Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-26T13:54:35.123Z Has data issue: false hasContentIssue false

Changes in the composition of the fauna associated with the cassava mealybug, Phenacoccus manihoti, following the introduction of the parasitoid Epidinocarsis lopezi

Published online by Cambridge University Press:  19 September 2011

P. Neuenschwander
Affiliation:
International Institute of Tropical Agriculture, Oyo Road, PMB 5320, Ibadan, Nigeria
W. N. O. Hammond
Affiliation:
International Institute of Tropical Agriculture, Oyo Road, PMB 5320, Ibadan, Nigeria
R. D. Hennessey
Affiliation:
Programme de Recherche Agricole et Vulgarisation, (RAV) B.P. 11635, Kinshasa, Zaire
Get access

Abstract

Over 130 species of insects were found in association with the cassava mealybug (CM), Phenacoccus manihoti, and its newly introduced parasitoid Epidinocarsis lopezi in Africa. As the CM in SW Nigeria declined under the influence of E. lopezi, this introduced wasp maintained densities of 2.8–3 per CM-infested tip early in the dry season and 1.3–1.6 per infested tip late in the dry season, but declined overall from 1.3 to 0.2 per randomly collected tip within 1 year. The decline of CM led to a sharp reduction in numbers of indigenous coccinellids, particularly of Hyperaspis spp. and to a lesser extent of Exochomus sp., due to competition with E. lopezi for the common food source. Numerous species of other polyphagous predators and parasitoids of coccinellids were found in low numbers. Indigenous primary parasitoids, Anagyrus spp., were rare, but their 10 spp. of hyperparasitoids were often reared from E. lopezi, with Prochiloneurus spp. and Chartocerus spp. being the most common. Hyperparasitism declined from 41.3% in March 1983 to 16.9% in Dec 1984 and proved to be positively density-dependent. The effects of hyperparasitoids on this biological control programme are discussed.

Résumé

Quelque 130 espèces d'insectes associées à la cochenille du manioc, Phenacoccus manihoti Mat.-Ferr. (Hom., Pseudococcidae) et à son parasitoïde récemment introduit, Epidinocarsis lopezi (De Santi) (Hym., Encyrtidae) ont été répertoriées en Afrique. L'introduction de la guêpe E. lopezi a entrainé le recul de la cochenille du manioc dans le sud-ouest du Nigéria et l'établissement du parasitoïde à la densité de 2,8-3 individus par apex infesté de cochenilles en début de saison sèche et de 1,3–1,6 individus lors d'infestations plus tardives. On a observé une baisse rapide, de 1,3 à 0,2 individus par apex choisi au hasard, au bout d'un an. Elle fut immédiatement suivie d'une réduction substantielle du nombre de coccinellidés indigènes, en particulier Hyperaspis spp. et, à un degré moindre, Exochomus sp., en raison de la compétition avec E. lopezi pour une source alimentaire commune. De nombreuses espèces d'autres prédateurs polyphages et de parasitoïdes des coccinellidés furent recueillis en petites quantités. Si les parasitoïdes primaires indigènes, Anagyrus spp., s'étaient raréfiés, dix espèces des hyperparasitoïdes qui leur sont associés, Prochiloneurus spp. et Chartocerus spp. parmi les plus communes, furent souvent observées sur E. lopezi. On nota une diminution de l'hyperparasitisme de 41,3% en mars 1983 à 16.9% en décembre 1984 qui s'avéra dépendre étroitement de la densité. L'impact des hyperparasitoïdes sur ce programme de lutte biologique est abordé.

Type
Symposium XI: Africa-wide Biological Control Programme of Cassava Pests
Copyright
Copyright © ICIPE 1987

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

REFERENCES

Bennett, F. D. (1981) Hyperparasitism in the practice of biological control. The Role of Hyperparasitism in Biological Control: a Symposium (Edited by Rosen, D.), pp. 4349. Div. Agric. Sci. Univ. Calif., Berkeley.Google Scholar
Boussienguet, J. (1986) Le complexe entomophage de la cochenille du manioc, Phenacoccus manihoti (Hom. Coccoidea Pseudococcidae) au Gabon. I. Inventaire faunistique et relations trophiques. Ann. Soc. Ent. Fr. (N.S.) 22, 3544.Google Scholar
Elliott, N. C., Simmons, G. A. and Haynes, D. L. (1986) Mortality of pupae of jack pine budworm (Lepidoptera Tortricidae) parasites and density dependence of hyperparasitism. Environ. Ent. 15, 662668.Google Scholar
Fabres, G. and Matile-Ferrero, D. (1980) Les entomophages inféodés à la cochenille du manioc, Phenacoccus manihoti (Hom. Coccoidea Pseudococcidae) en République Populaire du Congo. I. Les composantes de l'entomocoenose et leurs inter-relations. Ann. Soc. Ent. Fr. (N.S.) 16, 509515.CrossRefGoogle Scholar
Greathead, D. J., Lionnet, J. F. G., Lodos, N. and Whellan, J. A. (1971) A Review of Biological Control in the Ethiopian Region. Commonwealth Agric. Bur., Tech. Comm. 5.Google Scholar
Hagen, K. S. (1976) Role of nutrition in insect management. In Proc. Tall Timbers Conf. on Ecological Animal Control by Habitat Management, 28 Feb–1 March, 1974, Gainesville, Florida, pp. 221261.Google Scholar
Hassell, M. P. and Waage, J. K. (1984) Host-parasitoid population interactions. A. Rev. Em. 29, 89114.Google Scholar
Herren, H. R. and Lema, K. M. (1982) CMB—first successful releases. Biocontrol News and Info., C.A.B. 3, 1.Google Scholar
Herren, H. R., Neuenschwander, P., Hennessey, R. D., Hammond, W. N. O. and Lema, K. M. (1985) Biological control. Epidinocarsis lopezi in Africa. IITA Annual Report for 1984, 124127.Google Scholar
Lema, K. M. (1984) Indigenous predators. IITA Annual Report for 1983, p. 120. Ibadan, Nigeria.Google Scholar
Luck, R. F., Messenger, P. S. and Barbieri, J. F. (1981) The influence of hyperparasitism on the performance of biological control agents. The Role of Hyperparasitism in Biological Control: a Symposium. (Edited by Rosen, D.), pp. 3442. Div. Agric. Sci. Univ. Calif, Berkeley.Google Scholar
Matile-Ferrero, D. (1977) Une cochenille nouvelle nuisible au manioc en Afrique equatoriale, Phenacoccus manihoti n. sp. (Hom. Coccoidea Pseudococcidae). Am. Soc. Ent. Fr. (N.S.) 13, 145152.Google Scholar
Neuenschwander, P., Hennessey, R. D. and Herren, H. R. (1987) Food web of insects associated with the cassava mealybug, Phenacoccus manihoti (Homoptera: Pseudococcidae), and its introduced parasitoid Epidinocarsis lopezi (Hymenoptera: Encyrtidae), in Africa. Bull. Ent. Res. 77, 177189.CrossRefGoogle Scholar
Neuenschwander, P., Schulthess, F. and Madojemu, E. (1986) Experimental evaluation of the efficiency of Epidinocarsis lopezi, a parasitoid introduced into Africa against the cassava mealybug Phenacoccus manihoti. Ent. exp. appl. 42, 133138.CrossRefGoogle Scholar
PRONAM (1978) Rapport Annuel, Programme National Manioc. INERA/Dept. Agric. Zaire, (mimeograph).Google Scholar
Weseloh, R. M. (1983) Population sampling method for cocoons of the gypsy moth (Lepidoptera: Lymantriidae) parasite, Apanteles melanoscelus (Hymenoptera: Braconidae), and relationships of its population levels to predator- and hyperparasite-induced mortality. Environ. Ent. 12, 12281231.CrossRefGoogle Scholar