HOW CAN YOU GET RID OF THE RED LILY BEETLE?
So how do you kill the scarlet lily beetle? This is quite possibly the best question I have asked this summer. Why, because my prized Nepalese lilies are covered in them and I have already spent over an hour this morning popping and squishing both the red adults and their evil looking larval children. My first recommendation is to wear gloves when commencing this course of action but unfortunately I saw red (how appropriate) as I cast my eyes over the ravaged mess that was once luxuriant foliage.
In a further attempt to avoid discovery, the dull orange larvae will first hatch, then cover themselves with excreta to deter predators allowing themselves to feast on both the lily leaves and flowers with impunity!
Once they have had their fill they will drop to the floor and bury themselves in the soil beneath your plants in order to pupate before hatching out in their scarlet adult form. In this manner they are more than capable of producing multiple generations in a single year. This is why it is important to regularly check your lily plants late in the season, even when there are no longer any flowers. You really cannot take your eye of the ball with regards to this.
Because of the juveniles effective camouflage and the adults capacity to hid and drop out of site, squashing lily beetles as a control method may not be particularly practical, although it can me extremely satisfying. As a far more effective measures go - and particularly with heavy infestations - you may need to apply a systemic insecticidal spray.
Alternatively, use a contact insecticide such as Permethrin, one of the Pyrethroid insecticides. Just be aware that you will need to apply Permethrin on a regular basis and it will only kill what it touches. As mentioned before, do not spray the flowers as again, it will kill beneficial pollinating insects.