Zug, 26.07.2019

After ticks and Asian tiger mosquitoes, now brown marmorated stink bugs are causing problems


The people of Zug will be thinking they are facing a plague of insects this summer, what with the increased likelihood of being bitten by a tick, and tiger mosquitos only a few miles off the cantonal border to the north. As if this were not enough, now another insect problem has arisen in the form of brown marmorated stink bugs.


Indeed, as Raymond Gmünder, the head of the Cantonal Plant Protection Service and pro-rector of the Schluechthof Agricultural College and Advisory Centre in Cham, explained (photograph), these bugs, Halyomorpha halys, are the most dangerous ones in the canton; there is a related indigenous variety, though these are not so harmful.


Traps have been set for the insects in a pear tree at a plantation for such at the college, with lots of them found crawling along branches lured to them by a sex hormone.


The insect is not popular at all with agriculturalists as it pricks fruit such as pears with its proboscis, sucks on the flesh, leaving dimples on the fruit, thereby making them unmarketable. The expert said how shocked he had been in discovering the extent of the problem after embarking on investigating it last year.


So far, six traps have been set up, three in the college grounds and three others in Hünenberg, each trap catching between 20 and 48 of the beetles a week, about the same as last year. With some 80 hectares of land given over to fruit growing in the canton, it is not surprising why the beetles head here; they like vegetables too, but less land is given over to growing these. Unfortunately, such traps alone are not enough to control them, and experts are wondering what more can be done, insecticides only having a limited effect.


What the beetles also like, in addition to eating, is to live in areas close to human habitation, spending the winter in houses.


Apparently, these marmorated brown beetles were first found in Switzerland in 2004 by an individual near the Chinese Gardens in Zurich, where tiles from China had recently been imported.