Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-22T19:27:53.586Z Has data issue: false hasContentIssue false
  • English
  • Français

The relative abundance of the mealybug vectors (Hemiptera: Coccidae and Pseudococcidae) of Cocoa swollen shoot disease in Ghana

Published online by Cambridge University Press:  10 July 2009

M. Bigger
M. Bigger
Affiliation:
Cocoa Research Institute, P.O. Box 8, New Tafo, Ghana*
Get access Rights & Permissions [Opens in a new window]

Abstract

A census of the mealybug vectors of cocoa swollen shoot disease was made weekly on 238 Amazon cocoa trees at the Cocoa Research Institute, Tafo, Ghana, between 1971 and 1976. The six species encountered were ranked in descending order of abundance: Planococcoides njalensis (Laing), Planococcus citri (Risso), Phenacoccus hargreavesi (Laing), Ferrisia virgata (Ckll), Pseudococcus concavocerarii James, P. calceolariae (Mask.). Planococcoides njalensis occurred at a much higher density on infested trees than other species but was found on fewer trees than either Planococcus citri or Phenacoccus hargreavesi. Over 13-week periods the probability of finding a mealybug on a particular tree was 0·87 for Planococcus citri, 0·77 for Phenacoccus hargreavesi, 0·36 for F. virgata, 0·32 for Pseudococcus concavocerarii, 0·23 for Planococcoides njalensis and 0·05 for Pseudococcus calceolariae. The results suggest that the first four species are more mobile than Planococcoides njalensis and could be more important in the spread of disease than has previously been supposed.

Type
Original Articles
Information
Bulletin of Entomological Research , Volume 71 , Issue 3 , September 1981 , pp. 435 - 448
Copyright
Copyright © Cambridge University Press 1981

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bigger, M. (1973). Distribution of mealybugs within the tree.—Ann. Rep. Cocoa Res. Inst., Ghana 1971–72, 115–116.Google Scholar
Box, H. E. (1945). Insect transmission of the “swollen-shoot” virus in West African cacao.—Nature, Lond. 155, 608–609.CrossRefGoogle Scholar
Campbell, C. A. M. (1975). The distribution of mealybug vectors of CSSV within trees.—pp. 67–71 in Kumar, R. (Ed.). Proceedings of the 4th Conference of West African Cocoa Entomologists, Zoology Department, University of Ghana, Legon, Ghana, 9th-13th December 1974.—202 pp. Legon, Ghana, Zoology Department, University Of Ghana.Google Scholar
Cornwell, P. B. (1960). Movements of the vectors of virus diseases of cacao in Ghana. II.—Wind movements and aerial dispersal.—Bull. ent. Res. 51, 175–201.CrossRefGoogle Scholar
Cotterell, G. S. (1943). Entomology. Swollen-shoot virus.—Rep. cent. Cocoa Res. Stn, Tafo 1938–42, 51–54.Google Scholar
Donald, R. G. (1955). Mealybug studies.—Ann. Rep. W. Afr. Cocoa Res. Inst. 1954–55, 101–104.Google Scholar
Igwebe, E. C. K. (1966). The preferences shown by Planococcoides njalensis (Laing) and Ferrisiana virgata (Ckll.) for different feeding sites and its effect on their efficiency as vectors.—Ann. Rep. Cocoa Res. Inst., Nigeria 1964–65, 60–62.Google Scholar
Legg, J. T. & Bonney, J. K. (1966). Classification and comparison of isolate.—Rep. Cocoa Res. Inst., Tafo 1963–65, 27–29.Google Scholar
Posnette, A. F. (1940). Transmission of “swollen shoot” disease of cacao.—Trop. Agric., Trin. 17, 98.Google Scholar
Posnette, A. F. (1941). Swollen-shoot virus disease of cacao.—Trop. Agric., Trin. 18, 87–90.Google Scholar
Posnette, A. F. (1950). Virus diseases of cacao in West Africa. VII. Virus transmission by different vector species.—Ann. appl. Biol. 37, 378–384.Google Scholar
Posnette, A. F. & Robertson, N. F. (1950). Virus diseases of cacao in West Africa. VI. Vector investigations.—Ann. appl. Biol. 37, 363–377.Google Scholar
Posnette, A. F., Robertson, N. F. & Todd, J. McA. (1950). Virus diseases of cacao in West Africa. V. Alternative host plants.—Ann. appl. Biol. 37, 229–240.CrossRefGoogle Scholar
Posnette, A. F. & Strickland, A. H. (1948). Virus diseases of cacao in West Africa. III. Technique of insect transmission.—Ann. appl. Biol. 35, 53–63.CrossRefGoogle Scholar
Strickland, A. H. (1951 a). The entomology of swollen shoot of cacao. I.—The insect species involved, with notes on their biology.—Bull. ent. Res. 41, 725–748.CrossRefGoogle Scholar
Strickland, A. H. (1951 b). The entomology of swollen shoot of cacao. II.—The bionomics and ecology of the species involved.—Bull. ent. Res. 42, 65–103.CrossRefGoogle Scholar