This tool is part of the Citrus Resource

Citrus Pests

 

Comstock mealybug

 

Scientific name

 

Pseudococcus comstocki (Hemiptera: Pseudococcidae)

Other common names

 

Japanese mealybug

Similar species

 

Pseudococcus apodemus

citrus mealybug, Planococcus citri
The Comstock mealybug can be distinguished by a thicker wax cover than the more common citrus mealybug.

grape mealybug, Pseudococcus maritimus

Odermatt mealybug, Pseudococcus odermatti

Distribution

 

United States: California, Connecticut, Delaware, Georgia, Illinois, Indiana, Louisiana, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, South Carolina, Virginia, and West Virginia.

Worldwide: Asia, Central and South America, Europe, and North America.

Native to Japan.

Diagnostic characteristics

 
Adult females
  • 2.5 mm (0.1 in.) to 5 mm (0.20 in.) length.
  • Pink to reddish-brown visible only between the body segments, the rest of the insect is covered in mealy white wax.
  • No line between the head and tail is visible on the top of the insect.
  • Elongate, oval with well-developed legs.
  • Wingless.
  • 17 straight and thin wax filaments on the sides; two pairs of filaments at the rear (posterior) of the insect are the longest at 1/4 to 2/3 body length.
  • The ovisac contains and protects newly-laid eggs and is kept underneath the body.
Adult males
  • Less than 1 mm (less than 0.1 in.) in length.
  • Reddish-brown. < LI>Gnat-like with two long tail-like filaments as long or longer than the entire body.
  • Delicate wings, appearing almost veinless.
  • Antennae with ten segments.
  • Three pairs of eyes and no mouthparts.
Immature females
  • Three nymphal instars.
  • 0.3 mm (less than 0.1 in.) to 2.5 mm (0.1 in.) in length.
  • Salmon color initially, darkening to light brown with age.
  • Oval and flattened.
Immature males
  • Five nymphal instars.
  • Approximately 3 mm (0.12 in.) long.
  • Orange-yellowish with less wax covering.
  • First instar is a small and oval crawling stage.
  • Third instar called "pre-pupa" and spins silken coccon.
  • Later instars contained within coccoon.
Eggs
  • 0.3 mm (less than 0.1 in.) long and 0.17 mm (less than 0.1 in.) wide.
  • Ranges from bright orange-yellow to pinkish brown.
  • Eggs are laid in masses under bark crevices or fruit calyxes.

Hosts

 
Citrus hosts
  • lemon, Citrus limon
Non-citrus hosts

Primarily infests deciduous fruit trees and ornamentals.

  • banana, Musa spp.
  • boxwood, Buxus sempervirens
  • Fatsia spp.
  • jasmine, Jasmium officinale
  • mulberry, Morus spp.
  • peach, Prunus persica
  • pear, Pyrus communis
  • pomegranate, Punica granatum
  • privet, Ligustrum spp.
  • umbrella catalpa, Catalpa spp.

Host damage

 
Fruits
  • Infestation can cause reduced yield and lowered fruit quality.
  • May retard or delay ripening.
  • Honeydew excreted by mealybugs coats the outside of fruit and promotes the growth of sooty mold fungus that inhibits photosynthesis, weakens the plant, and makes fruit unattractive.
Leaves
  • Lowered growth and vitality.

Biology

 

Eggs are oviposited under bark crevices, pruning cuts, or other protected areas. In the spring, eggs hatch into mobile first instar nymphs, known as crawlers. Crawlers seek out leaves and shoots to feed upon until they mature in the late summer. The adults lay eggs, and a second generation hatches in approximately 11 days. The young females mature by late fall and lay eggs capable of overwintering in some temperate areas. Occasionally, the nymphs and adults are able to overwinter.

Comments

 

All phloem-feeding, honeydew-producing pests have the potential to be tended by ants. The ants feed on the honeydew excreted by the pest and protect the pest from natural enemies. This protection can disrupt biological control programs.

References

 

Borkhseniusa, N.S. 1948. Notes on Pseudococcus comstocki (Kuw.) and some allied species (Homoptera: Coccoidea), with descriptions of three new species. Bull. Entomol. Res. 39: 417-421. Cambridge University Press, Cambridge England.

Gill, F.J. (ed.). 1999. California plant pest & disease report. California Department of Food and Agriculture - Plant Pest Diagnostics Center. pp. 76-77. (http://www.cdfa.ca.gov/phpps/ppd/PDF/CPPDR_1999_18_5-6.pdf).

Grafton-Cardwell, E.E. 2008. How to manage pests: U.C. pest management guidelines: Citrus - citrus mealybugs, citrus mealybug: Planococcus citri. U.C. IPM Pest Management Guidelines: Citrus U.C. A.N.R. Pub. 3441. (http://www.ipm.ucdavis.edu/PMG/r107300511.html).

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).

Reuther, W., E.C. Calavan, and G.E. Carman (eds.). 1978. The citrus industry: Crop protection. Univ. of California, Div. Agric. Nat. Resources.

Spangler, S.M., and A. Agnello. 1991. Comstock mealybug insect identification sheet. (http://www.nysipm.cornell.edu/factsheets/treefruit/pests/cmb/cmb.asp).

Walgenbach, J., A. S. Napier, and S. Schoof. 2007. Southeastern apple production entomology fact sheet: Comstock Mealybug Pseudococcus comstocki (Kuwana).(http://www.ces.ncsu.edu/fletcher/programs/apple/entomology/insects-mites/CMBfact.html).

Authors

 

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

 

Citrus Pests
Content last updated June, 2012
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