African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6688

Full Length Research Paper

Studies on bio-ecology and voracity of leaf roller (Diaphania indica Saunders, Lepidoptera: Pyralidae) on pointed gourd (Trichosanthes dioica Roxb.)

P. Barma
  • P. Barma
  • Department of Agricultural Entomology, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal
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S. Jha
  • S. Jha
  • Department of Agricultural Entomology, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal
  • Google Scholar


  •  Received: 30 September 2013
  •  Accepted: 18 August 2014
  •  Published: 02 September 2014

Abstract

Field and laboratory studies have been carried out on the bio-ecology of Diaphania indica Saund. Correlation coefficient with all seven weather factors considered in the present study indicated that there existed significantly high negative correlation with five factors viz. temperature (°C), relative humidity (%), rainfall and soil temperature (°C) but bright sun shine hours that did bear significant weak positive correlation. Predictive models were developed from pooled data of two years’ (2008 and 2009) observations on population vis-à-vis weather factor; one with irrespective of whether they had significant effect on population performance or no, and another with the significant ones.  Biology of leaf roller larvae studied under laboratory condition done at temperature varying between 30 and 35°C showed that the two temperature regimes had little effects on duration of different developmental stages. The total developmental period was 16 to 22 days (20.3±1.76 days) in 30°C and 17 to 22 days (19.5±1.43 days) in 35°C. Consumption and efficiency of conversion of ingested food to biomass was worked out through established procedures. Consumption increased progressively through five larval instars from initially 3.74 to finally 81.25 and its conversion of biomass from 3.96 to 140.02 as indicated by indices.

 

Key words: Bio-ecology, voracity, correlation, predictive model, biology.