pH of the sand fly larval gut.

<p>Third instar sand fly larvae were fed with pH indicators Bromothymol blue (A) and Phenol red (B). Shown is the distribution of each indicator within live sand fly larvae guts, with the predicted pH for each area of the gut indicated. Live 3^rd instar sand fly larvae are shown from left (posterior or caudal setae) to right (anterior or head).