WSU Extension

Hortsense

Camellia
 
Disease
Cold injury 
Flower and petal blight 
Leaf gall 
Oedema 
Ramorum leaf and shoot blight (Sudden oak death) 
Sooty mold (Black mold) 
Sunburn 
Virus 
Insect
Aphids 
Brown soft scale 
Cottony camellia scale 
Root weevils 



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Caption: Root weevil larval damage
Photo by: A.L. Antonelli
  
Camellia : Root weevils
(revision date: 1/27/2016)


Biology
Root weevils are small flightless beetles with a snout. The adults are black or mottled and approximately 1/4" long, depending on species. They feed on the leaves by crawling up the stems and chewing semicircular or irregular notches on the leaf margins. Adults begin feeding around June to August, depending on the species, but adult feeding does little damage. Larvae are white, legless grubs about 1/4"-3/8" long and are found in the soil around the roots of affected plants. They feed on the roots and can girdle and destroy roots, causing decline or death of plants.
Management Options


Non-Chemical Management
  • Using a flashlight at night, hand-pick and destroy the nocturnal adult beetles.
  • Apply beneficial nematodes which kill the larvae. They are used as a soil drench in moist soils over 52 F (late summer to early fall in western Washington). Use sufficient water and do not apply in direct sunlight.
Select non-chemical management options as your first choice!

Chemical Management

Apply when first signs of notching are noticed on new leaves. Monthly application may be needed. Cease after first hard frost. Beneficial nematodes can be ordered from certain nurseries. They can be applied to control the larval stage if soil temperatures are warmer than 52 degrees F. Do not apply nematodes in direct sunlight and be sure soil is saturated with water before application.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • Bonide Systemic Insect Control
    Active ingredient: acephate  |  EPA reg no: 239-2461-4
  • Naturalis L
    Active ingredient: Beauveria bassiana  |  EPA reg no: 53871-9
  • Safer Brand BioNEEM Multi-Purpose Insecticide & Repellent Conc [Organic]
    Active ingredient: azadirachtin  |  EPA reg no: 70051-6-42697
  • This list may not include all products registered for this use.
Images

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Caption: Root weevil larval damage
Photo by: A.L. Antonelli
Caption: Adult root weevil damage
Photo by: E.P. Breakey
Caption: Root weevil larvae
Photo by: A.L. Antonelli