Entomophaga

, Volume 35, Issue 4, pp 515–526 | Cite as

Sustained biological control of the cassava mealybugPhenacoccus manihoti [Hom.: Pseudococcidae] byEpidinocarsis lopezi [Hym.: Encyrtidae] in Nigeria

  • W. N. O. Hammond
  • P. Neuenschwander
Article

Abstract

Following the successful introduction ofEpidinocarsis lopezi (De Santis) for biological control of the cassava mealybug (CM)Phenacoccus manihoti Mat.-Ferr. in southwestern Nigeria in 1981 and 1982, 11 groups of cassava fields were sampled every 2 weeks up to 1988 for impact assessment. After 1984, CM populations remained mostly below 10 per tip despite the presence of native hyperparasitoids, demonstrating the long-term success of biological control byE. lopezi in the region. Indigenous polyphagous coccinellids were found only during peak host densities, whereas the specificE. lopezi was common throughout the year. During some periods, percentage parasitism indicated delayed density dependence. Since 89% of all sampled cassava tips had no CM at all and the parasitisme is very mobile, parasitization rates were also calculated for individual infested tips (N=4,878). Parasitism increased slightly with host density on tips having between 1 and 10 CM of the 3rd and 4th instars, indicating positive density dependence. Such tips comprised 64% of all infested tips. At higher host densities, parasitism rates fell rapidly. The results are discussed in view of different theories on population regulation by biological control agents.

Key-Words

Phenacoccus manihoti Epidinocarsis lopezi Nigeria cassava biological control density dependence 

Résumé

Suite à l'introduction d'Epidinocarsis lopezi (De Santis) en vue d'une lutte biologique contre la cochenille du manioc (CM)Phenacoccus manihoti Mat.-Ferr. dans le sud-ouest du Nigéria en 1981 et 1982, 11 groupes de champs situés dans 2 régions ont été échantillonnés toutes les 2 semaines jusqu'en 1988, afin d'estimer l'impact de cet auxiliaire. Les populations du ravageur sont restées au-dessous de 10 CM par pousse la plupart du temps, malgré la présence d'hyperparasitoïdes indigènes, prouvant ainsi le succès continu de la lutte biologique parE. lopezi dans la région. Les coccinelles indigènes et polyphages n'ont été présentes que pendant les sommets de population de la CM, tandis que le parasitoïde spécifique était commun toute l'année. Pendant certaines périodes la courbe du parasitisme suggère une dépendance de la densité retardée. Comme 89% de toutes les pousses sont exemptes de la cochenille et comme le parasitoïde est très mobile, les taux de parasitisme ont été calculés sur la base des pousses individuelles. Malgré la grande variance des données couvrant 4 878 pousses infestées, une légére augmentation du parasitisme et, par conséquent, une dépendance positive de la densité sont constatées sur toutes les pousses ayant entre 1 et 10 CM du 3e et 4e stade. De telles pousses représentent 64% de toutes les pousses infestées. Aux densités d'hôte plus élevées le degré de parasitisme diminue rapidement. Les résultats sont discutés à la lumière des différentes théories sur la régulation des populations par les ennemies naturels.

Mots Clés

Phenacoccus manihoti Epidinocarsis lopezi manioc Nigéria lutte biologique dépendance de la densité 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Biassangama, A., Fabres, G. &Nénon, J.P. — 1988. Parasitisme au laboratoire et au champ d'Epidinocarsis (Apoanagyrus) lopezi [Hym.: Encyrtidae] auxiliaire exotique introduit au Congo pour la régulation de l'abondance dePhenacoccus manihoti [Hom.: Pseudococcidae]. —Entomophaga, 33, 453–465.CrossRefGoogle Scholar
  2. Dempster, J. P. &Pollard, E. — 1986. Spatial heterogeneity, stochasticity and the detection of density dependence in animal populations. —Oikos, 46, 413–416.Google Scholar
  3. Fabres, G. — 1981. Première quantification du phénomène de gradation des populations dePhenacoccus manihoti Matile-Ferrero [Hom.: Pseudococcidae] en République Populaire du Congo. —Agronomie, 1, 483–486.Google Scholar
  4. Fabres, G. — 1982. Bioécologie de la cochenille du manioc [Phenacoccus manihoti, Hom.: Pseudococcidae] en République Populaire du Congo. —Agron. Trop., 36, 369–377.Google Scholar
  5. Fabres, G. &Matile-Ferrero D. — 1980. Les entomophages inféodés à la cochenille du manioc,Phenacoccus manihoti [Hom.: Coccoidea, Pseudococcidae] en République Populaire du Congo. Les composantes de l'entomocœnose et leurs inter-relations. —Ann. Soc. Entomol. Fr. (N.S.), 16, 509–515.Google Scholar
  6. Gutierrez, A. P., Wermelinger, B., Schulthess, F., Baumgärtner, J. U., Herren, H.R., Ellis, C. K. &Yaninek, J. S.— 1988a. Analysis of biological control of cassava pests in Africa. I. Simulation of carbon, nitrogen and water dynamics in cassava. —J. Appl. Ecol., 25, 901–920.Google Scholar
  7. Gutierrez, A. P., Neuenschwander, P., Schulthess, F., Herren, H. R., Baumgärtner, J. U., Wermelinger, B., Löhr, B. &Ellis, C. K. —1988b. Analysis of biological control of cassava pests in Africa. II. Cassava mealybugPhenacoccus manihoti. —J. Appl. Ecol., 25, 921–940.Google Scholar
  8. Hammond, W. N. O., Neuenschwander, P. &Herren, H. R. — 1987. Impact of the exotic parasitoidEpidinocarsis lopezi on cassava mealybug [Phenacoccus manihoti] populations. —Insect Sci. Applic., 8, 887–891.Google Scholar
  9. Hammond, W. N. O., van Alphen, J. J. M., Neuenschwander, P. & van Dijken, M. J. — 1989. Aggregative and mutual interference in field populations ofEpidinocarsis lopezi (De Santis) [Hym.: Encyrtidae], a parasitoid of the cassava mealybug [Phenacoccus manihoti Mat.-Ferr.Hom.: Pseudococcidae]. —Oecologia (in press).Google Scholar
  10. Hassell, M. P. — 1978. The dynamics of arthropod predator prey systems. Monographs in population biology. —Princeton University Press, Princeton.Google Scholar
  11. Hassell, M. P. — 1984. Parasitism in patchy environments: inverse density dependence can be stabilizing. —I.M.A.J. J. math. appl. med. Biol., 1, 123–133.Google Scholar
  12. Hassell, M. P. — 1985. Insect natural enemies as regulating factors. —J. Anim. Ecol., 54, 323–334.Google Scholar
  13. Hennessey, R. D. &Muaka, T. — 1987. Field biology of the cassava mealybug,Phenacoccus manihoti and its natural enemies in Zaire. —Insect Sci. Applic., 8, 899–903.Google Scholar
  14. Herren, H. R. &Lema, K. M. — 1982. CMB-first successful releases. —Biocontrol News and Info. C.A.B., 3, 185.Google Scholar
  15. Herren, H. R., Neuenschwander, P., Hennessey, R. D. &Hammond, W. N. O. — 1987. Introduction and dispersal ofEpidinocarsis lopezi [Hym.: Encyrtidae], an exotic parasitoid of the cassava mealybug,Phenacoccus manihoti [Hom.: Pseudococcidae], in Africa. —Agric. Ecosyst. Environ., 19, 131–144.Google Scholar
  16. Huffaker, C. B. &Messenger, P. — 1964. The concept and significance of natural control. In: Biological control of insect pests and weeds (P. DeBach &E. I. Schlinger, eds.), pp. 74–117. —Chapman & Hall, London.Google Scholar
  17. Iziquel, Y. &LeRü, B. — 1989. Influence de l'hyperparasitisme sur les populations d'un hyménoptère encyrtidae,Epidinocarsis lopezi parasitoïde exotique de la cochenille du maniocPhenacoccus manihoti Mat.-Ferr. introduit au Congo. —Entomol. Exp. Appl., 52, 239–247.CrossRefGoogle Scholar
  18. Kraaijeveld, A. R. &van Alphen, J. J. M. — 1986. Host-stage selection and sex allocation byEpidinocarsis lopezi [Hymenoptera: Encyrtidae], a parasitoid of the cassava mealybug,Phenacoccus manihoti [Homoptera: Pseudococcidae]. —Med. Fac. Landbouww. Rijksuniv. Gent., 51, 1067–1078.Google Scholar
  19. Legner, E. F. — 1969. Distribution pattern of hosts and parasitisation bySpalangia drosophilae [Hymenoptera, Pteromalidae]. —Can. Entomol., 101, 551–557.Google Scholar
  20. Lema, K. M. &Herren, H. R. — 1985. Release and establishment in Nigeria ofEpidinocarsis lopezi, a parasitoid of the cassava mealybug,Phenacoccus manihoti. —Entomol. Exp. Appl., 38, 171–175.Google Scholar
  21. Lema, K. M., Herren, H. R. &Neuenschwander, P. — 1984. Impact ofE. lopezi on the CM. —IITA Ann. Rep., 1983, 119–120.Google Scholar
  22. LeRü, B. &Iziquel, Y. — 1988. Evaluation de l'incidence mécanique des pluies, à l'aide d'un simulateur de pluies, sur la dynamique de populations de la cochenille du manioc,Phenacoccus manihoti. — pp. 19–22, In La cochenille du manioc et sa Biocenose au Congo: 1985–1987. ORSTOM, Paris.Google Scholar
  23. LeRü, B., Iziquel, Y., Biassangama, A. &Kiyindou, A. — 1988. Comparaison des effectifs de la cochenille du maniocPhenacoccus manihoti avant et après introduction d'Epidinocarsis lopezi Encyrtidae americain, au Congo en 1982. — pp. 1–18, In: La cochenille du manioc et sa Biocenose au Congo: 1985–1987. ORSTOM, Paris.Google Scholar
  24. Löhr, B., Neuenschwander, P., Varela, A. M. &Santos, B. — 1989. Interactions between the female parasitoidEpidinocarsis lopezi (De Santis) [Hym.: Encyrtidae] and its host the cassava mealybug,Phenacoccus manihoti Matile-Ferrero [Hom.: Pseudococcidae]. —Z. Angew. Entomol., 105, 403–412.Google Scholar
  25. May, R. M. &Hassell, M. P. — 1988. Population dynamics and biological control. —Phil. Trans. R. Soc. Lond. B. 318, 129–169.Google Scholar
  26. Murdoch, W. W., Chesson, J. &Chesson, P. L. — 1985. Biological control in theory and practice. —Am. Nat., 125, 344–366.CrossRefGoogle Scholar
  27. Nadel, H. &van Alphen, J. J. M. — 1987. The role of host and host plant odours in the attraction of a parasitoid,Epidinocarsis lopezi, to the habitat of its host, the cassava mealybug,Phenacoccous manihoti. —Entomol. Exp. Appl., 45, 181–186.CrossRefGoogle Scholar
  28. Neuenschwander, P. &Hammond, W. N. O. — 1988. Natural enemy activity following the introduction ofEpidinocarsis lopezi [Hymenoptera: Encyrtidae] against the cassava meallybugPhenacoccus manihoti [Homoptera: Pseudococcidae], in southwestern Nigeria. —Environ. Entomol., 17, 894–902.Google Scholar
  29. Neuenschwander, P. &Herren, H. R. — 1988. Biological control of the cassava mealybug,Phenacoccus manihoti, by the exotic parasitoidEpidinocarsis lopezi in Africa. —Phil. Trans. R. Soc. Lond. B. 318, 319–333.Google Scholar
  30. Neuenschwander, P. &Madojemu, E. — 1986. Mortality of the cassava mealybug,Phenacoccus manihoti Mat.-Ferr. [Hom.: Pseudococcidae], associated with an attack byEpidinocarsis lopezi [Hym.: Encyrtidae]. —Mitt. schweiz. entomol. Ges., 59, 57–62.Google Scholar
  31. Neuenschwander, P., Hammond, W. N. O., Gutierrez, A. P., Cudjoe, A. R., Baumgärtner, J. U., Regev, U. &Adjakloe, R. — 1989a. Impact assessment of the biological control of the cassava mealybug,Phenacoccus manihoti Matile-Ferrero [Hemiptera: Pseudococcidae] by the introduced parasitoidEpidinocarsis lopezi (De Santis) [Hymenoptera: Encyrtidae]. —Bull. Entomol. Res., 79, 579–594.Google Scholar
  32. Neuenschwander, P., Haug, T., Ajuonu, O., Davis, H., Akinwumi, B. &Madojemu, E. — 1989b. Quality requirements in natural enemies used for inoculative release: Practical experience from a successful biological control programme. —Z. Angew. Entomol., 108, 409–420.Google Scholar
  33. Neuenschwander, P., Hennessey, R. D. &Herren, H. R. — 1987. Food web of insects associated with the cassava mealybugPhenacoccus manihoti Matile-Ferrero [Hemiptera: Pseudococcidae], and its introduced parasitoidEpidinocarsis lopezi [Hymenoptera: Encyrtidae], in Africa. —Bull. Entomol. Res., 77, 177–189.Google Scholar
  34. Neuenschwander, P., Schulthess, F. &Madojemu, E. — 1986. Experimental evaluation of the efficiency ofEpidinocarsis lopezi, a parasitoid introduced into Africa against the cassava mealybugPhenacoccus manihoti. —Entomol. Exp. Appl., 41, 133–138.Google Scholar
  35. Nsiama She, N. D. — 1987. Progrès enregistré en matière de lutte biologique contre la cochenille farineuse du manioc au Zaire, pp. 245–265. In: Séminaire sur les maladies et les ravageurs des principales cultures vivrières d'Afrique centrale, Bujumbura, 16–20 Feb. 1987.Google Scholar
  36. Odebiyi, J. A. &Bokonon-Ganta, A. H. — 1986. Biology ofEpidinocarsis (=Apoanagyrus) lopezi [Hymenoptera: Encyrtidae] an exotic parasite of cassava mealybug,Phenacoccus manihoti [Homoptera: Pseudococcidae] in Nigeria. —Entomophaga, 31, 251–260.Google Scholar
  37. Schulthess, F. — 1987. The interaction between cassava mealybugPhenacoccus manihoti (Mat.-Ferr.) populations and cassava (Manihot esculenta Crantz) as influenced by weather. —Ph. D.-thesis, Swiss Federal Institute of Technology, Zürich, Switzerland.Google Scholar
  38. Schulthess, F., Baumgärtner, J. U. &Herren, H. R. — 1987. Factors influencing the life table statistics of the cassava mealybugPhenacoccus manihoti. —Insect Sci. Applic., 8, 851–856.Google Scholar
  39. Schulthess, F., Baumgärtner, J. U. &Herren, H. R. — 1989. SamplingPhenacoccus manihoti in cassava fields in Nigeria. —Trop. Pest Managt., 35, 193–200.Google Scholar
  40. Stern, V. M., Smith, R. F. &van den Bosch, R. — 1959. The integration of chemical and biological control of the spotted alfalfa aphid. The integrated control concept. —Hilgardia, 29, 81–101.Google Scholar
  41. Taylor, L. R. — 1961. Aggregation, variance and the mean. —Nature, 189, 732–735.Google Scholar
  42. Van den Meiracker, R. A. F., Hammond, W. N. O. &van Alphen, J. J. M. — 1988. The role of kairomones in prey finding in the coccinellidsDiomus sp. andExochomus sp., predators of the cassava mealybug,Phenacoccus manihoti. —Med. Fac. Landbouww. Rijksuniv. Gent., 53, 1063–1077.Google Scholar
  43. Van Driesche, R. G. — 1983. Meaning of “percent parasitism” in studies of insect parasitoids. —Environ. Entomol., 12, 1611–1622.Google Scholar
  44. Waage, J. K. — 1983. Aggregation in field parasitoid populations: foraging time allocation by a population ofDiadegma [Hymenoptera, Ichneumonidae]. —Ecol. Entomol., 8, 447–453.Google Scholar

Copyright information

© Lavoisier Abonnements 1990

Authors and Affiliations

  • W. N. O. Hammond
    • 1
  • P. Neuenschwander
    • 1
  1. 1.Biological Control ProgrammeInternational Institute of Tropical AgricultureCotonouRépublique du Bénin

Personalised recommendations