Key to the pupae of Xenochironomus

1. Tergites II–V with bands in the median region with black shagreen.................. Xenochironomus xenolabis (Kieffer)

- Tergites II–V with anterior bands of brown shagreen.......................................................... 2

2. Sternites I and II with posterior bands of clear spines.......................................................... 3

- Sternites I and II without spines.................................................... Xenochironomus grini sp. n.

3. Pedes spurii A present in segment IV......................................................................4

- Pedes spurii A absent in segment IV.................................... Xenochironomus canterburyensis (Freeman)

4. Prealar tubercle present........................................ Xenochironomus ceciliae Roque et Trivinho-Strixino

- Prealar tubercle absent........................................................ Xenochironomus mendesi sp. n.

Key to the fourth-instar larvae of Xenochironomus

1. Labral sclerite 1 divided into two plates........................................ Xenochironomus xenolabis (Kieffer)

- Labral sclerite 1 undivided.............................................................................. 2

2. Mentum with even number of teeth.......................................................................3

- Mentum with odd number of teeth........................................................................4

3. Mentum with 12 teeth............................................................ Xenochironomus grini sp. n.

- Mentum with 16 teeth......................................................... Xenochironomus mendesi sp. n.

4. Median tooth of the mentum sutured.................................. Xenochironomus canterburyensis (Freeman) *

- Median tooth of the mentum simple............................. Xenochironomus ceciliae Roque et Trivinho-Strixino