Soil nutrient deficiencies can cause a variety of plant problems that range from malformed plants to a lack of head growth. Many insects are attracted to lettuce, including cutworms, which cut seedlings off at the soil line; wireworms and nematodes, which cause yellow, stunted plants; tarnished plant bugs and aphids, which cause yellow, distorted leaves; leafhoppers, which cause stunted growth and pale leaves; thrips, which turn leaves gray-green or silver; leafminers, which create tunnels within the leaves; flea beetles, which cut small holes in leaves and caterpillars, slugs and snails, which cut large holes in leaves. For example, the larvae of the ghost moth is a common pest of lettuce plants. Mammals, including rabbits and groundhogs, also eat the plants.Bradley, pp. 129–132. Lettuce contains several defensive compounds, including sesquiterpene lactones, and other natural phenolics such as flavonol and glycosides, which help to protect it against pests. Certain varieties contain more than others, and some selective breeding and genetic modification studies have focused on using this trait to identify and produce commercial varieties with increased pest resistance.
soil nutrient deficiencies can cause a variety of plant problems that range from malformed plants to a lack of head growth many insects are attracted to lettuce including cutworms which cut seedlings off at the soil line; wireworms and nematodes which cause yellow stunted plants; tarnished plant bugs and aphids which cause yellow distorted leaves; leafhoppers which cause stunted growth and pale leaves; thrips which turn leaves gray-green or silver; leafminers which create tunnels within the leaves; flea beetles which cut small holes in leaves and caterpillars slugs and snails which cut large holes in leaves for example the larvae of the ghost moth is a common pest of lettuce plants mammals including rabbits and groundhogs also eat the plantsbradley pp 129–132 lettuce contains several defensive compounds including sesquiterpene lactones and other natural phenolics such as flavonol and glycosides which help to protect it against pests certain varieties contain more than others and some selective breeding and genetic modification studies have focused on using this trait to identify and produce commercial varieties with increased pest resistance