SEPARATION AND BEHAVIOR IN-VITRO OF HEMOCYTES FROM THE MOTH, PSEUDOPLUSIA-INCLUDENS

Hemocytes collected from larvae of Pseudoplusia includens (Lepidoptera : Noctuidae) were separated by centrifugation on Percoll cushions. The procedure resulted in 95% purity of plasmatocytes and greater than 99 % purity of granular and spherule cells. Medium supplemented with chic ken serum enhanced cell viability and promoted spreading of plasmatocy tes. Cell-free plasma and medium preconditioned by plasmatocytes or gr anular cells stabilized cells in vitro and also accelerated spreading of plasmatocytes relative to medium supplemented with chicken serum. O enocytoids were the only morphotype that exhibited endogenous phenolox idase activity, while granular cells and plasmatocytes were the only c ells that endocytosed fluorescent beads in vitro. Granular cells and p lasmatocytes ingested fluorescently labelled beads, both in mixed popu lations of hemocytes and after separation. Plasmatocytes were the only morphotype that encapsulated large foreign targets in vitro following separation. Separated granular cells attached and spread on the surfa ce of foreign targets but never formed a multilayered capsule.