The control refers to the removal of the existing spider nests in the Krefeld city area. Since the oak processionary moth nests are danger spots from the 3rd larval stage, the nests must be removed and disposed of within 48 hours of notification (affected locations will be sent by e-mail) on the instructions of the client. When removing the nests, it must be ensured that the spider nests are compactly removed as a whole and that the caterpillar hairs are not released in the process. Alternatively, the nests can also be vacuumed with an H-class safety vacuum cleaner with the additional "asbestos" test in accordance with TRGS 519. The extracted material is to be sent to waste incineration in sealed bags. The variant of burning the nest is not desired!

In the Krefeld city area, about 2,250 oaks grow on streets, paths and squares. Since the oak stands are between 5.0 and 30 meters high, the control is divided into three categories. Category I includes tree sizes < 10.0 metres in height, oaks between 10 and 20 metres in height fall into category II and oak trees between 20 and 30 metres in height are covered by category III. It can be assumed that a maximum of 15 nests (per tree) are to be removed. If there are more than 15 nests to be removed from the tree, there is the possibility of percentage surcharges (per tree) after prior consultation with the construction management.