Table 6

Predictions of male An. gambiae age-grade as a function of their morphology, as obtained from the optimally performing breakpoints model. Text indicates whether males of a particular trait combination would be classified as being ≤ 4 days old (YOUNG), or older (OLD). Numbers in parentheses give the probability of males with a particular trait combination being in the 'OLD' age group, with the model categorizing all males with a probability of lower < 0.5 as being 'YOUNG', and 0.5 ≥ as being 'OLD'. Following this classification guide, the age status of 'YOUNG' and 'OLD' male An. gambiae should be correctly predicted on 81% and 95% of occasions respectively.

Proportion of testis occupied by sperm reservoir

Age class as predicted by the optimal model (BREAKPOINTS)

Clear area absent

Clear area present

≤ 30%

YOUNG (0.26)

YOUNG (0.04)

31%–60%

YOUNG (0.31)

YOUNG (0.05)

61%–90%

OLD (0.93)

OLD (0.62)

> 91%

OLD (0.98)

OLD (0.98)

Huho et al. Malaria Journal 2006 5:62   doi:10.1186/1475-2875-5-62