Spider moths in Berlin: White spider web covers our trees!

Spider moths in Berlin: White spider web covers our trees!

In Berlin, numerous trees are affected by a remarkable infestation of web moth caterpillars. These caterpillars, which belong to the web and bud moth family, have no hair at all, but protect themselves by spinning in threads. This year the webs are particularly large and impressive, so that entire trees are surrounded by the threads. The drought of the past four months has contributed significantly to this spread.

The caterpillars eat the fresh shoots of the trees, which can lead to leaf damage. However, this does not usually harm the trees and, provided they are healthy, they can sprout again after an infestation. Affected tree species such as Pfaffenhütchen, bird cherries and rock medlar can often be observed. The caterpillars themselves pose no threat to humans, while at the same time they are an important source of food for birds.

Caterpillar behavior and control

A caterpillar can spin up to ten meters of thread per day. The moths usually pupate between June and July and develop into moths within about two weeks. If there is an infestation in your own garden, it is advisable to either cut out the webs or hose them off with a hard jet of water. The use of pesticides, however, proves to be of little use because they are not effective.

To prevent an infestation, it is helpful to remove the web moth eggs in autumn and attach glue rings to trees and bushes. Pheromone traps in late summer can also help reduce web moth proliferation. If the infestation is severe, especially on fruit trees, control may be necessary to avoid crop losses. Dense nest structures can be cut out or removed with a water jet; however, disposal should be done outside the garden to prevent re-infestation.

Affected plants

In addition to the tree species already mentioned, poplars, hawthorn, blackthorn, willows and hawthorns are also threatened by the web moth. Even fruit trees such as apples, plums and plums show signs of infestation. The caterpillars spend the winter underneath and appear on the leaves in spring, making the need for timely and preventative control essential.

Overall, spider moth infestations provide a fascinating, if worrying, perspective on the interaction between flora and fauna in urban spaces. It remains to be seen how weather conditions will affect the development of the moth population in the coming weeks, but heavy rain could be particularly devastating for the moths.

For detailed information on how to keep the web moth at bay, we refer to the reporting by South Germans and further insights from My garden expert.