HEMOCYTE SURFACE CHANGES IN THE MIGRATORY GRASSHOPPER, MELANOPLUS-SANGUINIPES IN RESPONSE TO WOUNDING AND INFECTION WITH BEAUVERIA-BASSIANA

Surface changes of hemocytes from the migratory grasshopper, Melanoplu s sanguinipes (Fab.), following wounding and/or infection with Beauver ia bassiana (Bals.) Vuillemin were assessed using fluorescein labelled wheat germ agglutinin (WGA) and concanavalin A (Con A). Binding was o bserved on outer wall of hemocytes when either Con A or WGA conjugates were tested. After infection there was an increase in the percentage of hemocytes which bound to WGA and which remained so for 24 h. Howeve r, after wounding this increase in binding subsided after only 1 h. Fu rthermore, it was found that the increase in WGA-binding occurred with in the first 15 min of wounding or infection. In addition, ConA bindin g in males only increased 3-fold in fungus-injected insects within 1 h of treatment and remained high for 24 h. These results indicated the presence of mannose (and/or glucose) residues (Con A specificity) and N-acetyl-D-glucosamine residues (wheat germ agglutinin; WGA specificit y) on outer wall surfaces of the hemocytes. The implications of these results in the immune response of M. sanguinipes to infection with B. bassiana are discussed.