The adults are typical bugs with a flat body about 6 mm (0.24 inch) long; their color varies from green to brown. The legs and antennae are comparatively long. The young nymphs are green.
All instars feed by sucking on buds, bolls, young stalks and leaves. More important than the physical damage by their piercing-sucking mouthparts is the toxic saliva they inject during punctures, which causes the plant tissue to perish. Numerous small lesions in form of small blackish-brown spots can be found, appearing first on young infested leaves. As the leaves continue to grow, they tear at these points, and gradually develop the typical symptoms, commonly referred to as "frisolée". In cases of severe infestation, internodes are elongated, and the plants shoot up.
The adult plant bugs overwinter under fallen leaves and other plant debris. In spring they emerge, feed on weeds and lay their eggs with their ovipositor into stalks and buds, which does not damage the tissue. After 8-10 days, the larvae hatch. Their development lasts 2-3 weeks. Lygus bugs are hemimetabolous like all Hemiptera. The 5 instars of nymphs are wingless, the adults, however, can fly very well.
In early summer, the first generation of adults appears and disperses into adjacent crops. Here, one or two further generations will develop, depending on the prevailing climatic conditions. When the host plant they have recently been feeding on becomes unavailable, Lygus spp. will migrate readily into other crops, causing a rapid population increase there.