Measuring up to 3.5 centimeters in length for queens, these hornets are easily recognizable. Their bodies are a combination of black and orange - yellow, with the yellow forming a border on the abdomen, hence the name. The robust build and powerful mandibles are clear signs of their predatory nature. They construct large, papery nests, usually in tree hollows or man - made structures, which can house hundreds of individuals.

In Europe, the yellow - bordered hornet has seen a significant decline, yet the reasons remain unclear. It could be due to habitat loss from urbanization and deforestation, changes in climate affecting their food sources, or increased use of pesticides. However, in North America, where it has been introduced, the situation is different. The introduced populations seem to be faring better, perhaps because they have found new ecological niches without facing the same level of threats as in their native land. This contrast in fortunes between the two regions makes the yellow - bordered hornet an interesting subject for further ecological study, as scientists strive to understand what factors are driving these population trends.