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Distribution patterns, sample-size and sampling Earias spp. on cotton in Ludhiana (Punjab)*

Published online by Cambridge University Press:  19 September 2011

A. K. Chakravarthy
A. K. Chakravarthy
Affiliation:
Department of Entomology, Punjab Agricultural University, Ludhiana 141004, India
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Abstract

Eggs and larvae of the bollworms Earias spp. followed a uniform distribution on G 27, LD 133, LD 230 (Arboreum) and F 414 (hirsutum) cotton varieties in Ludhiana (Punjab). Clump distribution of Earias eggs and larvae on the four cotton varieties may result from environmental heterogeneity. Although Earias gravid females laid maximum eggs at the top (41–50 cm) plant canopy mostly, examination of the whole length of the plants is suggested for sampling Earias on the four varieties.

Sample sizes of 10 plants in arboreum and seven in the hirsutum variety resulted in reliable estimates of population at 5% risk level. Injured fruiting bodies and larval numbers were significantly and positively correlated.

Résumé

Les oeufs des larves des vers Earias spp. ont adopté une distribution uniforme sur les variétés de cotton G27, LD133, LD230, et F414 à Ludhiana (Punjab). Les oeufs et les larves ont atteint leurs nombres maximaux une fois que la plante atteignait sa hauteur maximale (41–50 cm). Quand les plantes étaient âgées de 110 jours, on a fait des prélèvements sur dix plantes pour garantir une estimation fiable de Earias spp. sur les quatre variétés de cotton. Il y avait une corrélation significative (r = 0,5807) au niveau de 5% entre le pourcentage de dégâts causés par Earias sur les structures fruitières et leurs nombres larvaires. Par conśequent, l'utilisation du pourcentage de structures fruitières endommagées pour le prélèvement des échantillons d'Earias est suggéré.

Keywords

Spatial patternsample sizecottonEarias spp.LudhianaModèle spatialgrandeur de l'échantilloncottonEarias sppLudhiana
Type
Research Articles
Information
International Journal of Tropical Insect Science , Volume 6 , Issue 4 , August 1985 , pp. 517 - 520
Copyright
Copyright © ICIPE 1985

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References

REFERENCES

Arbous, A. G. and Kerrich, J. E. (1951) Accident statistics and concept of accident proneness. Biometrics 7, 340–432.CrossRefGoogle Scholar
Dutt, G. R. and Patel, M. S. (1943) The cotton bollworms (Earias fabia Stoll, Platyedra gossypiella Saund, and Heliothis obsoleta Fabr.) in the Central provinces and Berar. Indian J. agric. Sci. 13, 1–17.Google Scholar
Hopkins, A. R., Onsager, J. A., Moore, R. F. and James, W. (1981) Comparison of spatial distribution of Heliothis spp. Larvae and injured squares in cotton as estimated by three sampling methods. J. econ. Ent. 74, 409–420.CrossRefGoogle Scholar
Katiyar, K. N. (1977) Impact of flowering sequence on the incidence of bollworms in some varieties of cotton. Indian J. Ent. 39, 324–332.Google Scholar
Khan, M. H. (1944) Studies on Earias species (the spotted bollworms of cotton) in the Punjab—1. The relative abundance of E. fabia Stoll and E. insulana Boisd. in various parts in relation to environmental conditions. Indian J. Ent. 6, 15–25.Google Scholar
Kuehl, R. O. and Fye, R. E. (1972) An analysis of the sampling distributions of cotton insects in Arizona. J. econ. Ent. 65, 855–860.CrossRefGoogle Scholar
Metwally, A. G. and Hasny, M. M. (1974) The perpendicular distribution of pink bollworm infestation at different levels of the cotton plant. Bull. Soc. ent. Egypte 58, 89–92.Google Scholar
Panse, V. G. and Sukhatme, P. V. (1967) Statistical Methods for Agricultural Workers, p. 361. Indian Council for Agricultural Research, New Delhi.Google Scholar
Punjab Agricultural University (PAU) (1980) Package of practices for kharif crops of Punjab. Punjab Agrie. Univ. Ludhiana, p. 188.Google Scholar
Pyke, B., Sterling, W. and Harstack, A. (1980) Beat and shake bucket sampling of cotton terminals for cotton fleahoppers, other pests and predators. Environ. Ent. 9, 572–576.CrossRefGoogle Scholar
Singh, H. (1978) Studies on the insect pest infestation in relation to phenology of arboreum cotton. M.Sc. thesis (unpublished), Punjab Agrie. Univ. Ludhiana, p. 54.Google Scholar
Sohi, G. S. (1964) Pests of cotton. In Entomology in India (Edited by Pant, N. C.), pp. 111–148. Entomological Society of India.Google Scholar
Southwood, T. R. E. (1978) Ecological Methods, p. 391. Methuen, London.Google Scholar
Vaissayre, M. (1976) Sequential sampling for the estimation with a fixed degree of precision of the population density of bollworms. Cotton Fibres Trop. 31, 327–331.Google Scholar
Wolfenbarger, D. A. (1977) Boll weevil, bollworm and tobacco budworm and fruiting structures of the cotton plant: number of plants that must be sampled at different square population and percentage damage. J. econ. Ent. 70, 791–793.CrossRefGoogle Scholar