Table 2. The head widths (in millimeters) of all three larval instars of S. watsoni.

Instar	Max.	Min.	Mean	Stand. dev.
L1	0.392	0.270	0.329	0.017
L2	0.479	0.350	0.421	0.021
L3	0.582	0.451	0.522	0.021