About Beetles on Camellias
If you see holes in your camellia leaves, the likely suspects are twofold: the black vine weevil, Otiorhynchus sulcatus, or the cranberry rootworm beetle, Rhabdopterus picipes. The adult beetles feed primarily at night while their larvae feed on the root system, making them difficult to identify and control. The black vine weevil is most detrimental in its larval stage. It feeds on a variety of broad leaf evergreens as well as greenhouse specimens. Adults are equal opportunists and ravage both herbaceous and deciduous plants, and can be found through much of the northern U.S. and into Canada. This camellia vine weevil overwinters in the grub stage and then awakens in the spring as the soil warms. Adults feed and make holes in camellia leaves and then lay eggs at the base of the host plant in the late summer. Plants that have large numbers of grubs feeding on them can die. The cranberry rootworm beetle feeds on camellia leaves, leaving tell-tale narrow or crescent shaped holes in the foliage. New growth is most affected. Generally, the damage done by these pests is purely cosmetic.
Controlling Camellia Weevils
To control camellia vine weevils, use sticky traps placed on the ground around the plant. Shake the plant to dislodge the weevils. If you see adults adhere to the sticky traps, dig around the camellia and pick out the small, legless grubs. Dispatch these in a bowl of hot, soapy water. Also, keep the area surrounding the camellia free from debris that camellia vine weevils hide in during the day. If the insect infestation is severe and the above actions do not control it, spray the foliage with a natural insecticide like spinosad or bifenthrin, lambda cyhalothrin, or permethrin once flowering is done and feeding damage can be seen. You should also spray and saturate the leaf litter beneath the plants. Again, do not spray during bloom time, which will affect beneficial pollinating insects and follow the manufacturer’s instructions.
