Question 10
Look at the drawings 1 to 5 of the larvae of common freshwater insects (the drawing is not drawn to scale):
Identify each one in turn by using the key.
1) No legs: go to no. 2. Three pairs of legs present: go to no. 3.
2) Bristles on all segments: Culex. Bristles not present on all segment: Simulium.
3) One tail fillament: Sialis. Two tail fillament present: go to no 4.
4) Long fillament on head: Perla. Short fillament on head: Dyctisus.
Identify each one in turn by using the key.
1) No legs: go to no. 2. Three pairs of legs present: go to no. 3.
2) Bristles on all segments: Culex. Bristles not present on all segment: Simulium.
3) One tail fillament: Sialis. Two tail fillament present: go to no 4.
4) Long fillament on head: Perla. Short fillament on head: Dyctisus.