Cellular immune reactions of the sunn pest, Eurygaster integriceps, to the entomopathogenic fungus, Beauveria bassiana and its secondary metabolites

Abstract

In this study, five morphological types of circulating hemocytes were recognized in the hemolymph of the adult sunn pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae), namely prohemocytes, plasmatocytes, granulocytes, adipohemocytes, and oenocytoids. The effects of the secondary metabolites of the entomopathogenic fungus Beauveria bassiana on cellular immune defenses of Eurygaster integriceps were investigated. The results showed that the fungal secondary metabolites inhibited phagocytic activity of E. integriceps hemocytes and hampered nodule formation. A reduction of phenoloxidase activity was also observed. The data suggest that B. bassiana produce secondary metabolites that disable several immune mechanisms allowing the fungus to overcome and then kill its host. This characteristic makes B. bassiana a promising model for biological control of insect pests such as E. integriceps.

Keywords: fungi , hemocyte, nodule formation, phagocytosis

Abbreviations: PO, prophenoloxidase; THC, total hemocyte count

Correspondence: ^a arash.zibaee@gmx.com, ^b alirezabandani@gmail.com, ^c rtalaei@ut.ac.ir, ^d davide.malagoli@unimore.it, *Corresponding author

Editor: Michael Strand was Editor of this paper.

Received: 1 November 2010 | Accepted: 17 April 2011 | Published: 19 October 2011

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 11, Number 138

Zibaee A, Bandani AR, Talaei-Hassanlouei R, Malagoli D. 2011. Cellular immune reactions of the sunn pest, Eurygaster integriceps, to the entomopathogenic fungus, Beauveria bassiana and its secondary metabolites. Journal of Insect Science 11:138 available online: insectscience.org/11.138