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WITHIN PLANT PREFERENCES OF LARVAE OF MAMESTRA CONFIGURATA (LEPIDOPTERA: NOCTUIDAE) FEEDING ON OILSEED RAPE1

Published online by Cambridge University Press:  31 May 2012

G. K. Bracken
G. K. Bracken
Affiliation:
Research Station, Agriculture Canada, Winnipeg, Manitoba R3T 2M9
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Abstract

The order of feeding preference on plant parts of rape (Brassica napus L.) by sixth instar (L6) larvae of bertha armyworm, Mamestra configurata Walker, in laboratory tests was leaves, bracts, immature pods, and mature pods. Field sampling showed that upper, immature pods are attacked with greater frequency than lower, more mature pods. In a greenhouse test, a slightly larger proportion of L6 larvae was recorded on inflorescences of rape plants during darkness than during light; the proportion of larvae found on the inflorescences was about 20%. Larvae pupated more quickly, formed heavier pupae, and gained more dry weight when fed exclusively from mid L4 on leaves than when fed mature or immature pods; mortality for larvae fed mature pods was 30% compared with none for larvae fed leaves or immature pods.The finding that pods are neither as preferred nor as adequate a dietary source as leaves is discussed in relation to the phenology of leaf retention of rape on the economic impact of bertha armyworm infestations.

Résumé

Dans des expériences de laboratoire, l'ordre de préférence dans la déprédation des parties de la plante de colza, Brassica napus L., par les larves de sixième stade (L6) de la légionnaire bertha, Mamestra configurata Walker, était : les feuilles, les bractées, les jeunes gousses et les gousses pleinement développées. L'échantillonnage sur le terrain montrait que les jeunes gousses, plus hautes, étaient attaquées plus souvent que les gousses inférieures, plus développées. Dans un essai en serre, on constatait une proportion légèrement supérieure de larves L6 sur les inflorescences de plantes de colza en période de noirceur qu'en période de clarté; la proportion de larves trouvées sur les inflorescence était d'environ 20%. La pupaison était plus rapide, les pupes plus lourdes et le gain de poids sec supérieur chez les larves nourries exclusivement de feuilles à partir du stage intermédiaire L4 que chez celles nourries de gousses entièrement développées ou non. La mortalité des larves nourries de gousses entièrement développées était de 30% comparativement à zéro pour celles nourries de jeunes gousses.La découverte que les gousses ne sont pas une source alimentaire aussi recherchée ni aussi appropriée que les feuilles est examinée en relation avec la phénologie de la rétention des feuilles de colza sur l'incidence économique des infestations de légionnaires bertha.

Type
Articles
Information
The Canadian Entomologist , Volume 116 , Issue 1 , January 1984 , pp. 45 - 49
Copyright
Copyright © Entomological Society of Canada 1984

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References

Bailey, C. G. 1976. A quantitative study of consumption and utilization of various diets in the bertha armyworm, Mamestra configurata (Lepidoptera: Noctuidae). Can. Ent. 108: 1319–1326.CrossRefGoogle Scholar
Bracken, G. K. and Bucher, G. E.. 1977. An estimate of the relation between density of bertha armyworm and yield loss on rapeseed, based on artificial infestations. J. econ. Ent. 70: 701–705.Google Scholar
Bucher, G. E. and Bracken, G. K.. 1976. The bertha armyworm. Mamestra configurata (Lepidoptera: Noctuidae). Artificial diet and rearing technique. Can. Ent. 108: 1327–1338.Google Scholar
Clarke, J. M. 1978. The effects of leaf removal on yield and yield components of Brassica napus. Can. J. Pl. Sci. 58: 1103–1105.Google Scholar
Harper, R. R. and Berkenkamp, B.. 1975. Revised growth-stage key for Brassica campestris and B. napus. Can. J. Pl. Sci. 55: 657–658.CrossRefGoogle Scholar
Hozyo, Y., Kato, S., and Kobayashi, H.. 1972. Photosynthetic activity of the pods of rape plants (Brassica napus L.) and the contribution of the pods to the ripening of rape seeds [in Japanese, English summary]. Proc. Crop Sci. Soc. Japan 41: 420–425.Google Scholar
Major, D. S., Bole, J. B., and Charnetski, W. A.. 1978. Distribution of photosynthates after 14CO2 assimilation by stems, leaves and pods of rape plants. Can. J. Pl. Sci. 58: 783–787.CrossRefGoogle Scholar
McWilliams, J. M. and Beland, G. L.. 1977. Bollworm: effect of soybean leaf age and pod maturity on development in the laboratory. Ann. ent. Soc. Am. 70: 214–216.Google Scholar
Moscardi, F., Barfield, C. S., and Allen, G. E.. 1981. Consumption and development of velvetbean caterpillar as influenced by soybean phenology. Environ. Ent. 10: 880–884.CrossRefGoogle Scholar
Mueller, A. J. and Engroff, B. W.. 1980. Effects of infestation levels of Heliothis zea on soybeans. J. econ. Ent. 73: 271–275.Google Scholar
Tayo, T. O. and Morgan, D. G.. 1975. Quantitative analysis of the growth, development and distribution of flowers and pods in oil seed rape (Brassica napus L.). J. agric. Sci. Camb. 85: 103–110.Google Scholar