The objectives of this morphometric study of Culex (Culex) saltanensis Dyar, 1928 larvae were to observe the continuous growth of siphon and cephalic capsule length and width in each instar, and to propose a linear equation to differentiate instars according to the size of both structures. Larvae obtained in laboratory at 27 ± 1ºC, photoperiod 14L:12D were studied. Larvae of the forth instar were collected on the field and compared with same instar larvae reared in the laboratory. Egg size and pigmentation pattern, first instar continuous growth, and differentiation of larval stages measurements were studied. Egg pigmentation patterns and the shapes of raft eggs differentiated specimens of C. saltanensis from Culex (Culex) quinquefasciatus Say, 1823 found in polluted pond water.
Instar; larva; measurement
