DEVELOPMENT AND AGING OF THE SALIVARY-GLANDS OF ADULT FEMALE AEDES-AEGYPTI (L) AND AEDES-TOGOI (THEOBALD) MOSQUITOS (DIPTERA, CULICIDAE)

Histological sections of the salivary glands of adult female Aedes aegypti and Aedes togoi (Diptera : Culicidae), varying in age from less than 1 day to 48 days after emergence were examined by light microscopy. Following emergence, the glands underwent morphological differentiation and also enlarged as secretory product accumulated, especially in the posterior regions. Development was complete within about 3 days (A. aegypti) or 7 days (A. togoi). Ageing, which began between 10 and 15 days after emergence in both species, predominantly affected the posterior regions of the glands. Regression, involving loss of stored secretion and cytological evidence of reduced protein synthesis, was accompanied by degenerative changes including substantial cytoplasmic vacuolation and increased prominence of large cyst-like structures. Although, in general, both regression and degeneration increased with time, there was marked variation between one gland and another in the speed with which ageing changes progressed.