Setal losses in the dorsal hysterosoma of Plateremaeoidea (Acari: Oribatida) in the light of ontogenetic studies

Abstract

The Plateremaeoidea demonstrate highly differentiated patterns of dorsal setae on the hysterosoma because these setae are lost in protonymph and adult. Setal loss in protonymph always starts with setae of d-series, and occurs in order, continuing to the l-series and h-series. For example, Aleurodamaeus setosus (Berlese, 1883) and Al. africanus Pletzen, 1963 lose setae of d-series in protonymph, and eight pairs in adult (c-series, l-series, h ₂, h ₃), so four pairs of setae remain (h ₁, p-series). Arthrodamaeus reticulatus (Berlese, 1910), Gymnodamaeus bicostatus (C. L. Koch, 1836) and Jacotella neonominata Subías, 2004 lose also setae la and lm in protonymph, and four pairs (c-series, lp), five pairs (c-series, lp, h ₃) and six pairs (c-series, lp, h ₂, h ₃) in adults, respectively, so six pairs (h-, p-series), five pairs (h ₁, h ₂, p-series) and four pairs of setae (h ₁, p-series) remain, respectively. Licnodamaeus costula Grandjean, 1931 loses additionally seta lp, and Licnobelba latiflabellata (Paoli, 1908) also lose seta h ₂ in protonymph, and setae of c-series in adults, so six pairs of setae (h-series, p-series) remain in the former species, and four pairs (h ₁, p-series) in the latter species. Morphological characters of juveniles and adults of eight species of Plateremaeoidea are compared.

Keywords:

• Aleurodamaeus setosus
• Licnodamaeus costula
• Licnobelba latiflabellata
• juvenile stages
• loss of hysterosomal setae
• ontogeny

Acknowledgements

We express our gratitude to Prof. Dr R.A. Norton, State University of New York, Syracuse, USA, for supporting us with some references, thorough review of this manuscript and many valuable suggestions. We also thank the reviewers of this manuscript, for their thorough review, and for many helpful suggestions, which considerably improved this paper, and we are grateful to Dr Andrew Polaszek, co-editor of the Journal of Natural History, for his editorial suggestions.