A keen gardener looking for organic, pet-friendly ways to deal with garden pests.
Lily flowers add a great splash of colour to your summer garden. They can have pink, red, orange, yellow or white flowers and many varieties have a lovely fragrance. Lily plants have magnificent, trumpet-shaped flowers borne on long upright stems covered in narrow leaves. Equally happy in a container or a garden border, lilies are simple to grow from bulbs and return to flower again year after year.
The Lily Beetle
The red lily beetle is a destructive pest that can ruin your lily plants. Both the adult beetle and its larvae eat the foliage of a lily and can destroy a plant in a matter of days. There are insecticide sprays that are effective against both lily beetles and their larvae, but these sprays can often also be harmful to bees and other insects. Insecticides may also be harmful to your pet—Florrie Labradoodle quite frequently has her head buried amongst my lily plants to retrieve a ball or toy!
The adult lily beetles overwinter in the soil and emerge in springtime to lay their eggs on the underside of lily plant leaves. The eggs take just a couple of weeks to hatch. The grubs eat for around a month before moving back into the soil to pupate. After another month, they emerge as beetles and continue to eat your lily plants before returning to the soil to overwinter.
How to Identify a Lily Beetle
The adult lily beetle is around 7 mm in length. It has bright red wing cases with a black head, legs and undersides. Their larvae are a similar length to the adult beetle and have a slug-like appearance. Disgustingly, they are usually hidden beneath a pile of their own black slimy poo! This is to disguise themselves and deter predators. They can often be mistaken for bird droppings!
Lily beetles can also make a “squeaking” noise when under attack to surprise and deter predators. Lily beetle eggs are an orangey-red colour and tubular shaped—almost like a row of small sausages on the underside of leaves!
Here are some organic options to try to rid your garden of the lily beetle and keep your pet and friendly insects safe!
Stopping Lily Beetles by Hand Picking
The first method to try to rid your garden of lily beetles is to pick them off! Daily patrols are essential! The lily beetles’ bright scarlet colour acts as a warning to birds and other predators, but also makes them easy to spot by a keen gardener!
You will need to be quick to grasp them as the beetles’ drop to the ground at the slightest hint of trouble. They fall and lie on their backs and become almost impossible to spot on the soil. I put some newspaper around the base of my lily plants so they can’t escape. Squash them firmly under your shoe before they fly off! Do the same with any grubs or eggs you see.
If you don’t want to handle the larvae or eggs, then just take the whole leaf off and crush it under your foot!
To create a homemade spray, mix together a potion made of a couple of teaspoons of olive oil or vegetable oil with 1 teaspoon of washing-up liquid and 500 ml of water. You can use hand wash soap instead of washing up liquid if you prefer. Place into a spray bottle and give your lily beetles and their grubs a regular “spritz”!
Neem oil is an option recommended by organic gardeners for control of lily beetles. It is pressed from the seeds of the neem tree—a tree native to India and South Asia. When diluted appropriately, it is safe to use as a plant spray and won’t harm cats, dogs and friendly insects. Neem oil is harmful to pests that eat the sprayed foliage—such as lily beetles! Be aware that neem oil has an unpleasant smell like garlic and sulphur combined!
Dilute the neem oil according to the manufacturers’ instructions—this is important as off-the-shelf products can be of different strength. I recommend you test on a small area of a plant before you spray everywhere, as too strong a solution may burn your plant leaves.
Enjoy your lilies this summer!
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.