A native of Europe and Asia, this pest is now causing a problem for gardeners all over the world. Also known as Lilioceris lilii, most of the damages are evident when it is in its larval stage. When it comes to its physical characteristics, the adult lily leaf beetles have an average length of ¼ to ½ inch. They have a bright red body, black head, and antennae. The eggs, on the other hand, have an irregular shape. They are tan at first, but when they are about to hatch, they turn to orange then to deep red. Lastly, the larvae, which is the most destructive stage, looks like a slug. It is soft and plump. It has a back head and the color of the body can be brown, yellow, orange, or green.
Lily Leaf Beetle’s Habitat
Similar to other pests, its habitat will depend on its stage of development. The adults overwinter in leaf litter or the soil providing them with refuge from the cold temperature. On the first days of spring, they will start being active and start feeding, although they are no longer as damaging compared to their younger stages. When they are eggs, on the other hand, you can find them on the undersides of the leaf, usually in a cluster of up to 12 eggs. The larvae, meanwhile, will feed not only on the leaves, but also stems, flowers, and buds.
Identifying Lily Leaf Beetle’s Damage
The infestation of lily leaf beetle is evident on plants belonging to the group of true lilies and fritillaria. To be specific, some of its most common hosts include trumpet lilies, oriental lilies, tiger lilies, and Turk’s cap lilies. However, it is important to note that the adults can also feed on the leaves of plants that do not belong to the family of lilies, such as flowering tobacco, potato, and Solomon’s seal.
Here are some of the signs that will be indicative of the presence of lily leaf beetles:
- There will be spots on the underside of the leaves, which are the eggs of the lily leaf beetles. There will also be holes and the edges will appear as if they have been chewed. Eventually, it will show discoloration and will dry, which is because of the lack of nutrients. It can also fall off the vein, causing defoliation to the host plant.
- The petals, pods, and stems of the host plant will also show signs of infestation. They will have brown spots or dry patches.
Results of Infestation
Because lily leaf beetles have the reputation of being voracious feeders, expect that the damages will be evident within a short span of time. In most cases, it is already too late before you realize that they are indeed present. It will cause severe defoliation in the host plants. This deprives the plants of the nutrients that will be necessary for their survival. In the worst situations, this will cause the plant to suffer from abnormal growth and death.
How to Get Rid of Lily Leaf Beetles
Natural and Organic Solutions
The following are some of the best ways to eliminate lily leaf beetles in a manner that is safe and organic:
- Hand-picking is one of the methods that will work, although it is quite time-consuming. Because it is exhausting, this is best only for small-scale infestation. The larvae have excrements that cover their body, which are thicker as they eat more. This makes them squishy and hard to kill. A good alternative to manual crushing is to throw them in a bucket of soapy water. When removing them from the host plant, it is best to use gloves as they can sometimes feel gross because of the excrements in their body.
- Biological control also holds a lot of promise in regulating the population of lily leaf beetles. There are beneficial insects that will feed on them. Some of the best to have include parasitic wasps. They are available commercially. Also, you can grow flowering plants in the garden to encourage the presence of natural enemies that will kill lily leaf beetles.
- If you have to use insecticides, you have to be careful. Check their ingredients. Rather than using those that contain toxic chemicals, botanical pesticides are better options. With this, one of the best alternatives is neem oil. It will kill the lily leaf beetles without affecting beneficial insects. For the best outcomes, it is best to spray it early in the season. This will help to kill the larvae and prevent the adults from getting close to the plant.
When the infestation is severe and when the solutions mentioned above are not enough, chemical methods are promising. Nonetheless, this is one thing that needs caution. These chemicals are toxic even to beneficial insects and pets. It is also important to read the instructions from the manufacturer to use it the right way. Among others, some of the most common active ingredients are deltamethrin and lambda-cyhalothrin. Some of the most popular brands are Westland Resolva Bug Killer, Bug Clear Ultra, and Bayer Sprayday.
How to Prevent Lily Leaf Beetles
The most effective preventive measure is to take care of your plants. Make sure to pay attention to their healthy growth. Keep the surroundings free from decaying vegetation or litter that will provide a breeding ground for the lily leaf beetles.
To add, it will also help if you will focus on planting varieties that do not attract lily leaf beetles, such as daylilies. Other resistant lily varieties include Madam Butterfly, uchida, and black beauty.
Lastly, and perhaps most importantly, immediate action is necessary. You need to curb their presence before they can reproduce in high quantity. Acting early will let you get rid of the pest before they can wreak havoc.