Horning, as predatory insects from the Osowaty family (vespidae), are sensitive to chemical signals in their environmentwhich lead them to potential sources of food, reproductive places or victim. They are characterized by strong sensitivity to volatile organic compounds emitted by plants, especially in response to mechanical damage or feeding of other insects. They play an important role among these relationships Green volatile leaf compounds (GLV, Green Leaf Volatiles)such as (Z)-3-hexenol.
A study conducted in 2007 by scientists from the University of Wageningen in the Netherlands showed that (z) -3-hexenol is one of the main compounds attracting hornets. This substance has a characteristic “grassy” smell, which is emitted in large quantities by damaged plants. Hornet use their highly developed smell organs, located on the tentacles, to detect these chemical signals.
(Z) -3-hexenol, like other GLV, is a volatile alcohol, which quickly spreads in the air, creating “fragrance trail“. For hornets, this is a signal that there may be a victim in a given place that can be hunted, or a damaged plant that secretes sweet juices – another important element of their diet. Importantly, insects also react to complex fragrance mixtures. Plants emit entire bouquets of volatile organic compounds (VOC), which may vary depending on the plant species, the type of damage or even the time of day. Hornet are able to recognize these subtle differences, which allows them to precisely locate the signal source.
Plants from the butterfly family, i.e. Red clover, beans, peas or alfalfa, They are extremely attractive to the hornets due to their rich fragrance profile. The 2019 study, conducted at the University of Helsinki, showed that the red clover, especially in the vicinity of other plants, significantly increases the emissions (z) -3-hexenol when it is attacked by aphids or caterpillars. These compounds lure hornets, promising easy access to food – both insects feeding on plants and sweet vegetable juices.
Fruit plants, i.e. Raspberry, apple trees and pearsthey also attract hornets, especially when the fruits are overripe or damaged, because then they secrete sweet, fermenting fragrances. Damaged leaves and stems, which have been attacked e.g. by butterfly caterpillars, intensify GLV emissions, making such places in magnets for hornets. In gardens and orchards, it is worth monitoring the condition of plants to limit their damage.
Among the trees particularly attractive to the hornets stand out oakswhich emit green volatile leaf compounds (GLV) in response to bark and leaves damage. A study from 2024 from the University of Freiburg has shown that oaks attacked by gallows (insects) produce specific mixtures of volatile organic compounds that attract hornet to galas (growths created on oak leaves by galas). Similarly buk i clone (especially the ordinary maple) attract hornets when their leaves are damaged by caterpillars or aphids.
Jesion haughty It is particularly attractive to hornets thanks to the resin with a high sugar content, secreted by cracking shoots. This sticky substance provides them with food and at the same time serves as a material for building nests. On the other hand papillary birch Wee about them with a sweet juice they get into, gnawing young shoots or damaged bark. Lilac common In the period of flowering, it attracts hornets with an intense, sweet scent of nectar, rich in Terpenes that protect plants from pests. They attract pollinators or predators (hornets) to combat herbivores.
Plants with strong aromas, which are due to peppermint, basil, marjoram garlic, lavender, citruses i eucalyptus They drown out chemical signals attracting hornets. They secrete essential oils, i.e. menthol, Linalol and Cytronella, which will confuse insects, hindering them the location of food and materials for the construction of the nests. That is why it is worth planting these plants near houses, terraces or apiaries to create a natural fragrance barrier.
Horning can also be scared away by the smell roasted wood or incensebecause it is a signal for them, associated with a fire. You can also use fragrance traps with apple vinegar or sweet substanceswhich distract from places where their presence is undesirable. In addition, we should also avoid leaving food residues, especially sweet drinks or fruit, and regularly remove damaged plants to reduce the attractiveness of the environment for hornets.
