Pest - JAPANESE BEETLE GRUBS (LARVAE)
Popillia japonica (Japanese Beetle)
Japanese beetle grubs (larvae), along with other large white grubs are the cause of a great deal of damage to residential lawns and over 400 different species of broad-leaf plants.
Japanese beetle go through six developmental stages: egg, three larval stages, pupa, and adult. Adult beetles emerge from the soil from late June through July. From emergence through mid-August, the females go through multiple cycles where they feed, mate, and lay eggs, until they each lay a total of 40 to 60 eggs. Larvae will hatch within 8 to 30 days, depending on the soil temperature. By early fall, most of the larvae will have reached their third stage of development and are prepared to hibernate through the winter at soil depths of 4 to 8 inches. Around mid April, or when soil temperatures reach approximately 60 degrees F, the grubs move close to the surface to feed.
The adults eat the leaf tissue between the veins, leaving stripped leaves that die quickly. Adults also attack flower buds and fruit. In the soil, the grubs can kill young plants but most commonly affect lawns and turf via grazing on the roots. Damaged grass yellows, as if under water stress. This destruction generally occurs in the spring before the larvae pupate and in the fall after the new larvae hatch. Grass damaged by beetle larvae feels spongy and can be pealed up like a carpet, revealing the grubs. Heavy infestations will kill grass in large patches.
Biological control of Japanese beetle larvae and other white grubs is possible with the Koppert products listed below.
For more information, ask our expert
Products in blue are Garden/Greenhouse Accessories.
LAWN AND TURF
TREES AND SHRUBS
KNOWING AND RECOGNIZING
MAGNIFYING LENS (LOUPE)
© Koppert Biological Systems, Inc. 2003