699 Journal of the Egyptian Society of Parasitology, Vol. 41, No. 3, December 2011 J. Egypt .Soc. Parasitol., 41 (3), 2011 :699– 714 INTERACTIONS OF SPODOPTERA LITTORALIS HAEMOCYTES FOL- LOWING INJECTION WITH THE ENTOMOPATHOGENIC FUNGI: BEAUVERIA BASSIANA AND NOMURAEA RILEYI By WESAM S. MESHRIF 1 , MARKO ROHLFS 2 , MOHAMED A. M. HEGAZI 1 , EMAD M. S. BARAKAT 3 , AMAL I. SEIF 1 AND MAGDI G. SHEHATA 3 Department of Zoology 1 , Faculty of Science, Tanta University, Tanta, Egypt; Department of Animal Ecology 2 , J.F. Blumenbach Institute of Zoolo- gy and Anthropology, University of Goettingen, Goettingen, Germany and Department of Entomology 3 , Faculty of Science, Ain Shams University, Cairo 11566, Egypt Abstract This study compared the cellular interactions of Spodoptera littoralis haemocytes with two virulence-different entomopathogenic fungi: Beauveria bassiana and Nomuraea rileyi. Using light and transmission microscopy, five types of haemo- cytes namely, prohaemocytes (PRs), plasmatocytes (PLs), granulocytes (GRs), spherule cells (SPs) and oenocytoids (OEs) were identified in the 6 th instar larvae. PRs and PLs were found in the haemopoietic tissue. Intra-haemocoelic injection of blastospores induced ultrastructural alterations in the cytoplasm and nuclei of cir- culating haemocytes of treated larvae. Different responses were observed in the populations of haemocyte types follow- ing injection with the tested fungi. The most important changes were the decrease of the numbers of GRs accompanied with increase in SPs at 12-48h following in- jection with B. bassiana, whereas, a decrease of PLs with a commitment increase in SPs and OEs were observed at most time intervals after injection with N. rileyi. Both fungi provoked a decrease of the total number of haemocytes at 48h followed by an increase at 72h post-injection. In vivo assay showed that the GRs and PLs actively phagocytised fungal blastospores. There was a time-dependent decrease and increase in the phagocytosis activity after injection of B. bassiana and N. rileyi, respectively. In B. bassiana-injected insects, the numbers of nodules increased significantly at 6-48h in comparison with the controls post-injection. In N. rileyi-injected insects, nodules increased signifi- cantly only at 72h post-injection. No cellular encapsulation was observed in any of the examined insects. Keywords: Cotton leaf-worm, haemocytes, and entomopathogenic fungi. Corresponding email: wmeshrif@science.tanta.edu.eg ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------