The Brown Marmorated Stink Bug (Halyomorpha halys) is an invasive insect originally from Asia that has become a widespread pest in North American gardens and agriculture. This shield-shaped insect is highly mobile and capable of feeding on over 100 species of plants, causing significant economic damage to crops. Understanding which plants strongly attract these pests is necessary for gardeners and farmers to implement effective management strategies. Identifying host plants is the first step in successful pest control due to the insect’s broad diet and ability to move between hosts throughout the season.
Identifying Primary Host Plants
The most attractive plants for the brown marmorated stink bug are those with developing fruits or seeds, which provide a soft, nutrient-rich food source. High-value tree fruits like peaches, apples, and pears are frequently targeted, often resulting in unmarketable produce. Stone fruits such as cherries and apricots are also susceptible, as are small fruits like raspberries and blackberries.
In the vegetable garden, common plants like tomatoes, peppers, and beans serve as primary hosts. Sweet corn is a significant draw, where the bugs feed directly on the developing kernels through the protective husk. Legumes such as green beans, lima beans, and soybeans are also attractive because the bugs seek out the soft, immature seeds developing within the pods.
Beyond cultivated crops, ornamental trees and common weeds act as temporary or early-season hosts. Species like the catalpa tree and certain maples host large populations of adult bugs in the spring after they emerge from overwintering sites. Weeds, including kudzu and thistle, provide food for the first generation of nymphs before they migrate to fruiting plants later in the summer.
Understanding Stink Bug Feeding Habits
Stink bugs are classified as piercing-sucking insects; they do not chew plant tissue but use a specialized, needle-like mouthpart called a stylet to access plant fluids. The insect inserts the stylet and injects digestive saliva, which liquefies the internal tissue. They then suck the resulting mixture of plant juices and partially digested cells back up.
This feeding mechanism causes distinct types of damage depending on the plant part affected. On firm fruits like apples and peaches, localized cell death and subsequent growth around the injury lead to a characteristic deformity known as “cat-facing.” This results in dimpled, sunken, or necrotic areas on the fruit surface.
When feeding on vegetables, the damage appears as cloudy spots or discolored areas on the skin of tomatoes and peppers. Beneath the surface, the injured area develops a thick, corky, white texture due to the plant’s reaction to the injected saliva. For row crops, feeding on developing seeds in corn or soybeans causes the seeds to shrivel, become discolored, or reduce in size, lowering the overall yield and quality of the harvest.
The attraction to plants is strongest during the insect’s developmental periods. Soft, developing plant tissue is crucial for the nymphs, which require easily accessible nutrients to grow through their various instars. The presence of soft, forming seeds and fruits dictates which plants they will aggregate on throughout the growing season.
Plant-Based Repellents and Diversion Strategies
Once highly attractive plants are identified, gardeners can employ plant-based strategies to deter or divert stink bugs away from their main crops. Several aromatic herbs and plants contain natural compounds that appear to repel these pests, making them useful for barrier planting. Plants such as garlic, mint, catnip, and marigolds can be strategically placed along the perimeter of a garden.
The strong odors, particularly the sulfur compounds in garlic and the menthol in mint, seem to confuse or discourage the insects from landing and feeding. Gardeners can use these plants as a living fence, or create a water-based spray from crushed garlic cloves to apply directly to susceptible plants as a topical repellent.
Another effective plant-focused solution is trap cropping, which involves planting a species highly attractive to the stink bug at a distance from the main garden. Crops like sunflowers, sorghum, or buckwheat can be planted specifically to draw the pests away from high-value vegetables and fruits. The idea is that the bugs will congregate on the trap crop, allowing for targeted removal or destruction of the highly infested plants, thus diverting pressure from the desired harvest.