Formation (A-D) and degradation (E-H) of the peritrophic matrix (PM) in various sand fly species.

<p>The thin PM separating the blood bolus (BB) from the midgut epithelium (ME) is indicated by the arrow. It appears first by 1h PBM in <i>S</i>. <i>schwetzi</i> (4A) and <i>P</i>. <i>papatasi</i> (4B), 6 h PBM in <i>P</i>. <i>orientalis</i> (4C) and 12h PBM in <i>P</i>. <i>argentipes</i> (4D). At the end of digestion, the bloodmeal remnants are still enclosed by intact PM in <i>S</i>. <i>schwetzi</i> on day 3 PBM (4E). In contrast, in the other species studied bloodmeal remnants leak to abdominal midgut through broken PM, in <i>P</i>. <i>papatasi</i> typically by day 4 PBM (4F), in <i>P</i>. <i>orientalis</i> by day 3 PBM (4G) and in <i>P</i>. <i>argentipes</i> by day 2 PBM (4H). Scale bar = 50 μm.