Fig. 2.

Scale used to score the degree of blood engorgement in female sand flies from hardly visible engorgement (I) to full engorgement (VI), with progressive redness and abdomen distension reflecting the volume of blood intake. On the right, the three different colour categories (R = fresh red, M = mixed, and B = black). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article).