"We discovered the first marmorated stink bugs near the Bärenwiese in mid-August 2019," reports Günter Plonka, district orchard advisor for the Ludwigsburg district. The thumbnail-sized bugs could be found on fruit-bearing ornamental shrubs such as cherry laurel and rose hips. With the end of the late summer temperatures and the change to autumnal weather, the bugs are currently increasingly seeking out sheltered homes and buildings to overwinter in. Although the animals are harmless, they are still a nuisance, especially when they nest in inaccessible cracks and hiding places. The tree bugs probably found their way to Ludwigsburg one or two years ago. However, the few individual animals have so far gone unnoticed and have only increased in number during the summers of 2018 and 2019, which had little precipitation and were warmer than average.
The bugs like to live in inner-city, urban areas. There is sufficient food and numerous hibernation opportunities there. So far, neither bug findings nor damage have been reported from the fruit and horticultural crops under observation in North Württemberg. However, it can be assumed that this will change in the next vegetation period. There have been reports of bug damage to table pears from southern Baden for two years. Switzerland and northern Italy have been reporting considerable crop losses on pome fruit, stone fruit, grapes and berry crops for some time. The marmorated stink bug is not very choosy in its search for food. Corn, soy, cucumbers, tomatoes, peppers and various fruit-bearing ornamental trees and shrubs are also on the menu of Halyomorpha halys, the scientific name of the animal. In total, there are over 300 plant species from all areas of cultivation that are potential host plants.
The insect most probably came to Europe in 1998 with a delivery of roof tiles from Beijing for a Chinese garden in Zurich. From there, it slowly spread through Switzerland to Basel, Bern and Schaffhausen. In the past, it has been found in Germany mainly along the Rhine Graben and at Lake Constance. Although the bug can fly very well, it also likes to travel long distances by plane, train and truck. It came to Italy and Georgia in wooden crates and other freight material. It was probably introduced to the USA directly from China in the same way in 1996. In the warm areas on the east coast of the USA and also in Italy, the bug forms two generations per year. North of the Alps, there is currently only one generation of bugs per year. Nevertheless, the reproduction rates are also considerable in our latitudes. Unlike in its countries of origin, China, Japan and Korea, Halyomorpha has no natural enemies here. The bugs can therefore reproduce and spread almost undisturbed in our country.
If the bugs appear in the home, they should be caught as carefully as possible. In Switzerland, where they have been up to mischief for a long time, they are called "stink bugs" for a reason. In the USA they are called "stink bugs": stink bugs spray a long-lasting and foul-smelling secretion when they feel threatened and even more so when they are crushed.
