Fig wax scale

Scientific name

Ceroplastes rusci (Hemiptera: Coccidae)

Other common names

citrus wax scale

Similar species

barnacle scale, Ceroplastes cirripediformis

Chinese wax scale, Ceroplastes sinensis

Distribution

United States: Florida.

Worldwide: Africa, Asia, Australia, Central America, the Caribbean, Mediterranean region, Pacific Islands, and South America.

Native to Africa.

Diagnostic characteristics

Adults

• Females are 4 - 5 mm (0.16 - 0.2 in.) in length, and 3 - 4 mm (0.12- 0.16 in.) in width.
• Males are 1.3 mm (less than 0.1 in.) in length and 0.3 - 0.4 mm (less than 0.1 in.) in width.
• Body is reddish-brown, covered with a thick red-tinged, beige, or grayish-white wax covering.
• Oval or pentagonal and globular.
• Only males have clear (hyaline) wings with a wingspan of 0.75 - 1.0 mm (less than 0.1 in.).
• Antennae are six-segmented in females; ten-segmented in males. Thread-like (filiform), about 1/3 total body length.
• Adult females are typically used for identification purposes.

Immatures

• Three nymphal instars.
• 1 - 1.3 mm (less than 0.1 in.) in length.
• Brown.
• Star-like due to wax production.

Eggs

• 0.32 mm (less than 0.1 in.) in length, and 0.23 mm (less than 0.1 in.) in width.
• Light yellow, later become rusty or cinnamon-colored.
• Ovoid.
• Laid in chamber under the adult, not in a protective ovisacovisac:
  structure attached to the body that contains eggs; produced by many scale insects
  .

Hosts

Citrus hosts

• grapefruit, Citrus paradisi
• lemon, Citrus limon
• sour orange, Citrus aurantium

Non-citrus hosts

This pest has a very wide host rangehost range:
the range of species that a particular organism can feed on to achieve successful growth and reproduction
, including many with economic significance. A partial list includes:

• avocado, Persea americana
• Ficus spp.
• grape, Vitis spp.
• lychee, Litchi chinensis
• mango, Mangifera indica
• mulberry, Morus spp.
• sweet potato, Ipomoea batatas

Host damage

Fruits

• Occasionally attacks and damages fruit.
• Honeydew honeydew:
  the sugar-rich waste product excreted by aphids, mealybugs, and scales insects as a result of feeding on the phloem of plants
  excreted by scales coats the outside of fruit and promotes the growth of sooty mold fungus that inhibits photosynthesis, weakens the plant, and makes fruit unattractive.

Leaves

• Yellowing and loss of foliage.

Twigs

• Attacks young shoots, sometimes causing branch dieback.

Biology

Females overwinter on twigs. First instars emerge from eggs as crawlers and locate a leaf surface on which to feed. After approximately one month, the nymphs migrate to leaf petioles or new shoots to complete their life cycle. Adult females lose their wax coating so that they appear brown in color and are usually found on tree branches. One to two generations are reported annually.

Comments

All phloem-feeding, honeydew-producing pests have the potential to be tended by ants. The ants feed on the honeydewhoneydew:
the sugar-rich waste product excreted by aphids, mealybugs, and scales insects as a result of feeding on the phloem of plants
excreted by the pest and protect the pest from natural enemies. This protection can disrupt biological control programs.

Fig wax scale is reported to transmit the grapevine leaf-roll virus.

References

Ben-Dov, Y. 1993. A systematic catalogue of the soft scale insects of the world. Flora and Fauna Handbook No. 9. Sandhill Crane Press: Gainesville, FL.

Eberling, W. 1959. Subtropical fruit pests. Univ. Calif., Div. Agric. Sci.: Berkeley, CA.

Flint, M.L. 1999. Pests of the garden and small farm: a grower's guide to using less pesticide. Univ. of California Press: Berkley, CA.

Gill, R.J. 1997. Coccid pests of important crops: Citrus, pp. 207-215. In Y. Ben-Dov, C.J. Hodgson (eds.). World Crop Pests, Vol. 7B, Soft scale insects - their biology, natural enemies and control. Elsevier Science, B.V.

Hamon, A.B., and G.J. Mason. 1997. Fig wax scale, Ceroplastes rusci (L.), in Florida (Homoptera: Coccoidea: Coccidae). Entomol. Cir. 380. Fla. Dept. Agric. Consumer Svcs.

Mahfoudhi, N., M. Digiaro, M.H. Dhouibi. 2009. Transmission of grapevine leafroll viruses by Planococcus ficus (Hemiptera: Pseudococcidae) and Ceroplastes rusci (Hemiptera: Coccidae) Plant Dis. 93: 999-1002.

Mannion, C. 2008. Exotic pests - What to look for: Fig wax scale (Ceroplastes rusci). (http://edis.ifas.ufl.edu/IN344).

Miller, G.L., and D.R. Miller. 2003. Invasiveinvasive:
term used to describe species that are not native and have the ability to adversely effect habitats they invade either ecologically or economically
soft scales (Hemiptera: Coccidae), and their threat to U.S. agriculture. Proc. Entomol. Soc. Wash. 105: 832-846. (http://www.sel.barc.usda.gov/Coccoidea/MillerMi2003.pdf).

Miller, D.R., A. Rung, G.L. Venable, and R.J. Gill. 2007. Scale Insects: Identification tools for species of quarantine significance. CBIT Publishing, Queensland, Australia (http://www.sel.barc.usda.gov/ScaleKeys/ScaleInsectsHome/ScaleInsectsHome.html).

Rainato, A., and G. Pellizzari. 2010. The adult male and male nymphal instars of Ceroplastes rusci (Linnaeus) (Hemiptera: Coccoidea: Coccidae). Zootaxa 2357: 50-62. (http://www.mapress.com/zootaxa/2010/f/z02357p062f.pdf).

Authors

Martin, K.W., J.A. Weeks, A.C. Hodges, and N.C. Leppla