Camphor scale

Pseudaonidia duplex (Cockerell) (Hemiptera: Diaspididae)

Orientation to pest

Camphor scale (also called camellia scale), Pseudaonidia duplex (Cockerell), is an invasive Asian scale found in the southern United States. The scale infests leaves, twigs and fruit of various plants, but especially the camphor tree (Cinnamomum camphora [L.] Sieb.). In Asia, it is a pest of tea plantations. In Louisiana, the scale has three generations per year and overwinters primarily as mated adult females.

Hosts commonly attacked

This scale feeds on over 200 different host plants in Louisiana alone, including the camphor-tree (C. camphora) and some species of citrus (Citrus). In Asia it is a pest of tea (Camellia sinensis [L.]Kuntze).

Distribution

The U.S. distribution of this scale reaches from Florida and Georgia, west to Texas.

Images of camphor scale

Lyle Buss, University of Florida, Bugwood.org 768x512 / 1536x1024 Lyle Buss, University of Florida, Bugwood.org 768x512 / 1536x1024	Lyle Buss, University of Florida, Bugwood.org 768x512 / 1536x1024
Figure 1. Camphor scale, Pseudaonidia duplex, adults; Adult and one nymph on fruit (left) and adults and several nymphs on foliage (right)	Figure 2. Camphor scales on Virginia creeper (Parthenocissus quinquefolia (L.) Planch.) leaf

Lyle Buss, University of Florida, Bugwood.org 768x512 / 1536x1024	Lyle Buss, University of Florida, Bugwood.org 768x512 / 1536x1024
Figure 3. Camphor scales on wax-myrtle (Myrica spp.), with scale covers turned over to reveal scale bodies (orange)	Figure 4. Camphor scales on wax-myrtle twig

Important biological control agents related to this pest species

In Taiwan in tea plantations, this scale is attacked by the parasitoid Neochrysocharis sp., which can cause 42-61% mortality (Shiao, 1978).

Web links for information on camphor scale

• Entomology Circular | Florida Department of Agriculture
  Has list of hosts
• Species Catalog on ScaleNet
  Complete list of all recorded natural enemies, hosts, and distribution records; also an index to all publications on this species

Articles

• Shiao, S. N. 1977. Bionomics of the camellia scale, Pseudaonidia duplex (Cockerell), in northern parts of Taiwan. I. Life history and mortality factors. Plant Protection Bulletin, Taiwan 19 (2): 65-77.
• Shiao, S. N. 1978. Bionomics of the camellia scale, Pseudaonidia duplex (Cockerell) (Homoptera: Diaspididae) in northern parts of Taiwan. II. Natural enemies. Plant Protection Bulletin, Taiwan 20 (3): 210-223.