Population dynamics and age grading of mosquitos.

The dynamics of a vector population follows a characteristic pattern determined by the normal or modified environmental conditions of the biotope and by vector behaviour. The wide use of the precise method of age grading developed by Detinova and Polovodova has led to the conclusion that the dynamics of the various age groups may indicate behavioural, environmental, and epidemiological trends and changes and their significance. Age grading is useful for the qualitative assessment of vector density in general and of man-mosquito contact from the operational and epidemiological points of view, but only when sampling in time and space and the processing of the material collected have been correctly performed.

Methods for dissecting dry insects and insects preserved in fixative solutions or by refrigeration.

The methods described in this paper for the dissection of dry and preserved insects have been used for several years on various species, mainly mosquitos. In the past, dry or partially dry mosquitos found in traps or in the laboratory had to be discarded. By softening these insects in a detergent solution, however, it is possible to make most observations in the same way as on fresh material. The preservation of insects in the dry state, in a fixative, or in the refrigerator after collection enables much larger samples to be studied; the whole of the material can be examined and the work can be done when time permits. In addition, material can be sent to central laboratories far from the place of collection, and infected insects can be kept in stock for teaching purposes.