Developmental and digestive flexibilities in the midgut of a polyphagous pest, the cotton bollworm, Helicoverpa armigera
Plant Molecular Biology Unit, Division of Biochemical Sciences, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008 (M.S.), India
Abstract
Developmental patterns and survival of the cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), a polyphagous insect pest, have been studied with reference to the effect of diet on major gut digestive enzymes (amylases, proteases, and lipases). Significant correlations between nutritional quality of the diet and larval and pupal mass were observed when H. armigera larvae were fed on various host plants viz. legumes (chickpea and pigeonpea), vegetables (tomato and okra), flowers (rose and marigold), and cereals (sorghum and maize). Larvae fed on diets rich in proteins and/or carbohydrates (pigeonpea, chickpea, maize, and sorghum) showed higher larval mass and developed more rapidly than larvae fed on diets with low protein and carbohydrate content (rose, marigold, okra, and tomato). Low calorific value diets like rose and marigold resulted in higher mortality (25-35%) of H. armigera. Even with highly varying development efficiency and larval/pupal survival rates, H. armigera populations feeding on different diets completed their life cycles. Digestive enzymes of H. armigera displayed variable expression levels and were found to be regulated on the basis of macromolecular composition of the diet. Post–ingestive adaptations operating at the gut level, in the form of controlled release of digestive enzymes, might be a key factor contributing to the physiological plasticity in H. armigera.
Keywords: amylases, larval performance, lipases, proteases
Correspondence:
a pj.sarate103@gmail.com,
b vatamhane@gmail.com,
c hemakotkar@gmail.com,
d neenarp@gmail.com,
e sw8nishi@gmail.com,
f vs.gupta@ncl.res.in,
g ap.giri@ncl.res.in, *Corresponding author, # these
authors contributed equally to the work
Editor: Allen Cohen was editor of this paper.
Received: 24 March 2011 | Accepted: 9 January 2012 | Published: 24 March 2012
Copyright: This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.
ISSN: 1536-2442 | Volume 12, Number 42
Sarate PJ, Tamhane VA, Kotkar HM, Ratnakaran N, Susan N, Gupta VS, Giri AP. 2012. Developmental and digestive flexibilities in the midgut of a polyphagous pest, the cotton bollworm, Helicoverpa armigera. Journal of Insect Science 12:42 available online: insectscience.org/12.42
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