Lilac miner moth, leaf miner or lilac moth (Gracillaria syringella)
In the Leaf miner it is an inconspicuous, small butterfly whose pupae overwinter directly on the lilac. In May, the larvae hatch and feed primarily on the leaves. They are also found less often in the soft shoot axes. Leaf miners are not only very common on lilacs, although the first generation usually leaves little damage.
- Symptoms: olive brown spots on leaves, dying and brown discolouring leaf areas, destroyed leaf tissue, yellowish larvae in the leaf
- Control: normally not necessary, spray when budding
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Lilac weevil, black weevil (Otiorhynchus rotundatus)
This is a red-brown beetle up to six millimeters long that only eats at night and stays on the ground under leaves and other hiding places during the day. Its larvae also live in the soil and can severely damage the roots due to their hunger. An infestation can only be determined by using tricks: place a clay pot filled with wood wool under the lilac, the vine weevils will use this as a hiding place and you can use it collect.
- Symptoms: eroded leaf edges
- Control: collection, treatment with neem possible in the event of severe infestation, use of nematodes such as roundworms of the genus Heterorhabditis
Hornets (Vespa crabro)
Hornets mainly use wood or wood to build their nests. Bark that they peel off the trees themselves - for example on lilacs.
- Symptoms: peeling resp. Feeding points on the shoots, very rarely withering leaves and dying branches
- Control: only useful in the case of a large-scale infestation. Hornets are protected and should therefore be left alone
Gall mites (Eriophyes loewi)
These are tiny mites, only about 0.2 to 0.5 millimeters in size, which belong to the group of arachnids and feed on plant sap.
- Symptoms: light green discolored leaves, thickened buds, short shoots, formation of "witch's brooms"
- Control: remove infected leaves, spray with rapeseed oil preparation (neem) in early spring, loosen the root disc, plant wild garlic
Tips
If no pests can be found on the lilac in spite of obvious damage, in many cases there is one Fungal infection behind.
