A note on the defence reactions of insects to Protozoa

Abstract

It is well known that the defence reactions of insects to metazoan parasites are principally cellular rather than humoral; and it has recently been shown that the habitual parasitoids of an insect have means of resisting or avoiding the defence reactions of their host (Salt, 1968). Those two findings suffest that it may be necessary to re-examine the situation with regard to protozoan parasites, including some genera for which insects act as vectors between vertebrate hosts. Two examples will serve to draw attention to the problems involved.