Lily Leaf Beetle Description

• The lily leaf beetle is about a quarter-inch long with a scarlet body and black head and underside. These small insects, which squeak when they are gently squeezed, lay reddish-orange eggs in an irregular line on the underside of leaves. Larvae are reminiscent of slugs, are orange, brown, yellow or green with black heads and carry their excrement on their backs. Both adults and larvae feed on leaves, stems, buds and flowers, often consuming much of the plant if left unchecked.
  
  

Lily Leaf Beetle Control

• If the lily plants are not too numerous or widespread, handpicking the beetle and its eggs may provide effective control. Insecticides that contain maliathon and carbaryl will kill the beetle but are also toxic to beneficial, non-target insects. Instead, neem oil can be used effectively to kill larvae and repel adults.
  
  

Aphids

• A number of aphid species, including the lily aphid, can become major pests on a lily. These small, wingless or weak-flying pests use piercing mouthparts to feed on plant fluids. They can reduce plant vigor, spread viruses and excrete a sticky, sweet substance known as honeydew that hosts unsightly sooty mold. Identifying the exact species of aphid and understanding its habits and life cycle will generally make controlling it easier. Aphids can be addressed with occasional strong blasts of water that knock the pests off plants. Control weeds near the lilies that tend to host developing aphids. Insecticidal soaps will also control aphid numbers.
  
  

Thrips

• Thrips are small, delicate insects with fringed wings that feed on various plant parts. On Stargazer lilies, thrips are most likely to be found damaging buds and in open lily flowers. Thrips damage will generally appear as streaked or malformed flowers. Predatory insects often help to control thrips, so avoid the use of broad-spectrum insecticides. Remove and destroy heavily infested plant parts. Narrow-range horticultural oils may offer some control.
  
  

Additional Possible Pests

• A number of additional pests may occasional prove problematic. Deer, rabbits, grasshopers and slugs can quickly ruin Stargazer lilies in the landscape. Apply repellents to protect these plants. The root knot, foliar and stem and bulb nematodes are occasional pests on lilies raised in field production. Proper sanitation and crop rotation will alleviate nematode problems.