Indirect sperm transfer in prostigmatic mites from a phylogenetic viewpoint

The life cycle and parasitism of the European grasshopper mite Eutrombidium trigonum (Hermann 1804) (Prostigmata: Parasitengonae: Microthrombidiidae), a potential agent for biological control of grasshoppers (Saltatoria)

“…Observations on weakened larvae after 90 days' exposure to 5°C and the absence of parasitized hosts early in the year support this assumption. The spermatophore deposition in Eutrombidium is similar to that of Camerotrombidium rasum (Berlese) (Parasitengonae: Microthrombidiidae) as described by Witte (1991). Indirect sperm transfer represents the plesiomorphic condition of the Parasitengonae (Witte, 1984).…”

“…Their absence in cold and wet habitats suggests that dry conditions are common to all inhabited localities. The ability of spermatophores to take up water from subsaturated air humidities (known from several other parasitengone mites; Wendt and Witte, 1985;Witte, 1991) and the partial drought resistance of the eggs, promote mite survival in such habitats. Moreover, Eutrombidium displays a preponderantly endogaic way of life.…”

“…Since a number of economically important insect pests are parasitized by parasitengone larvae, species of this group are regarded as potential agents of biological control (Welbourn, 1983;Gerson and Smiley, 1990). Of the various species combined in the monophyletic taxon Parasitengonae (Witte, 1991), the velvet mite genus Eutrombidium is the most frequent parasite of grasshoppers (Huggans and Blickenstaff, 1966;Southcott, 1993) and is therefore regarded as being a tDeceased. 0168-8162 © 1996 Chapman & Hall promising candidate for the biological control of acridid pests (Welbourn, 1983).…”

Ultrastructural characteristics of the spermatophore in Isopoda Oniscidea (Crustacea)

“…The spermatophore of Oniscidea generally lacks this requisite because it does not form a continuous lining around the sperm bundle and it does not seem to guarantee effective protection against dry environments. This hypothesis, however, should be accurately tested since in some other groups of arthropods that form unsheathed spermatophores, the spermatophore matrix secretion is strongly hygroscopic and provides effective protection against desiccation (Witte, 1991;Witte & Doring, 1999). The only exception to these considerations is perhaps represented by L. italica, where the spermatophore forms a continuous and solid wall around the sperms, which are totally embedded in a conspicuous mass of matrix material.…”

Fine structure of the spermatophore and spermatozoa in inseminated females ofPergamasus mites (Acari: Gamasida: Pergamasidae)

“…In Anactinotrichida, however, only direct spermatophore transfer has yet been observed (Alberti, 1991;Evans, 1992;Alberti and Coons, 1999). The complexity of actinotrichid spermatophore structure is well known from light and electron microscopic studies (see, e.g., Griffiths and Boczek, 1977;Witaliñ ski, 1985;Alberti et al, 1991;Fernandezet al, 1991;Witte, 1991;Witte and Döring, 1999;Alberti and Coons, 1999). Among anactinotrichids, only tick spermatophores have been investigated by electron microscopy.…”