Hemostasis in larvae of Manduca sexta: formation of a fibrous coagulum by hemolymph proteins.

Little is known of the participation of insect hemolymph proteins in wound healing and clot formation. We describe the assembly of purified hemolymph protein from the tobacco hornworm into an extended fibrous coagulum in the absence of hemocytes. This coagulum resembles the clot formed from bovine fibrinogen and thrombin. Structural components of the coagulum are present in hemolymph, however, spontaneous assembly occurs only in hemolymph collected through a wound. The fibrous coagulum assembles from purified structural protein(s) following addition of a non-protein factor from hemolymph, which is also present in Grace's insect cell culture medium.