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International Journal of Tropical Insect Science

, Volume 26, Issue 3, pp 183–189 | Cite as

Geographical distribution, population density and host plants of tef epilachna Chnootriba similis (Coleoptera: Coccinellidae) in Ethiopia

  • Yibrah BeyeneEmail author
  • Trond Hofsvang
  • Ferdu Azerefegne
  • Trygve Berg
Article

Abstract

A survey on the geographical distribution of Chnootriba similis (Thunberg), formerly known as Epilachna similis, was undertaken from 2001 to 2003 in the main cereal-growing areas of Ethiopia. The population density of the insect was estimated by sweep netting (100 sweeps/farm). In addition, more detailed studies on seasonal and annual fluctuations in population density of C. similis were carried out in southern Ethiopia between 2002 and 2003 by sampling 10 quadrants of 0.25m2 per farmer’s field. The damage levels were determined using scores of 0–9. The survey revealed that C. similis is widely distributed in different parts of the cereal-growing regions of Ethiopia. It was observed that the beetles had spread to altitudes ranging from 1217 to around 3000m asl. However, the variations in population densities of C. similis cannot be directly attributed to altitude, as highly differing population densities in similar altitudes of different locations were recorded. Annual and seasonal variations in population density were observed in different areas of the southern part of Ethiopia. These results suggest that C. similis has a sporadic nature and can occasionally build up to outbreak levels. Beetles fed on both cereals (barley, wheat, tef, maize, sorghum and finger millet) and wild grasses (Leersia hexandra (Sw.), Avena abyssinica (Hoechst) and Lolium temulentum (L.)). Population densities and damage levels on the cereal crops varied considerably with the highest densities and damage levels on barley.

Key words

Chnootriba similis geographical distribution cereals host plants damage levels population density Ethiopia 

Résumé

Une enquête sur la distribution géographique de Chnootriba similis (Thunberg), connu auparavant sous le nom d’Epilachna similis, a été menée de 2001 à 2003 dans les principales régions céréalières d’Ethiopie. La densité des populations de l’insecte a été estimée par des coups de filet (100 coups/ferme). Par ailleurs, une étude plus précise des fluctuations saisonnières et annuelles de la densité des populations de C. similis a été menée dans le sud éthiopien en 2002 et 2003 en échantillonnant 10 quadrants de 0,25m2 par parcelle. Le niveau des dégâts a été estimé à l’aide d’une échelle de 0 à 9. L’enquête indique que C. similis est commun dans la plupart des régions céréalières d’Ethiopie. On a constaté que la coccinelle a colonisé des altitudes comprises entre 1217 et 3000 m. Cependant, les variations de densité de populations de C. similis ne peuvent s’expliquer par l’altitude seule dans la mesure où des différences de densité très importantes ont été constatées à une même altitude. Des variations saisonnières et annuelles de densité de population ont été observées dans différentes zones du sud de l’Ethiopie. Ces résultats suggèrent que C. similis a une nature sporadique et peut occasionnellement pulluler. La coccinelle se nourrit aussi bien de céréales (orge, blé, tef, maı¨s, sorgho et mil), que de graminées sauvages (Leersia hexandra (Sw.), Avena abyssinica (Hoechst), Lolium temulentum (L.)). Les densités de population et le niveau de dégâts sur les céréales cultivées varient considérablement, les plus fortes densités de populations et le niveau de dégâts le plus élevé étant observés sur orge.

Mots clés

Chnootriba similis distribution géographique céréales plantes hôtes niveau de dégâts densité de population Ethiopie 

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References

  1. Abo M. E., Alegbijo M. D., Sy A. A. and Misari S. M. (2001) An overview of the mode of transmission, host plants and methods of detection of Rice Yellow Mottle Virus. Journal of Sustainable Agriculture 17, 19–36.CrossRefGoogle Scholar
  2. Alam M. S. (1992) A survey of rice insect pests in Nigeria. Tropical Pest Management 38, 115–118.CrossRefGoogle Scholar
  3. Crowe T. J. and Shitaye G. M. (1977) Crop Pest Handbook 3rd edn. Institute of Agricultural Research, Addis Ababa. 55 pp.Google Scholar
  4. Davis F. M., Ng S. S. and Williams W. P. (1992) Visual rating scales for screening whorl-stage corn for resistance to fall armyworm. Mississippi Agriculture and Forestry Experimental Station Technical Bulletin, 186. 9 pp.Google Scholar
  5. Haile A. and Ali K. (1985) A review of research on control of insect pests of small cereals in Ethiopia, pp. 57–55. In Review of Crop Protection Research in Ethiopia. Proceedings of the First Ethiopian Crop Protection Symposium. 4–7 February 1985, IAR, Addis Ababa, Ethiopia (Edited by T. Abate). United Printers, Addis Ababa, Ethiopia.Google Scholar
  6. Heinrichs E. A. (1991) Lowland rice insect pest populations and their effect on grain yields, WARDA Annual Report 1991. West Africa Development Association, Boukaké (Côte d’Ivoire), pp. 55–57.Google Scholar
  7. Hill B. G. (1966) Insects of cultivated and wild plants, Harar Province, Ethiopia: 1960–1964. Bulletin of Entomological Research 56, 659–670.CrossRefGoogle Scholar
  8. Hill D. S. and Waller J. M. (1988) Pests and Diseases of Tropical Crops, vol. 2. Longman Scientific and Technical, England. 432 pp.Google Scholar
  9. Jemal D., Kebede A., Admasu A., Hussen Y. and Abay B. (1995) Land use systems and soil conditions of Ethiopia. Ministry of Agriculture Land Use Study and Rural Technology Promotion Department, Addis Ababa 104 pp.Google Scholar
  10. Mengistu N., Tesfaye H. and Taffesse O. (1989) Agroecological Zones of Ethiopia. Ministry of Agriculture, Addis Ababa, Ethiopia. 81 pp.Google Scholar
  11. Moharram I. A., Al-Gasahem M. Y., Morshed A. E. and Al-Mezgage M. (1996) Collection and classification of insects and their natural enemies on cereal crops in Yemen. Arab Journal of Plant Protection 14, 47–53.Google Scholar
  12. Nwilene F. E. (1999) Current status and management of insect vectors of Rice Yellow Mottle Virus (RYMV) in Africa. Insect Science and Its Application 19, 179–185.Google Scholar
  13. Scheibelreiter G. and Inyang P. (1974) Epilachna similis Muls. (Coleoptera, Coccinellidae), a minor pest on maize in Ghana. Ghana Journal of Agricultural Sciences 7, 75–79.Google Scholar
  14. Schmutterer H. (1969) Pests of Crops in Northeast and Central Africa with Particular Reference to the Sudan. Gustav Fisher Verlag, Stuttgart. 266 pp.Google Scholar
  15. Schmutterer H. (1971) Contribution to the knowledge of the crop pest fauna in Ethiopia. Zeitschrift fur Angewandte Entomologie 67, 371–389.CrossRefGoogle Scholar
  16. Wale M. (1998) Outbreaks of tef epilachna (Epilachna similis) in wheat in the central Rift Valley of Ethiopia. Rachis 17, 65.Google Scholar

Copyright information

© ICIPE 2006

Authors and Affiliations

  • Yibrah Beyene
    • 1
    Email author
  • Trond Hofsvang
    • 2
  • Ferdu Azerefegne
    • 3
  • Trygve Berg
    • 4
  1. 1.Norwegian University of Life SciencesDepartment of Plant and Environmental SciencesÅsNorway
  2. 2.BioforskÅsNorway
  3. 3.Awassa College of AgricultureDebub UniversityAwassaEthiopia
  4. 4.University of Life Sciences (UMB)NORAGRICÅsNorway

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