Insect larvae feed on the roots of plants underground. Landscape lighting will not deter grubs. They mature into beetles, such as Japanese beetles that are visible flying around plants in daylight. Look for dry patches of lawn or areas where animals have been digging up the lawn. White, C-shaped larvae, about 3/4 inch in size, are common pests found in grass-root systems. Treatment is usually insecticide. Preventative treatment with nematodes is also effective.
Larvae feed on the lawn in spring and fall. As larvae mature into beetles, they will be visible as flying insects or on garden plants. Beetles mate in summer and burrow underground to lay their eggs. These eggs hatch and larvae begin feeding and continue until November. Larvae then become dormant and overwinter in cells underground. As they grow, they eat the roots of turf and other plants. Summer brown patches of grass are one sign of their presence. Turf that pulls up in rolls is another.
The timing of treating an infestation is important. Smaller larvae can do less damage and can be eradicated in spring and early summer. the typical method is with pesticides specific to the plant or pest and watering this well down into the lawn. Preventative application of nematodes is best done in the spring and again in the fall. Many commercial insecticides are available for grub infestation.
Summer is a good time to be looking for beetles. One method of preventing mating is to look for beetles, such as Japanese beetles, on plants. Knock these insects off into a jar of soapy water. Keep at this practice throughout July and August and you will reduce the new larvae produced. Landscape lighting may attract some insects and thus help in this process of eradicating beetles. Beetle traps may attract more beetles and are generally not recommended.
Landscape lighting is often installed to accent property areas. It can help set an evening mood with low lighting for sitting outside or in the garden. Safety along walkways is another purpose. This lighting can be either solar or low voltage and not expensive to operate or install. Most lights are low to the ground and about 8 to 12 inches tall. Some offer adjustable beams that can be aimed at specific plants.
Gardens and ponds are common home landscape features. The soil around them may include grubs and other pests that attract mammals such as raccoons, deer and skunks. These animals are destructive while pawing and digging for grubs. Motion sensitive landscape lighting may deter them from your garden, or at least alert you to their browsing.