Oleanders impress with their joy of growth, sprawling, generous growth forms and lush flowers. In addition to the people, other "guests" also enjoy this splendor again and again. Above all, small, yellow lice prefer the oleander as a host plant and - once they have arrived - quickly attack it in droves. Various remedies promise a remedy, from established home remedies to “chemical mace”.
What are yellow lice?
Since yellow lice are mainly observed on oleander plants, these pests seem to be something very special. Or not?
No. In fact, the colorful parasites are "normal" aphids. However, like the oleander itself, this subspecies is native to more southern regions around the Mediterranean. Due to a certain host specification of the animals, they can mainly be found where they feed in their natural habitat. For you as a plant lover, this is expressed in an infestation that is almost exclusively limited to oleander plants.
Why fight aphids?
Like all relatives, the yellow aphids feed on the sap of the host plant. The bites in the plant tissue damage the leaves and stems and they die off with increasing intensity. In addition to this long-term cause of death for the oleander plants, the honeydew secreted by the lice is a much greater danger. The sugary solution is an ideal breeding ground for fungi and bacteria and can therefore quickly become a focus of infection. Fight the aphids, also eliminate the basis of numerous serious diseases of your plants.
Measures against yellow lice
No matter which measure you want to use to get rid of the annoying parasites, the effectiveness increases the sooner it is used. No action is 100 percent successful. The fewer animals there are, the higher the probability of catching them all.
The water jet
Commonly seldom recognized as a pesticide, a concentrated jet of water can quickly rid plants of yellow lice. As an additional benefit of this measure, the critical honeydew is eliminated and the risk of bacterial and fungal infestation is reduced to the normal level.
benefits
- No residue on plants or soil
- No harmful effects on beneficial insects such as bees, bumblebees etc.
- Can be repeated any number of times
- Can also be used at any time in sensitive areas such as terraces or balconies
disadvantage
- Risk of damage to flowers and leaves
- High effort with multiple repetitions
- Moderate success with little work diligence, since not all animals are recorded
TIP: For this method to be effective, you should ensure that the rinsed off lice do not end up on the same plant one floor down. Therefore, cover the soil with a tarpaulin or lay the oleander on its side while you spray.
collect
Especially in the initial phase of an infestation with just a few lice, collecting them, which at first seems strange, can actually be effective. Gardening gloves or a damp cloth, with which the animals can be wiped and crushed at the same time, are helpful.
benefits
- No damage to plants, soil or beneficial insects
- No chemicals on the plant
- Direct control of success visible during work
disadvantage
- Low efficiency, therefore only possible when infestation begins
- Skin irritations due to oleandrin (component of plant sap) possible
- Relatively high risk of overlooking individual animals
- Low effectiveness against honeydew
soap solution
As a first quick and, above all, one-time measure, soapy water can be helpful against an acute infestation of lice. The respiratory organs of the animals are disturbed and the stay is spoiled. On the other hand, it is much more important that the yellow lice can be easily removed from the oleander with a jet of water after the soap solution treatment, as they lose their grip on the plant.
curd soap
benefits
- Can be implemented quickly
- Very effective in combination with water jet
- Easy to make with household soap, soft soap or dish soap
disadvantage
- Basic properties unfavorable for plant and soil
- Therefore: regular use is not recommended
- Effectiveness as a sole measure only moderate
TIP: Cover the soil in the plant pot with foil before spraying with soap solution. In this way, the adverse effects of the lye are limited to the plant itself, while the soil and roots are spared.
rapeseed oil
An emulsion of about 1/4 canola oil to 3/4 water can be sprayed on the lice infestation as a quick and easy remedy. The respiratory organs of the yellow lice are blocked by the oil film and the animals suffocate.
benefits
- Not critical for plants and soil
- Easy to make at home
- No impact on bees and other beneficial insects that fly off when spraying starts
disadvantage
- Comparatively expensive due to the use of rapeseed oil
- Can be used repeatedly
- Optically unattractive oil film on plant
NOTICE: Similar to the rapeseed oil emulsion, milk can also be used. The fat it contains also has an effect here and is intended to kill the animals. However, if available, rapeseed oil is preferable, since milk has a strong odor impact when it coagulates.
nettle brew
A sprayable decoction can be created from all the components of the stinging nettle by soaking them in water for at least 24 to 48 hours. Diluted with 4 parts water to 1 part decoction, the oleander plants can be completely sprayed. The fragrances contained ensure that the lice seek distance.
benefits
- Crafted from weeds found almost everywhere
- Cost neutral
- Completely organic
disadvantage
- Must be repeated several times
- Danger of burning the leaves in strong sunlight
nettle manure
If the stinging nettle brew described above is allowed to ferment, the so-called liquid manure is produced. It can be used in the same way and also ensures that yellow lice on the oleander effectively disappear.
benefits
- Only to be used diluted 1 to 10, so it has a long range
- Good use of weeds
- Cost neutral
disadvantage
- Even higher risk of burning the leaves
- Strong odor nuisance
- Lengthy process
baking powder
As a last home remedy, baking soda, or even pure baking soda, can be used if you want to get rid of aphids.
In the reaction with water, the substance develops CO2, which causes the animals to suffocate. For use, a solution of one tablespoon of baking soda should be prepared in one liter of water, which can then be easily sprayed or poured.
benefits
- Inexpensive
- Odorless
- No harmful effects on plants or beneficial insects
disadvantage
- Permanent change in the soil pH value
- Unsightly white spots caused by baking soda deposits on stems and leaves