The structure of the Spiracles of the cattle tick, Boophilus microplus

Abstract

The structures of the nymphal and adult spiracles of the tick, Boophilus microplus, have been examined by means of serial sections and a stereoscan electron microscope. Contrary to the views of recent writers, the functional openings of the spiracle have been found to be holes or aeropyles in the peripheral part of the spiracular plate of the adult tick. The ostium of previous writers is shown to be the ecdysial tube, which is present only in the spiracles of adult ixodid ticks. After the nymphal-adult ecdysis, the ecdysial tube is closed. There is thus no ostium in this stage, as has been claimed by previous writers who supposed that the chief or only route for gas exchanges between the atrium of the spiracle and the ambient air was through the so-called ostium. The ecdysial process of the spiracles of ticks is shown to be basically similar to the ecdysial process of the spiracles of certain insects such as scarabaeid larvae and the larvae of some Diptera-Cyclorrhapha.

The spiracle glands in Ixodes ricinus (Linnaeus, 1758) (Acari: Ixodidae)

“…The gross morphology is in agreement with available descriptions of this and other ixodid species (Pugh et al, 1988;Pugh, 1997): the connection between the labyrinth, the sub-ostial space and the tracheal atrium is clearly visible. Moreover, we confirmed connections between the chambers by fenestrations, the closed condition of the "ostium" (Hinton, 1967; Pugh, 1997;Woolley, 1972) and the cuticular channels through the baseplate. The pedicels in I. ricinus have more than three edges, a condition typical for Ixodinae (Pugh, 1997).…”

“…In previous descriptions they were interpreted as sensory structures (Nordenskiöld, 1906;Roshdy and Hefnawy, 1973), as "Krobylophoren", organs of sensory and glandular function (Schulze, 1942), or as integumental glands (Arthur, 1956). Scanning and transmission electron microscopy (SEM and TEM) studies revealed more details on spiracle morphology (Hinton, 1967;Woolley, 1972) and supported a glandular nature of the cytoplasmic extensions (Baker, 1997;Sixl and Sixl-Voigt, 1974;Walker et al, 1996). Nevertheless, there are morphological differences in the spiracle glands of the species studied, and their function remains unclear.…”

The Biological Survey of Canada: A Personal History

“…In argasid ticks, the spiracular plate lacks pore-like chambers and goblets, and has a simple opening set in a hinged flap (Fig. 4) which passes directly into an atrial cavity (Hinton 1967).…”

Effect of Water Flooding on the Oviposition Capacity of Engorged Adult Females and Hatchability of Eggs of Dog Ticks:Rhipicephalus sanguineusandHaemaphysalis leachi leachi

“…Hinton [19] described the size and form of the aeropyles or spiracles of Boophilus. This author stated that the main function of the aeropyles is to block entry of water under field conditions.…”