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Seasonal population fluctuations of cowpea aphid Aphis craccivora koch and its predatory coccinellids

Published online by Cambridge University Press:  19 September 2011

J. Srikanth
Affiliation:
Department of Entomology, University of Agricultural Sciences G.K.V.K., Bangalore 560 065, India
N. H. Lakkundi
Affiliation:
Department of Entomology, University of Agricultural Sciences G.K.V.K., Bangalore 560 065, India
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Abstract

In two study seasons, viz. summer (March to May) and “kharlf” (August to October) 1984 at Bangalore, India, populations of Aphis craccivora Koch on cowpea increased rapidly with crop growth and their peak coincided with peak pod formation. The activity of predatory coccinellids started 1 to 3 weeks after the appearance of aphids. The peak predator population more or less coincided with the peak aphid population. Highly significant positive correlations were found between weekly aphid and predator populations in the two seasons. The prey to predator ratio reached higher values 2 weeks after the incidence of the aphid, during peak pod formation stage and at the time of harvest. Amongst the predatory coccinellids, Menochilus sexmaculatus (F.) was predominant in both seasons constituting 77–88% and 83–95% of total predator population during summer and “kharif”, respectively. The study demonstrated a prey-dependent predator growth, often lagging behind that of the prey, pressing the need for alternate control methods that can be integrated into the management strategy considering the weather factors such as rainfall.

Résumé

Une etude faite en ètè (Mars–Mai) et entre les mois d'Avril et Octobre 1984 a Bangalore en Inde sur les populations d'Aphis craccivora Koch sur les pois a donné les resultats suivants. Les populations d'A. craccivora Koch augmentaient rapidement avec les cultures en croissance et que d'autre part les pics des insects coincidaient avec ceux de la formation de la cosse de cette plante. L'activité de coccinellides connu comme predateur commencait une à deux semaines après l'apparence des aphides. Le pic de la population des predateurs coincidait avec celui de la population des aphides. Des correlations significatives et positives entre les populations d'aphides et de predateurs pendant une semaine existaient durant les deux saisons. La proportion entre la proie et le predateur a atteint les valeurs maximales deux semaines après l'incidence des aphides, pendant le stage de la formation des cosses ainsi que pendant la recolte. Parmis les coccinellides predateurs–Menochilus sexmaculatus (F.) etait predominant pendant les deux saisons et constituaient respectivement 77–88% et 83–95% de la population totale des predateurs. Cette etude demontra une croissance des predateurs dependante de celle de la proie. Des strategies nouvelles sont necessaires pour lutter contre l'A. craccivora Koch parceque leur nombre croit plus vite que celui du predateur.

Type
Research Articles
Copyright
Copyright © ICIPE 1990

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References

REFERENCES

Butani, P. G. and Bharodia, R. K. (1984) Rektion of groundnut aphid population with its natural predator, ladybird beetles. Gujarat agric. Univ. Res. J. 9, 1274.Google Scholar
Gargav, V. P. and Verma, S. N. (1980) Studies on the toxicity of modern insecticides on vegetable aphids, jassids, their predators and parasites. Final Tech. Rep., IN-ARS-21, PL-480 Project (USDA) Jawaharlal Nehru Krishi Viswa Vidyalaya, Jabalpur, India. 55 pp.Google Scholar
Khan, M. Q. and Hussain, M. (1965) Role of coccinellid and syrphid predators in biological control of groundnut aphid. Indian Oilseeds J. 9, 6770.Google Scholar
Mathew, K. P., Thomas, M. J. and Nair, M. R. G. K. (1971) Population fluctuations of the pea aphid in relation to climate and predators. Agric. Res. J. Kerala 9, 2326.Google Scholar
Patel, R. C., Yadav, D. N. and Patel, J. R. (1976) Natural control of groundnut aphid, Aphis craccivora Koch, in Central Gujarat. Curr. Sci. 45, 3435.Google Scholar
Saharia, D. (1980a) Some aspects of the biology of coccinellid predators associated with Aphis craccivora Koch on cowpea. J. Res. Assam agric. Univ. 1, 8289.Google Scholar
Saharia, D. (1980b) Natural regulation of population of Aphis craccivora Koch on cowpea. J. Res. Assam agric. Univ. 1, 171176.Google Scholar
Singh, S. R. (1978) Resistance to pests of cowpea in Nigeria. In Pests of GrainLegumes:Ecology and Control (Edited by Singh, S.R., van Emden, H.F. and Ajibola Taylor, T.), pp. 267279. Academic Press, London and New York.Google Scholar
Srikanth, J. and Lakkundi, N. H. (1988) A method for estimating populations of Aphis craccivora Koch on cowpea. Trop. Pest Manage. 34, 335337.Google Scholar