Revision of the Genus Afroleius Mahunka, 1984 (Acari: Oribatida) By Louise Coetzee Thesis submitted in fulfilment of the requirement for the degree Philosophicae Doctor in the Faculty of Natural and Agricultural Science, Department of Zoology & Entomology, University of the Free State Promoter: Prof. J.G. van As Co-promoter: Dr V.M. Behan-Pelletier January 2015 Declaration _____________________________________________________________________ I declare that this thesis, hereby handed in for the qualification Doctor of Philosophy in Zoology in the Faculty of Natural and Agricultural Sciences at the University of the Free State, is my own independent work and that I have not previously submitted the same work for a qualification at another university/faculty. __________________________ _____________________ Louise Coetzee Date “You are never too old to set another goal or to dream a new dream” C.S. Lewis Contents ____________________________________________________________________________ Introduction ................................................................................................................................. 1 Chapter 1 .................................................................................................................................. 19 Coetzee, L. & Tiedt, L.R. 2013. Overview of the genus Afroleius Mahunka, 1984 (Acari, Oribatida). In: Schausberger, P. (Ed.). Acari in a changing world: Proceedings of the 7th symposium of EURAAC, Vienna, 2012. Acarologia, 53(2): 163–173. Chapter 2 .................................................................................................................................. 31 Coetzee, L. 2013. New species of the genus Afroleius Mahunka, 1984 (Acari, Oribatida, Mycobatidae) from South Africa. Acta Zoologica Academiae Scientiarum Hungaricae, 59(4): 307–319. Chapter 3 .................................................................................................................................. 45 Coetzee, L. 2014. Rare new species of the genus Afroleius Mahunka, 1984 (Acari, Oribatida, Mycobatidae) from South Africa. Navorsinge van die Nasionale Museum, Bloemfontein, 30(5): 71–85. Chapter 4 .................................................................................................................................. 60 Coetzee, L. 2014. Afroleius floridus (Mahunka, 1985) comb. nov. and three new Afroleius Mahunka, 1984 species (Acari, Oribatida, Mycobatidae) from South Africa. Zootaxa 3889(4): 553–573. Chapter 5 .................................................................................................................................. 82 Coetzee, L. In Press. Key to the species of Afroleius Mahunka, 1984 (Acari, Oribatida, Punctoribatidae), recombination of A. polygonatus (Mahunka, 1985), description of A. lucidus sp.nov. and discussion of A. undulatus (Balogh, 1959). Systematic and Applied Acarology. Chapter 6 ................................................................................................................................ 112 Molecular Phylogeny of Afroleius Discussion ............................................................................................................................... 127 Acknowledgements ................................................................................................................. 141 Abstract ................................................................................................................................... 142 Opsomming .............................................................................................................................144 Introduction ____________________________________________________________________________ Background The invention of the microscope in the late seventeenth century opened up a whole new world for mankind. For the first time, inquisitive biologists could see organisms too small to be seen by the naked eye. In his historic book Micrographia, published in September 1665, Robert Hooke detailed his observations through a microscope. Hooke's spectacular images of the micro-world inspired a wide interest in the new science of microscopy. With the advancement of technology and improved optics, the study of micro-organisms became much more detailed and available to a large scientific community. Ancient Greeks were aware of akari and understood some of the effects these small creatures had on nature, but it was only from the late 1700s that they became more recognised. Linnaeus listed 29 species of Acarus in the 10th edition of his Systema Naturae (see Krantz & Walter 2009; Walter & Proctor 1999), four of them referable to Oribatida (Schatz 2002). From: Micrographia Robert Hooke 1665. Acarology—the study of mites—includes all taxa in “I observ'd in Oxford several of these little the arachnid subclass Acari. Mites are among the pretty creatures to wander to and fro ... “ ______________________ L. Coetzee | Introduction | 1 oldest of arthropod groups, with fossil evidence from the Devonian (380–400 mya) (Walter & Proctor 1999), when terrestrial vegetation began to flourish (Norton 1985). The earliest known oribatid mite fossils derive from the Middle Devonian Gilboa mudstones in New York State (Norton et al. 1988). Early in their evolutionary history oribatid mites became established in soil habitats and played an important role in soil ecology (Labandeira et al. 1997; Norton 1985; Schaefer et al. 2010). Mites, in the broad sense, have evolved to occupy almost all possible habitats—aquatic, arboreal, terrestrial and parasitic—and have developed a wide range of lifestyles (Walter & Proctor 1999). The Acari is divided into two superorders, namely Parasitiformes (including ticks) and Acariformes. The superorder Acariformes comprises those mites which Walter & Proctor (1999) call the “mite-like mites” and includes two orders, namely Trombidiformes (mainly plant and predatory mites) and Sarcoptiformes. The suborder Oribatida form the largest group within Sarcoptiformes (Krantz & Walter 2009). The suborder Oribatida includes the cohort Astigmatina, previously regarded as a suborder of Sarcoptiformes (as Astigmata). Norton (1994, 1998, 2007) explored the strong morphological evidence for the hypothesis that Astigmata originated from within Oribatida and this is supported by the molecular analysis of Dabert et al. (2010). However, the contradicting results of Domes et al. (2007) do not support the origin of Astigmata within Oribatida. Oribatid mites (excluding Astigmatina) are mostly organic decomposers. The vast majority inhabit the soil-litter system, while some are arboreal and a few are aquatic. Oribatid mites are small, ranging from 300–700 µm (with extremes from 150–2 000 µm), and while they lack in size, they make up in numbers. In organic soils they are often the dominant arthropod group (Behan et al. 1978; Nel & Ryke 1970; Norton & Behan-Pelletier 2009). Abundance and diversity of oribatids vary greatly according to soil conditions. As many as 200 000 individuals per m2 are commonly reported from Canadian soils, with extremes as high as 1 million (Behan-Pelletier 1993) and diversities of 100–150 species per m2 (Norton & Behan- ______________________ L. Coetzee | Introduction | 2 Pelletier 2009). South African soils do not support such high abundance or diversity. Hugo- Coetzee & Avenant (2011) recorded 49 species in Free State grasslands over a period of three years, with an average abundance of 2 600 individuals per m2 (litter and 5 cm-deep soil). Nel & Ryke (1970) investigated the abundance and diversity of soil fauna in two separate habitats (indigenous forest and sugarcane plantations) in KwaZulu-Natal (Indian Ocean Coastal Belt, see Mucina & Rutherford 2006); densities of on average 70 730 individuals per m2 in the forest and 13 800 individuals per m2 in sugarcane plantations were recorded, comprising at least 90 species of which 84% were restricted to the forest and 16% to sugarcane plantations. Other examples are numbers calculated per m2 from samples (litter and topsoil): grasslands with about 1 500 individuals and up to 20 species, coastal scrub vegetation with about 20 000 individuals and up to 40 species, coastal forests with about 46 000 individuals and up to 50 species, and savanna from the Indian Ocean Coastal Belt with about 100 000 individuals and up to 140 species per m2 (own data, unpublished). Soil mites are mostly particle-feeding saprophages and mycophages (Norton & Behan- Pelletier 2009) and play an important role in decomposition of organic material, soil fertility, nutrient cycling and soil formation (Behan-Pelletier 1993; González & Seastedt 2001; Schneider & Maraun 2005; Seastedt 1984). Early acarologists made important contributions to the study of Oribatida, sometimes under difficult conditions and with primitive equipment. One of the first major contributors was Carl Ludwig Koch (1778–1857) who lived and worked in Germany (Alberti 2004). He described many oribatid species, but mistakenly based some species and even genera on juveniles of other species or genera (Norton & Ermilov 2014). The Swiss-born Hercule Nicolet (1801– 1872) was a talented lithographer and naturalist who worked in France (Cuevas 2006). He noticed these oversights of Koch, and also studied the development and morphological transformation of mites (Norton & Ermilov 2014). The British lawyer Albert Davidson Michael (1836–1927) retired at the age of 50 to devote himself to acarology and microscopy. He was ______________________ L. Coetzee