Stink bugs are recognizable insects often found in gardens and agricultural settings, known for their distinctive shield shape and the odor they release when disturbed. Their presence can be a concern for homeowners and farmers alike due to their feeding habits, which directly impact plant health and crop quality. This article explores their primary dietary preferences, the plants they consume, and their feeding methods, offering insight into their environmental interaction and the challenges they pose.
Primary Plant-Based Diet
Most stink bugs are polyphagous, meaning they consume a wide variety of plants. Their diet primarily consists of plant materials, including fruits, vegetables, and ornamental plants found in gardens and fields. Newly hatched stink bugs often begin by feeding on weeds and grasses, gradually expanding their diet to include more diverse plant tissues as they mature into adults. This broad diet allows them to thrive in various environments, making them highly adaptable pests. Their opportunistic feeding habits mean they will readily switch food sources depending on availability and plant development.
Stink bugs possess specialized mouthparts designed for feeding on plants, known as piercing-sucking mouthparts. This elongated tube, sometimes referred to as a stylet, allows them to penetrate tough plant surfaces like leaves, stems, and the skin of fruits. They then extract plant sap and nutrients from internal plant tissues. This feeding mechanism is highly efficient, enabling them to access liquid sustenance within a broad range of host plants. This efficient feeding mechanism allows them to impact numerous crop types.
Specific Food Sources and Preferred Hosts
Stink bugs, particularly species like the brown marmorated stink bug, target a wide array of specific plants. Common garden fruits and vegetables are frequently consumed, including tomatoes, peppers, corn, and beans. They also feed on popular tree fruits such as apples, peaches, pears, and various berries. Soybeans are another significant food source, concerning for agricultural production. Their diet also includes grains like rice and cabbage.
Beyond common produce, stink bugs feed on a range of other plants, from young seedlings to mature plants. This includes field crops like cotton and sorghum, as well as nuts such as pecans. Ornamental plants, including sunflowers, maple trees, magnolias, Eastern rosebud, holly, and mimosa, can also serve as hosts, extending their reach beyond edible crops. While preferences vary among species, common pest species have a broad diet, adapting to available vegetation throughout the growing season. They feed on any available part of the plant, including pods, fruits, and flowers, depending on the plant’s growth stage.
How Their Feeding Impacts Plants
The feeding activities of stink bugs can cause significant damage to plants and their produce, impacting both aesthetic appeal and marketability. When a stink bug pierces a plant, it injects saliva into the tissue before extracting sap. This saliva contains digestive enzymes that break down plant cells, leading to localized damage around the feeding site. On fruits, this often results in symptoms such as dimpling, discoloration, or scarring on the surface. Damaged fruits may develop a “cat-facing” appearance, characterized by sunken, distorted, or corky areas that render them unmarketable.
Beyond fruits, stink bug feeding can also affect leaves and stems, leading to broader plant health issues. Necrotic spots, dead or discolored areas, can appear on leaves, sometimes accompanied by wilting or yellowing of foliage. This continuous extraction of sap weakens the entire plant, potentially leading to stunted growth or premature leaf drop. The cumulative effect of feeding can significantly reduce yields and make crops unsellable. Additionally, feeding wounds can create entry points for secondary infections by plant pathogens, further compromising plant vitality.