The Function of the Antennae inRhodnius Prolixus(Hemiptera) and the Mechanism of Orientation to the Host

Anyone who has handled the blood-sucking bugs, Triatoma or Rhodnius, must have observed that they are often attracted to the sides of their jars at places where these have been warmed by recent handling, and that they will probe such spots vigorously with the proboscis. This behaviour suggests that they are attracted to their host mainly by warmth1—a belief which is supported by the recent observations of Rivnay (1932) on the bed bug (Cimex) and of Hase (1932) on various Triatomidae. Further, the movements of the antennae, which precede the location of the host, suggest that these carry the sense organs concerned ; and we were led to undertake the present work because it seemed possible that Rhodnius might prove a favourable subject in which to study both the function of the antennae, and the mechanism by which they secure the orientation of the insect in relation to its host. More particularly we hoped to define this mechanism in terms of the current theories of orientation (Loeb, 1918; Kühn, 1919; Fraenkel, 1931).