When you buy a geranium in a nursery or in a hypermarket, it is almost obligatory to buy an insecticide against the geranium auger. And it is that this pest is spreading more and more in Europe (especially in the Mediterranean basin), wreaking real havoc on the ornamental geraniums, so common in our territory.
Current insecticides are extremely effective against the geranium caterpillar, although we also want to tell you about some low impact solutions for its control in this article, since we are going to have to make several applications throughout the flowering period and , inevitably, for many years. .
What are the symptoms of the geranium moth? Well, we have good news, because this pest is very easy to identify, and not precisely because of the caterpillar, well hidden inside the stems, but because of the visual symptoms that geraniums usually show.
If you are interested in how to identify and control the geranium caterpillar or borer (Cacireus marshalli), keep reading our article.
read more: tips for making geraniums bloom
How to identify the geranium borer
The geranium borer (Cacireus marshalli), also known as geranium moth, geranium caterpillar, or African moth, is an insect that usually invades these plants, usually during hot weather and when geraniums bloom.
If we see small moths hovering over our ornamental plants, it is likely that they are or have already spawned on the stems, which is the stage of the pest causing the real problem.
If we don’t detect anything, what we need to check periodically is the condition of the geraniums, especially during flowering and when temperatures rise.
We will carefully observe the flowers and analyze the stems, in case one is flaccid or we notice that it may be hollow. If we see a hole through which the eggs have been introduced, the quickest way to act is to apply the insecticide directly.
What if you haven’t found anything strange? Others Geranium Moth Symptoms they can be the following:
- Absence of flowering or fall of petals before opening.
- General condition of the weakened geranium.
- Black butterfly droppings can be seen on stems or leaves.
- Flower buds that never stop opening.
When faced with any such symptoms, it is best to quickly seek out an authorized insecticide at any nursery, specialty store, or even online store, and apply it according to the manufacturer’s recommendations.
At the same time, it is also advisable to prune the affected stems and add a fertilizer to the irrigation to promote the regeneration of the stems and increase the vigor of the plant.
read more: tips for making geraniums bloom
Geranium caterpillar life cycle (Cacyreus marshalli)
The African butterfly needs warm temperatures to flourish, so it will appear on your geraniums from a constant temperature of 20°C. In the Mediterranean space, there is a period of time that responds to these thermal requirements and that goes from May to early October.
This is when its life cycle begins with the laying of its eggs inside the stems of the geranium. To do this, he creates a gallery where he presents them until they hatch. Within days, a light green caterpillar will begin to deliberately engulf all of the flower stalks and subsequently the inside of the stem, leaving it hollow.
These caterpillars are green, although they darken over time. They are between 10 and 15 mm long, hiding from human view on the underside of leaves. This caterpillar will turn into a chrysalis and repeat the cycle as long as the temperature allows it.
Once the caterpillars have left a dry stalk, they open a hole to exit and go to another stalk-like victim. And so on until the plant is completely destroyed.
Affected stems can even split, although before that we will see how they slowly darken, lose all their sap and dry out.
Geranium Borer Treatments
The most important thing is, once you have identified it as the geranium moth, to find ways to combat and completely eliminate this pest.
Use of insecticides
The easiest way is to use insecticides. In specialty stores, nurseries or even online stores we will find an interesting range of different options.
In these, the most common active ingredients are cypermethrin (10% w/v cypermethrin) and a mixture of different components (ABAMECTIN 0.0015% + PYRETHRINS 0.02%).
Other active ingredients may be Deltamethrin 2.5%
However, one can also find solutions with less waste and less toxic to apply, but they will require more patience and number of applications.
In prevention, foliar applications are recommended every 15-20 days and curative treatments (plague detected) every 7 days.
Low impact insecticides african butterfly face
neem oil
When we want to look only for low impact nature insecticide options, neem oil is an effective alternative. It will only take patience to break the cycle, since the mode of action of azadirachtin (main component of neem oil) works by ingestion and contact only in the larvae.
Neem oil is applied by foliar spray on the whole plant, wetting all the surfaces abundantly but without draining them, in the first hours of the day or the last hours, before nightfall.
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- 【High Quality】Highest quality cold pressed virgin concentrated neem oil for agricultural use.
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- 【Agriculture】This neem oil is very effective in fighting and getting rid of enemies in the garden. You can get healthier fruits and vegetables.
- 【Potassium Soap Supplement】It is widely used together with potassium soap, which is used as an emulsifier to be mixed with water.
Dosage of neem oil (3% azadirachtin): 1 ml/litre of water (100 ml/hl), apply every 7-15 days.
Bacillus thuringiensis
This bacterium is widely used against all kinds of caterpillars, including geranium. Its form of action, applied foliarly, consists in affecting the digestive system of Lepidoptera, leading to short-term death.
Biological control
Since the geranium borer was recently introduced to Europe and, in particular, to the Mediterranean, it currently has no natural enemies capable of effectively controlling the populations of this caterpillar, so in most cases chemical control must be used to prevent serious damage to plants.
We could speak of biological control by the use of bacteria Bacillus thuringiensisdiscussed above.