Lily Leaf Caterpillar

Written by kimberly sharpe Google
  • Share
  • Tweet
  • Share
  • Pin
  • Email
Lily Leaf Caterpillar
The lily leaf caterpillar can cause widespread destruction of water lilies. (Jupiterimages/liquidlibrary/Getty Images)

The China mark moth (Nymphula stagnata) resides near waterways that contain an abundance of aquatic plants, such as water lilies and duckweed. The mottled brown moth lives only a few days. It spends its short lifespan breeding. The female lays her eggs on the underside of aquatic plant foliage. The larvae of the moth, known as the lily leaf caterpillar, feeds voraciously on the aquatic plant life. The insects' excessive feeding can severely damage water lilies.

Appearance and Behavior

Upon hatching, the caterpillar burrows into an aquatic plant's soft leaf tissue. The caterpillar grows to a length of approximately 22mm. The lily leaf caterpillar constructs a silken nest from aquatic leaves that it sandwiches together using silk. The caterpillar hides within the canoe-shaped shelter when not feeding or when it must seek refuge from possible predators. The shelters often work as a transport system for the caterpillars as they float across the water to other aquatic plants.

Feeding and Breathing

The caterpillar consumes the soft inner surface of the leaf first. It seeks air through the natural air pockets that occur in the plant's leaf openings. After eating the plant's leaf, the caterpillar begins to feed on the leaf's stem. The caterpillar can consume the stem beneath the water's surface, but it must crawl to the surface often to seek air. The caterpillar breaths air using the tip of its tail, which it often sticks above the water's surface to take a quick breath.

Caterpillar to Adult

The lily leaf caterpillars spends all summer, fall and winter feeding on the aquatic plants. In the spring, the caterpillar pupates into an adult moth. The caterpillar will pupate within its silken nest that it uses as a refuge. It cements the cocoon to an aquatic plant above or below the water line. Within its silken cocoon, the caterpillar's outer body surface turns into a hard pupa. In approximately three weeks, the hard outer surface of the pupa cracks open to release the adult moth.


Consider handpicking the lily leaf caterpillars from the aquatic plants. Scoop the caterpillar's cocoons from the water and expeditiously dispose of them. Skim the water, using a pond or swimming pool net to pick up any floating cocoons. Look closely at floating, damaged leaves because they may contain cocoons. If the infestation of caterpillars is severe and widespread defoliation begins to appear, remove all of the top growth of the aquatic plants and destroy the debris to kill the caterpillars. Allow the plants to regrow new vegetation to help control the pests.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.