Histology and ultrastructure of the glands associated with the porose areas on the gnathosoma of Rhipicephalus evertsi evertsi before and during oviposition.

Histological and electronmicroscopical studies have shown that the subcuticular tissue associated with the porose areas of female Rhipicephalus evertsi evertsi consists of paired multicellular, alveolar and lobularly arranged glands. At least two types of cells are clearly distinguishable, according with their location. Proximally, in direct association with the pores, cells with small and long nuclei are present. These cells are aligned along large, elongated lumina containing numerous microvilli and extend deep into the cuticular pores. They are separated from the extraintegumental space by cuticular valves. The distal gland sections are characterized by cells with large nuclei which are mostly arranged in the form of rosettes. These cells, which function as secretory cells, contain many mitochondria, smooth and rough endoplasmic reticulum and membrane-lined vesicles. The glands are always present in female ticks and their dorso-ventral extension increases continuously with feeding, reaching a maximum depth during oviposition.