and rot, and new leaves are smaller and less decorative; other water plants can also be attacked.
Source: Wikipedia
Where it lives
Adults overwinter on shore and usually produce two generations per year in central Europe, with the first generation near the shore; warmer lakes can allow up to four generations.
Source: Wikipedia
What it eats
Both adults and larvae eat water lily leaves, quickly damaging the leaf surface.
Source: Wikipedia
Life cycle
A female lays 80 to 120 eggs in her lifetime; the larvae develop on the leaves, then form orange-yellow pupae that stick to leaf surfaces for about a week, shedding three times over 5 to 10 days before emerging as adults.
Source: Wikipedia
When you see it
In typical central European conditions there are two generations per year, but thermal lakes can increase this to four.
Source: Wikipedia
Where it comes from
It occurs in North America and Europe.
Source: Wikipedia
Where it is found in the US
Recorded in 42 of 51 states and DC. Most records: Alaska, South Carolina, Florida, Pennsylvania, Michigan, Maine, New York, Massachusetts.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada; native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
How do I control waterlily leaf beetles?
Remove the damaged leaves, lay them on a hard surface and heat them under black plastic in the sun, or apply a Bacillus thuringiensis-based biological insecticide where it is available.
Source: Wikipedia
What damage do waterlily leaf beetles cause?
Their feeding quickly browns and rots water lily leaves, and the replacement leaves are smaller and less attractive; they may also attack other water plants.
Source: Wikipedia
How many generations do they have each year?
In central Europe they usually have two generations per year, but in warm thermal lakes they can produce up to four generations.
Source: Wikipedia
Where is the waterlily leaf beetle found?
It is found in both North America and Europe.
Source: Wikipedia
Same family (Chrysomelidae)
Spotted Cucumber BeetleDiabrotica undecimpunctataDamages trees, gardens or crops
Bean WeevilAcanthoscelides obtectusDamages trees, gardens or crops
Cowpea WeevilCallosobruchus maculatusDamages trees, gardens or crops
Swamp Milkweed Leaf BeetleLabidomera clivicollisDamages trees, gardens or crops
Alder Leaf BeetleAgelastica alniDamages trees, gardens or crops
Dogbane Leaf BeetleChrysochus auratusSources
- Wikipedia: https://en.wikipedia.org/wiki/Galerucella_nymphaeae
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-24 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-24.