Brown Marmorated Stink Bug

• In autumn it gathers in hundreds on sunlit house walls and squeezes through any gap to spend the winter indoors, where it does no damage but is a considerable nuisance.
• Its defensive smell comes from glands on the thorax and is so persistent that it taints fruit and can ruin an entire vintage if the bugs get into the press.
• Biological control is being trialled with an Asian wasp that parasitises its eggs, and which has already turned up in Europe and North America of its own accord.
• It was first detected outside Asia in Allentown, Pennsylvania, in 1996, although it was mistaken for a native bug until 2001; it is now in more than forty US states and across much of Europe.
• It feeds on more than 170 plant species, from 45 families.
• In 2010 it caused losses of more than 37 million dollars in apples alone in the Mid-Atlantic region, and of 60 to 90 % of the peach crop in New Jersey.
• It enters houses en masse when the cold arrives, which makes it a domestic nuisance as well.
• It is being controlled with the samurai wasp, Trissolcus japonicus, which parasitises its eggs: in Trentino apple orchards parasitism rose from 8 % in 2020 to 41 % in 2023.

Habitat & environment

Fruit trees, crops and buildings in temperate regions

Sources consulted: https://es.wikipedia.org/wiki/Halyomorpha_halys

Best time: Autumn, when it looks for somewhere to overwinter and comes into houses