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The effect of some cowpea varieties on the development and survival of larvae of the seed moth, Cydia ptychora (Meyrick) (Lepidoptera: Tortricidae)

Published online by Cambridge University Press:  10 July 2009

R. M. Perrin
Affiliation:
Imperial College Field Station, Silwood Park, Ascot, Berkshire SL5 7PY, UK.

Abstract

In studies in Nigeria, survival and weight increase of the larvae of Cydia ptychora (Meyr.) were affected by the variety of cowpea (Vigna unguiculata) on which they fed. The weights of fifth-instar larvae immediately prior to pupation and the amount of fresh food ingested were similar on three varieties when loose seeds were fed, but in a more natural situation, larvae appeared to face a manoeuvrability problem in small pods, which resulted in reduced weight gain. Differences in weight due to diet were less pronounced in emerging adults. Larval mortality was greatest on two varieties with large pods and may have been related to the nutritional quality of mature seeds or the presence of toxic chemicals. Some first-instar larvae died during the pod-boring process, particularly in the variety Vita-5. Two known susceptible varieties produced a moderate-to-small degree of mortality and large females. Significantly greater weight was attained when larvae fed for five days on 10-day-old seed followed by 15-day-old seed, or on 15-day-old seed throughout, than on 15-day-old seed followed by dried seed, or on 10-day-old seed throughout. Ovipositing females seemingly select pods of an age that minimises exposure of young larvae to drying or fully dried seed, which is a relatively unsuitable diet.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1978

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References

references

Atwal, A. S. (1955). Influence of temperature, photoperiod, and food on the speed of development, longevity, fecundity, and other qualities of the diamond-back moth Plutella maculipennis (Curtis) (Lepidoptera: Tineidae).—Aust. J. Zool. 3, 185221.Google Scholar
House, H. L. (1972). Insect nutrition, pp. 513573 in Fiennes, R. N. T. W. (Ed.). Biology of nutrition. International encyclopaedia of food and nutrition, Vol. 18.—698 pp. Oxford, Pergamon.Google Scholar
Perrin, R. M. (1977). Studies on host plant selection by the cowpea seed moth, Cydia ptychora.—Ann. appl. Biol. 87, 175182.CrossRefGoogle Scholar
Perrin, R. M. (1978). Varietal differences in the susceptibility of cowpea to larvae of the seed moth, Cydia ptychora (Meyrick) (Lepidoptera: Tortricidae).—Bull. ent. Res. 68, 4756.Google Scholar
Rachie, K. O., Singh, S. R., Williams, R. J., Watt, E., Nangju, D., Wien, H. C. & Luse, R. A. (1976). Vita-4 cowpea.—Trop. Grain Legume Bull. no. 5, 4041.Google Scholar
Raman, K. V. (1975). Field and greenhouse screening for resistance to leafhoppers and thrips in cowpea, pp. 5557 in Luse, R. A. & Rachie, K. O. (Eds.). Proceedings of IITA collaborators’ meeting on grain legume improvement, 9–13 06, 1975, Ibadan.— Ibadan, International Institute of Tropical Agriculture.Google Scholar
Richards, O. W. & Waloff, N. (1954). Studies on the biology and population dynamics of British grasshoppers.—Anti-Locust Bull. no. 17, 1182.Google Scholar