19-23 19 S. H. Mahmood Bull. Iraq nat. Hist. Mus. (2003) 10 (1): 19-23 NEW RECORDS OF SOME MITE SPECIES INHABITING SOIL IN BAGHDAD Souhaila H. Mahmood Iraq Natural History Museum, University of Baghdad, Bab Al-Muadham, Baghdad, Iraq ABSTRACT The soil acari fauna of Citrus orchards of Baghdad in Jadiriya area was studied in a total of forty-eight samples. Twenty-two species were recorded during the present study of which eight species were first records to Iraq. The ordinal composition of the soil acari fauna was predominantly Mesostigmata. This fauna represents diverse trophic groups. The most abundant groups were the predacious and the Microphytophagus, while the less abundant groups were the predacious/ Microphytophagus, Macrophytophagus, and Panaphytophagus. The most abundant and frequent species were Rhizoglyphus sp. Tyrophagus putrescentiea (Scrank), Pachylaelaps longisetis Halbt. and Stratiolaelaps miles Berl. INTRODUCTION It is well known that the soil arthtropoda play an assential part in the biological fertility of soil. Their activity contributes greatly to organic decomposition, the synthesis of humus, the restitution of biogenic element and the stimulation of fungal and bacterial metabolism, the mesofauna which includes subclass acari are involved both directly (Berthet, 1963 and Macfadyen, 1964) and indirectly (Witkamp, 1960) in this process. The acari fauna of soil has been studied extensively by many workers among them (Ford, 1935;Wies-Fogh, 1948; Sheals, 1957; Block, 1965; Wood, 1967; Longworth, 1977; Curry, 1979; and Luxton, 1983). Investigation on soil acari fauna in Iraq is scarce. The only work on this fauna that which reported by Mursi et al. (1966) from Palms-Citrus orchards and the checklist by Abul-hab (1984). The main objective of this study is to investigate the soil acari fauna in Baghdad providing more information regarding the checklist of this fauna. MATERIALS AND METHODS A total of 48 samples were collected from the soil of Citrus orchards, in Baghdad (Jadiriya) over a period of six months from October 1992 to March 1993. All the samples were taken from the top of 10 cm by a steel Core-Sampler with case hardened cutting edge (Macfadeyn, 1961). It consisted of a 6.3 cm diameter cylinder narrowing to 5.8 cm at the cutting edge, to avoid compression of soil sample. These samples were individually extracted in the laboratory through a modified Tullgren funnels extractor. The extracted mites were cleared by heating in 50% Lactic acid then mounted in Hoyer’s medium on glass slides, and examined under a phase-contrast microscope. The analysis of soil where the samples were taken showed that it was silty-loam with a relatively high organic matter about 2.2 percentage. 20 New records of mites Tale 1: A systematic list of identified mites with their dominancy and frequency of occurrence in soil of Citrus orchards. * Species and genera were first records to Iraqi fauna. Species Occurrence % Frequency Dominancy ORDER ASTIGMATA Family Acaridae Acarrus sire L. 4.2 1.3 Caloglyphus berlesi (Michael) 8.6 3.1 Rhizoglyphus sp. 33.3 17.7 Tyrophagus sp. 8.5 3.1 Tyrophagus putrescentiae (Schrank) 14.0 10.9 ORDER CRYPTOSTIGMATA Family Ceratozetidae *Ceratozetes gracilis (Michael) 2.1 0.8 Family Hypochthoniidae *Hypochthonius sp. 2.1 0.1 Family Malaconthriidae *Malaconthrius sp. 12.5 2.7 Family Oribatulidae Oribatula sp. 4.2 2.1 Family Stenoobelbidae *Stenobelba sp. 4.5 2.1 ORDER MESOSTIGMATA Family Laelapidae *Hypoaspis lubrica Voigts & Oudms. 8.6 7.3 *Stratiolaelaps miles (Berl.) 14.2 10.9 Family Macrochelidae *Geholaspis nr. longispinosus (Kr.) 2.1 0.6 Family Pachylaelapidae *Pachylaelaps longisetis Halbt. 45.8 20.7 Family Parasitidae *Holoparasitus pallicipatus (Berl.) 4.2 2.3 *Paragamasus crassipes (Linn.) 2.1 2.4 Family Uropodidae *Trematura jacksoni Hughes 2.1 1.2 Urobovella marginata (C. L. K.) 8.5 6.4 ORDER PROSTIGMATA Family Bdellidae Bdella sp. 2.1 0.2 Family Camerobiidae Camerobia sp. 2.1 0.2 Bakerdinia 4.2 3.1 Family Tydidae *Triphtydeus 2.1 0.8 21 S. H. Mahmood RESULTS AND DISCUSSION Twenty-two species of mites were recorded during the present work. Of these 8 species and 4 genera were new records to Iraqi fauna, while the remaining species were previously reported from Iraq (Mursi et al., 1966; Abul-hab, 1984; Mahmood, 1987; and Mahmood and AlDulaimi, 1988). The identified species were classified into different orders, 8 of the recorded species were of the order Mesostigmata, 5 species of each of Astigmata and Cryptostigmata, and the last four species were of Prostigmata (Table 1). The dominancy and frequency of occurrence of these species varied from one species to another, the most common and abundant species were Rhizoglyphus sp., Tyrophagus putrescantiea (Scrank), Pachylaelaps longisetis Halbt., Stratiolaelaps miles Berl. The species occurred in 33.3%, 14%, 45.8%, 14.2% and 8.5% of the total samples respectively. It is recognized from the present results that the acari fauna of soil represents diverse trophic groups (Table 2). The classification of each species into their trophic groups was made by reference to the literature (Krantz, 1978 and Luxton, 1982). Table 2: The percentage contribution of trophic groups to the total acarina fauna in the soil of Citrus orchards with the number of species represented by each group. Trophic group % of abundance Number of species Predacious 50.8 8 Microphytophagus 44.9 10 Predacious/Microphytophagus 2.8 2 Panaphytophagus 0.2 1 Macrophytophagus 1.3 1 The most abundant group was Predacious, which occurred in 50.8% of the total acari and represented by 8 species. The second most abundant group was the Microphytophagus, which occurred in 44.9% and represented by 10 species. The less abundant groups were the predacious/Microphytophagus, which represented by three species, Macrophytophagus and Panaphytophagus, each of them represented by one species only. These results could be a reflect of well developed microflora associated with abundant supply of decaying organic matter (animal manure was added regularly to the orchard’s soil) and also to the presence of a wide range of preys in the soil particularly Collembola and nematodes, since it were observed in the examined samples in a respectable numbers. Similar phenomenon was reported by Mursi et al. (1966) from palm-Citrus orchards and Luxton (1982) from grassland. The most interesting aspect of this work is the presence of many important predacious mites such as P. longisetis, S. miles, H. lubrica and U. marginata in a relatively high numbers. This may have important indirect effects on decomposition process and mineral cycling through their interaction and through litter combination (Witkamp, 1971 and Luxton, 1972). LITERATURE CITED Berthet, B. 1967 The metabolic activity of oribatid mites Acarina in different forest floors in secondary productivity of Terrestrial Ecosystems. Ed. K. Petruse Wtz. Warsaw: pp. 709-725. Block, W. C. 1965 Distribution of soil mites Acarina on the Moor House National Nature Reserve, Westmoreland, with notes on their numerical abundance. Pedobiologia, 5: 244-251. 22 New records of mites Curry, J. P. 1979 The arthropod fauna associated with cattle manure applied as slurry to grassland. Proc. R. Irish. Acad. Section B,79. Ford, J. 1935 The animal populations of a meadow near Oxford. J. Anim. Ecol., 4:195-207. Jalil Abu-hab 1984 Further contribution to the acarina fauna of Iraq. Internat. J. Acarol., 10(1):43-44. Krantz, G. W. 1978 A manual of Acarology. 2nd edition. Oregon State University Book Stores, Inc., Corvallis, Oregon. Longworth, T. J. 1974 Some aspects of the ecology of the acari of virgin and reclained blanket big at glanamoy, Co. Mayo. Ph. D. thesis, National University of Ireland. Luxton, M. 1972 Studies on the oribatid mites of a Dunish beech wood soil. Pedobiologia,12: 434-463. Luxton, M. 1982 Studies on the invertebrate fauna of New Zealand peat soils. IV. Pedobiologia, 24: 297-308. Luxton, M. 1983 Studies on the invertebrate fauna of New Zealand peat soils. V. Pedobiologia, 25: 135-148. Macfadeyn, A. 1961 Improved funnel-type extraction for soil arthropods. J. Anim. Ecol., 30: 171-182. Macfadeyn, A. 1964 Realations between mites and microorganisms and their significance in soil biology. Proc. 1st Int. Cong. Acar., 147. Mahmood, S. 1987 Mites associated with stored grain in Baghdad. J. Biol. Sci. Res., 18: 2 Mahmood, S. and Al-Dulaimi, S. I. 1988 Ecological study of new records of Iraqi predator mites developing in animal manure. J. Biol. Sci. Res., 19:865-876. Mursi, A. A., Hussain, A. A. and Kassim, B. M. 1966 Soil insects and mites of palm orchards in Iraq. Bull. Soc. Ent. Egypt, L:71-78. Wies-Fogh, T. 1948 Ecological investigations on mites and collembola in the soil. Nat. Jutland., 1: 135-270. Witkamp, M. 1971 Soils as components of ecosystems. A Rev. Ecol. , Sist., 2: 85-100. Wood, T. G. 1967 Acari and collembola of moorland soils from Yorkshire, England. Vertical distribution in four grassland soils. Oikes, 18: 137-140. 23 S. H. Mahmood Bull. Iraq nat. Hist. Mus. (2003) 10 (1): 19-23 د غدا ة ف ب رب ق ن ال ي ت حلم ا ت ع ا ض ان ا دة لب ج ي ال جي س ت مود ح وي م حيا سهيلة ي ع خ ال بي ري ف ال ا ح داد -مت ة بغ م -جامع ظ ب ال ع د - با غدا ق –ب العرا ة ص الخال يف غداد ت ض ا حلم ب ا م اليت صي حلل ت م عة ا رس ل د ال ن خ جلادرية وذجاً ٤٨منط ة . ت جل د ٢٢س ل ال عً خ و قن يف ا عرا ل رة الو ل ج س وا ت سة ا ا ية نها مثاني ان .را ت رتبة .هي الشائعة بني اموعات التقسيم حللم الرتبة Mesostigmataكان و Predaciousمتثـــــــــــــل هـــــــــــــذه اموعـــــــــــــةجماميع غذائيـــــــــــــة واســـــــــــــعة، كانـــــــــــــت اـــــــــــــاميع Microphytophayus االوسع انشاراً بينما كانت ااميعPanaphytophagus و Macrophytophagus Rhizoglyphus Tyrophagus putrescentiea, Pachylaelaps longisetis Stratiolaelaps miles .