If the citrus tree has been attacked by pests, you should try natural remedies and manual methods first. If these measures are ineffective, it makes sense to use biological sprays.
Lice should be fought in good time, because a heavy infestation is difficult to get under control
vine weevil
These dark brown, flightless beetles are about 1.5 centimeters in size and are nocturnal and leave indented feeding damage on the leaf edges. The larvae living in the substrate are crescent-shaped and yellowish-white in colour. They damage the roots of lemon trees.
Identify and control infestation
Put a cloth under the lemon tree and check it every morning. If disturbed, the bugs drop so that you can easily collect them. If you repot the sapling every two to three years, check the root ball for larvae. Nematodes, which are administered via the irrigation water, prove to be an effective antidote.
spider mites
The arachnids, which are about one millimeter in size, colonize the underside of the leaf and suck the plant sap out of the cells. Due to the inflow of air, these appear silvery. The areas later turn gray. The fine webs between the shoot tips and the leaves are clearly recognizable. If left unchecked, the foliage will dry up and eventually fall off.
prevent and combat
Spray the plant regularly with low-lime water to increase the humidity and make the living conditions for the mites worse. Spray off the insect pests with a hard jet of water. In order to effectively combat spider mites on the lemon tree, you should use biological means.
scale insects
This superfamily includes various pests that spread on the lemon leaves in unfavorable growing conditions. If the climate is not right, the composition of the plant sap changes and offers lice an attractive food source. They are a symptom and can be prevented if you adapt the framework to the needs.
Possible causes of an infestation:
- Hibernation in warm and dark rooms
- heavily shaded outdoor location
- insufficient ventilation in the crown
- Humidity is in a low range
- Plants are weakened by over-fertilization
Mealybugs and mealybugs
The females, which are about three millimeters in size, protect themselves with a floury layer of wax, under which they lay their eggs. They can move freely and colonize the undersides and axils of leaves, where they suck out the plant sap. If the pest spread is low, it helps if you brush off the insects. Dissolve 15 milliliters of spirit and curd soap in one liter of water and spray the agent into the inaccessible areas.
miner fly
The larvae eat through the leaf tissue, creating typical feeding tunnels. The silver-white to yellowish tunnels are visible against the light. Fecal crumbs appear as dark dots. A severe infestation weakens the lemon tree, so you should remove infested leaves in good time. If fly larvae appear on isolated leaves, you can crush them with your thumb and forefinger.