1119-1104 Abundance and Distribution of Adult and Juvenile Stages Of

African Journal of Natural Sciences 2014, 17, 37 - 47 Njila et. al.: Abundance and distribution of adult and juvenile stages of soil microarthropods along the Western bank

ISSN: 1119-1104 ABUNDANCE AND DISTRIBUTION OF ADULT AND JUVENILE STAGES OF SOIL MICROARTHROPODS ALONG THE WESTERN BANK OF RIVER BENUE IN ADAMAWA STATE NORTH-EASTERN NIGERIA 1*Njila, H. L, 2Mwansat, G. S, 3Imandeh, G. N. and 1Onyimba, I. A. 1Department of Science Laboratory Technology and 2Department of Zoology, University of Jos, P. M. B. 2084 Jos, Nigeria 3Department of Biological Sciences, University of Agriculture, Makurdi, Benue State, Nigeria Email: [email protected]; [email protected]

(Received January 2014; Accepted August 2014) ABSTRACT Adult and Juvenile stages of microarthropods are important pests of agricultural crops. Thus, this study was aimed at investigating their abundance and distribution in relation to habitat integrity and season along the bank of River Benue in Adamawa State, North-eastern Nigeria. Soil was collected from eighteen villages situated along the river bank between 2008- 2010. Samples were taken from 0-10cm soil depth from three habitat types using a soil corer of diameter 8.5cm. The dry behavioural extraction method using Berlese-Tullgren funnel extractor was used to extract microarthropods from soil and litters. A total of 7,632 microarthropod individuals distributed in 4 classes, 20 orders, 63 families, 70 genera and 26 species were extracted from 540 soil samples. Habitat type had a significant effect (Kruskall- wallis test, df = 2, χ2 = 10.40, P = 0.001) on mean abundance of adult and juvenile stages of microarthropods. The Abundance of adults and juveniles were significantly lower with increasing habitat disturbances, thereby confirming the negative effect of the several anthropogenic activities along the western bank on natural selection. There was also a significant difference (One-way ANOVA for dry season: F1,16 = 17.14, P = 0.05; One-way ANOVA for wet season: F1,17 = 19.42, P = 0.05) in the abundance of adult and juvenile stages of microarthropods during the dry and wet seasons. The highest abundance observed only in the natural uncultivated soil underscores the importance of the western bank of river Benue in Adamawa state for conservation and calls for better protection and management. INTRODUCTION soil inhabiting arthropods in various ways, Microarthropods are an integral part to a the degreee of change on the ecology of the functioning ecosystem and perform such numerous arthropod species in the soil has roles as detritivores, herbivores, prey and hardly been measured ( David and William, predators (Cole et al., 2006 and Njila et al., 2005). The aim of this research work is to 2013). Soil microarthropods aid in establish the seasonal abundance and regulating the rates of nutrient cycling, distribution of adult and juvenile stages of decomposition and energy flow (Stephen et soil microarthropods, in relation to habitat al., 2006). Their disturbance, therefore, can and season along the western bank of River alter or disrupt these essential ecosystem Benue in Adamawa State, North-Eastern processes (Adejuyigbe et al., 2009; Nigeria. Gbarakoro et al., 2010). Even though anthropogenic activities such as agro-horti- silvicultural practices are known to affect

African Journal of Natural Sciences 2014, 17, 37 - 47 Njila et. al.: Abundance and distribution of adult and juvenile stages of soil microarthropods along the Western bank

MATERIALS AND METHODS Demsa, L.G.As which lie between Latitude Study Area 9029'53.67'' and 9°30'53.80''N and Longitude River Benue is a major river in Adamawa 12051'48.69'' and 12°58'87.52''E (Jen, 2004). State flows from the highlands of Cameroun Villages situated by the river bank in each southward through Lamurde, Numan, L.G.A. were used as sampling sites (Figure Demsa, Fufore and Yola Local Government 1). The criterion for choosing a village was Areas (L.G.A.) of Adamawa state to based on anthropogenic disturbances such as confluence with River Niger at Lokoja, after intensive agricultural activities, grazing and passing through Taraba and Benue states. burning of vegetation. A total of eighteen The study covered only Lamurde, Numan, villages were selected.

Figure 1: Map of the Sampling Sites (Source: Nigeria SatX National Remote Sensing, Jos)

Collection of Soil Samples collecting samples from dry portions of the Soil samples were collected from 0-10cm river bed (after the water has receded) soil depth for two seasons between 2008- precisely 50 meters away from the 2010 from natural soil (This involved riverbank-It was not surveyed during the wet collecting soil samples from natural and season) using a soil corer of mouth diameter uncultivated soil), cultivated soil (This 8.5cm. All soil samples collected were involved collecting samples from cultivated bagged in polythene bags, labeled according areas) and free river bottom (This involved to locations and conveyed to the laboratory

African Journal of Natural Sciences 2014, 17, 37 - 47 Njila et. al.: Abundance and distribution of adult and juvenile stages of soil microarthropods along the Western bank for extraction, identification, quantification 0.02% Smaris species, 0.02% Rabidosa and classification of arthropods. rabida, 0.02%, Nicoletia species, 0.02% Coccinella septempunctata and 0.02% Extraction Procedure Geophilus flavus as species with the least In the laboratory, the Dry Behavioural abundance of adult stages (Table 1). Extraction Method using Berlese-Tullgren Similarly, the checklist of juvenile stages Funnel Extractor (Crossely and Lair, 2001) revealed 12.87% Alaus species, 11.87% was used to extract the microarthropods Paederus species and 5.86% Phlebotomus from soil samples. After full extraction, species as species with the highest which lasted for 72 hours, the abundance of juvenile stages (Table 2). microarthropods collected were sorted, Species with the least abundance of juvenile identified and counted under Dissecting stages were Tetranychus urticae (0.05%), microscope (WILD-MSA WEERBRUGG). Allotrochosina species (0.05%), and They were identified, grouped and classified Urothrips species (0.05%). 35 adults were into orders, families, genus and species identified only to the Family level (Table 1), levels using colored atlas and identification while 281 juvenile individuals majority of keys provided by Evans et al. (1967), which were members of the Family Gizimek (1972), Castner (2000), Norton Curculionidae could not be identified beyond (2000) and Wolley (2000). the family level (Table 2).

There is a significant difference (Kruskall- Statistical Analysis 2 Microsoft excel, Statistical Package for wallis test, df = 2, χ = 10.40, P = 0.001) in Social Sciences (SPSS) 2001 506 /id the seasonal abundance of adult and juvenile software and R-console software (version 2. stages in the three habitat types studied as 9. 2) were used for data analyses. The data showed in Figures 2 and 3. Natural was tested with One-sample Kolmogorov- uncultivated soil recorded the highest Smirnov test (Wilkinson, 1990) and the abundance of both adult and juvenile stages Levenne’s test for equality of variances to of microarthropods during the two seasons, satisfy the assumption of test model (Fowler while the free river bottom had the least and Cohen, 1995). Kruskal- Wallis test was abundance in the dry season. There was no used to test Adult and Juvenile abundance free river bottom sample during the wet between the three habitat types. One way season. ANOVA was used to test Adult and Juvenile There is a significant difference (One-way abundance in the dry and wet seasons ANOVA: F , =20.36, P=0.05) in the respectively 1 16 abundance of both adult stages between seasons as shown in Figure 4. The same RESULTS trend was observed in juvenile abundance, A total of 7,632 microarthropods were also shown in Figure 4 (One-way ANOVA: extracted, out of which 5,703 (74.72%) were F , =18.42, P=0.05). Comparison of mean adults (Table 1) and 1,929 (25.28%) were 1 17 abundance of adult and juvenile stages of juveniles (Table 2). The checklist of adult microarthropods within seasons showed stages depicted 20.55% Eremulus species; significant differences (One-way ANOVA 18.50% Messor species and 7.22% for dry season: F , =17.14, P= 0.05; One- Entomobrya confuse as species with the 1 16 way ANOVA for wet season: F , =19.42, highest abundance of adult stages, while 1 17 P=0.05) as shown in Figure 4.

African Journal of Natural Sciences 2014, 17, 37 - 47 Njila et. al.: Abundance and distribution of adult and juvenile stages of soil microarthropods along the Western bank

Table 1: Checklist of Adult Stages of Soil Microarthropod Biodiversity along the Western Bank of River Benue in Adamawa State North- East Nigeria

Order Family Species NS CS FRB Total (%) Acarina Oribatidae Eremulus spp 646 525 1 1172 20.55 Nothrus spp 261 - - 261 4.58 Carabodidae Carabodes spp 17 3 - 20 0.35 Damaeidae Epidamaeus spp 31 21 - 52 0.91 Epilohmannidae Epilohmannia spp 109 46 - 155 2.72 Acaridae Acarus siro 2 142 - 164 2.88 Acarus rhombeus 284 - - 284 4.98 Tetranychidae Tetranychus urticae 32 9 - 41 0.72 Gamasidae Pergamasus crassipes 15 8 - 23 0.40 Smaridiidae Fessonia papillosa 1 - 3 4 0.07 Smaris spp 1 - - 1 0.02 Mesostigmata Trombidiidae Dinothrombium spp 60 39 144 243 4.26 Sarcoptidae Sarcoptes spp 2 5 51 58 1.02 Araneae Thomsidae Sidymella spp 13 4 - 17 0.30 Lycosidae Allotrochosina spp 4 3 - 7 0.12 Rabidosa rabida - - 1 1 0.02 Collembola Entomobryidae Entomobrya spp 64 - 77 141 2.47 Entomobrya confuse 223 126 63 412 7.22 Entomobrya albocincta 89 3 17 109 1.91 Poduridae Podura spp 242 95 - 337 5.91 Podura aquatica - 11 46 57 0.10 Isotomidae Isotomurus palustris 63 10 48 121 2.12 Isotoma spp 32 49 - 81 1.42 Folsomia spp 78 45 - 123 2.16 Diplura Campodeidae Campodea spp 13 3 26 42 0.74 Japygidae Heterojapyx evansi 29 7 - 36 0.63 Symphlurius spp - - 25 25 0.44 Thysanura Nicoletiidae Nicoletia spp 1 - - 1 0.02 Grassiella wheeleri 2 5 - 7 0.12 Protura Acerentomidae Acerentulus danicus 1 - 5 6 0.11 Acerentomon spp - - 7 7 0.12 Coleoptera Staphylinidae Paederus spp 14 6 23 43 0.75 Curculionidae * 5 18 - 23 0.40 Pselaphidae Pselaphus spp 6 7 17 30 0.53 Coccinellidae Coccinella trifasciata 2 - - 2 0.03 Carabidae Carabus spp 13 11 - 24 0.42 Bostrichidae * - 4 - 4 0.07 Tenebrionidae Gonocephalum spp 3 8 - 11 0.19 Diptera Phlebotomidae Phlebotomus spp 6 - - 6 0.11 Ceratopogonidae Culiocides spp 3 1 - 4 0.07 Trypetidae * 1 - - 1 0.02 NS = Natural Soil CS = Cultivated Soil FRB = Free River Bottom * = Microarthropod Genus/Species Unidentified

African Journal of Natural Sciences 2014, 17, 37 - 47 Njila et. al.: Abundance and distribution of adult and juvenile stages of soil microarthropods along the Western bank

Table 1 Cont.: Checklist of Adult Stages of Soil Microarthropod Biodiversity along the Western Bank of River Benue in Adamawa State North- East Nigeria Order Family Species NS CS FRB Total (%) Hymenoptera Formicidae Messor spp 673 382 - 1055 18.50 Sphecidae Sceliphoron curvatum 19 7 - 16 0.34 Chalcidae * 15 7 - 22 0.29 Aphididae Aphis sacchari 9 90 - 99 1.30 Schizaphis spp 136 12 - 148 2.60 Cicadellidae Cicadulina mbila 3 - - 3 0.05 Thysanoptera Thripidae Kakothrips spp 65 30 - 95 1.67 Isoptera Termitidae Macrotermes spp 70 19 - 89 1.56 Microtermes spp - 3 - 3 0.05 Dermaptera Forficulidae Corixa punctata 1 - - 1 0.02 Chilopoda Geophilidae Zelanion spp 2 - - 2 0.03 Geophilus flavus - 1 - 1 0.02 Isopoda Oniscoidae Oniscus asellus 1 - 1 2 0.03 Total 3363 1785 555 5703 Percent 58.97 31.30 9.73 100 NS = Natural Soil CS = Cultivated Soil FRB = Free River Bottom * = Microarthropod Genus/Species Unidentified

Figure 2: Mean Seasonal Abundance of Adult Stage of Microarthropods with Respect to Habitat Type along the Western Bank of River Benue in Adamawa State North-East Nigeria

African Journal of Natural Sciences 2014, 17, 37 - 47 Njila et. al.: Abundance and distribution of adult and juvenile stages of soil microarthropods along the Western bank

Table 2: Checklist of Juvenile Stages of Soil Microarthropod Biodiversity along the Western Bank of River Benue in Adamawa State North- East Nigeria

Order Family Species NS CS FRB Total (%) Acarina Oribatidae Eremulus spp 91 57 - 112 5.81 Carabodidae Carabodes spp 24 6 - 30 1.56 Damaeidae Epidamaeus spp 22 8 - 30 1.56 Epilohmannidae Epilohmannia spp 64 24 - 88 4.56 Tetranychidae Tetranychus urticae - 1 - 1 0.05 Gamasidae Pergamasus crassipes 8 10 - 18 0.93 Mesostigmata Sarcoptidae Sarcoptes spp - - 2 2 0.10 Araneae Lycosidae Allotrochosina spp 1 - - 1 0.05 Thysanura Nicoletiidae Nicoletia spp - - 2 2 0.10 Coleoptera Staphylinidae Paederus spp 76 141 12 229 11.87 Elateridae Alaus spp 79 167 - 246 12.87 Curculionidae * 65 272 - 337 17.47 Pselaphidae Pselaphus spp 30 11 12 53 2.75 Coccinellidae Coccinella trifasciata 24 10 - 34 1.76 Coccinella - 5 - 5 0.26 septempunctata Epilachna spp 2 - 1 3 0.16 Chrysomelidae Athous rhombeus 11 12 - 23 1.19 Donacia spp 16 10 - 26 1.35 Scarabaeidae Scarabaeus spp 6 3 - 9 0.47 Geotrupidae Geotrupes spp 13 9 - 22 1.14 Cupididae * 3 1 - 4 0.21 Meloidae Epicauta spp 1 4 - 5 0.26 Bostrichidae * 3 8 - 11 0.57 Ostomatidae * - 10 - 10 0.52 Tenebrionidae Gonocephalum spp 5 3 - 8 0.41 Diptera Phlebotomidae Phlebotomus spp 94 19 - 113 5.86 Ptychopteridae Ptychoptera 4 - - 4 0.21 contaminate Ceratopogonidae Culiocides spp 22 3 - 25 1.30 Scatopsidae Scatopse notata 6 5 - 11 0.57 Psychodidae Psychoda spp 71 16 - 87 4.51 Calliphoridae Calliphora spp 34 9 - 43 2.23 Tipulidae Tipula paludosa 15 8 - 23 0.19 Drosophylidae * 35 5 - 40 2.07 Chironomidae Chironomus spp 5 1 - 6 0.31 Opomyzidae * 3 - - 3 0.16 Trichoceridae Trichocera spp 2 - - 2 0.10 Bibionidae Dilophus spp 20 - - 20 1.04 Trypetidae * 22 2 - 24 1.24 Stratiomytidae * 3 4 - 7 0.36 NS = Natural Soil CS = Cultivated Soil FRB = Free River Bottom * = Microarthropod Genus/Species Unidentified

African Journal of Natural Sciences 2014, 17, 37 - 47 Njila et. al.: Abundance and distribution of adult and juvenile stages of soil microarthropods along the Western bank

Table 2 Cont.: Checklist of Juvenile Stages of Soil Microarthropod Biodiversity along the Western Bank of River Benue in Adamawa State North- East Nigeria

Order Family Species NS CS FRB Total Percent (%) Homoptera Aphididae Schizaphis spp 10 - - 10 0.52 Cicadellidae Cicadulina mbila 16 3 - 19 0.98 Orthoptera Gryllidae Gryllus spp 5 - - 5 0.26 Lepidoptera Saturniidae Attacus spp 23 14 - 37 1.92 Phalaenidae * 8 - - 8 0.41 Thysanoptera Thripidae Kakothrips spp 54 10 - 64 3.32 Phlaeothripidae Urothrips spp 1 - - 1 0.05 Dermaptera Forficulidae Corixa punctata 4 - - 4 0.21 Chilopoda Geophilidae Zelanion spp 5 - - 5 0.26 Geophilus flavus 5 1 - 6 0.31 Diplopoda Julidae Blanuilus guttulatus 12 5 - 17 0.88 TOTAL 1023 877 29 1929 Percent 53.03 45.46 1.50 100 NS = Natural Soil CS = Cultivated Soil FRB = Free River Bottom * = Microarthropod Genus/Species Unidentified

Figure 3: Mean Seasonal Abundance of Juvenile Stages of Microarthropods with Respect to Habitat Type along the Western Bank of River Benue in Adamawa State North-East Nigeria

African Journal of Natural Sciences 2014, 17, 37 - 47 Njila et. al.: Abundance and distribution of adult and juvenile stages of soil microarthropods along the Western bank

Figure 4: Mean Abundance of Adult and Juvenile Stages of Microarthropods with Respect to Season along the Western Bank of River Benue in Adamawa State North-East Nigeria

DISCUSSION microarthropod population can grow at geometric or exponential rates and as the Abundance of adult and juvenile stages of resources are depleted, the population microarthropods is connected to food growth rate slows and reproductive outputs availability, which may vary considerably by adults reduced, thereby affecting the between seasons and habitat types. It may be population of juvenile stages. further compounded by changing levels of inter and intra specific competition. One Ecologists have long been concerned with may therefore expect variation in the the effects of environmental factors such as abundance of juvenile and adult stages of food, shelter, rainfall, disease, floods, and microarthropods due to resource availability, role reversal of predator-prey on abundance season and habitat selection in order to of adult and juvenile stages of arthropods reduce levels of competition (Wichaikam et (Begon et al., 2003). In this study, a mixture al., 2010). of abiotic and biotic factors such as flood, habitat size, food availability and role In this study, significant differences reversal of predator-prey could have observed in the abundance of adult and contributed to the observed significant juvenile stages of microarthropods in both difference in abundance of adult and seasons is consistent with the results of juvenile stages of microarthropods in both Adejuyigbe et al. (2010) who reported seasons. This could be due to reduced differences in juvenile and adult abundance reproductive outputs by adults and high and attributed them to availability of mortality of juveniles during these periods. resource materials such as organic matter, This is consistent with the findings of Aoki macro and micro climate disposition and low et al. (2004), Benjamin et al. (2005), Saito degree of disturbance such as grazing and (2006) and Huey et al. (2012). Benjamin et fire. Seastedt and Crossley (2004) reported al. (2005) revealed that, each insect species that, in the presence of abundant resources, has certain nutritional requirements for

African Journal of Natural Sciences 2014, 17, 37 - 47 Njila et. al.: Abundance and distribution of adult and juvenile stages of soil microarthropods along the Western bank completion of its lifecycle. Under normal species and A. rhombeus in this study conditions there is a mutualistic relationship (Tables1 and 2) is associated with the between adults and juveniles. But in the diversity of their feeding habits. (Evans et event of sudden increase in population, the al., 1967; Walter and Proctor, 1999). Sequel adult population densities become too high to these diverse feeding habits therefore, to be supported by the carrying capacity in they have been considered as possible the area. Hence competition between adults biological control agents for invertebrate and juveniles for food as well as space pest species (Zhi-Qiang, 1998, Injac and resulted. He further reported that habitat size Krnjajic, 2000 and Eickwort, 2003). can strongly limit the population size of juveniles over a broad range of biotic It is worth-noting that majority of the factors, where recruitment is proportional to unidentified microarthropods were juveniles adult abundance and space. Huey et al. belonging to the Order Coleoptera and (2012) reported that temperature is the most Family Curculionidae. This is attributed to important abiotic factor which determines the extraction technique used in this study, the duration of various stages in the insect which does not permit the extraction of live life cycle and consequently the number of juvenile microarthropods that can be reared generations during any period of time. alongside the adults for easy comparison of Collaborating reports by Bale et al. (2002) morphological features. This was also on seasonal effects of weather revealed that, reported by Peckarsky (1990), that larvae of changes in climatic conditions will directly Coleoptera and Diptera exhibit considerable lead to modifications in dispersal and similarity of form, being apodous and development of insect species. Asokan et al. eucephalous and are often very difficult to (2008) affirmed that changes in surrounding identify to species level without rearing the temperature regimes will certainly involve larvae to adults. alteration in developmental rates, voltinism CONCLUSION and survival of insects and subsequently The natural uncultivated soil which enjoys affect size, density and genetic composition some level of protection was higher in adult of populations as well as host plant and juvenile abundance than the cultivated exploitation. Saito (2006) reported an soil and free river bottom. This underscores incidence of role reversals observed in the importance of the western bank of river systems that are viewed as classical Benue in Adamawa state for predator-prey systems, where adults of microarthropods conservation and calls for spider mite prey Schizotetranychus celarius better protection and management. However, attack and kill juvenile stages of their the very low juvenile’s abundance across the predator, the phytoseiid mite Typhlodromus three habitat types indicates resource bambusae. In another study Aoki et al. depletion which had effects on the juvenile (2004) observed first-instar larvae of the population growth rate and reproductive out sugar-cane woolly aphid, Ceratovacuna puts by adults. Be that as it may, many of the lanigera, attacking and piercing predator juvenile stages identified are important pests eggs of Dipha aphidivora with their horns. of agricultural crops, hence detail In some cases, adults kill the juveniles of taxonomic, life cycle and pest management other species but do not consume them, studies/ research should be mounted. suggesting that the killing serves to reduce future predation risk or competition. REFERENCES

Adejuyigbe, C.O., Tian, G. and Adeoye, Higher species abundance of adult stages of G.O. (2009). Soil microarthropods Messor species, Eremulus species, E. Populations under natural and confuse, Dinothrombium species, Podura planted flowers in South Western

African Journal of Natural Sciences 2014, 17, 37 - 47 Njila et. al.: Abundance and distribution of adult and juvenile stages of soil microarthropods along the Western bank

Nigeria. AgroForestry System 4: study. Applied Soil Ecology 33: 186- 263-272. 198.

Aoki, S., Kurosu, U. and Usuba, S. Crossley, D.A. and Lair, J.M. (2001). A (2004). First instar larvae of the high efficiency “Low-Technology” sugar-cane wooly aphid, Tullgren Type extractor for soil Ceratovacuna lanigera (Homotera: microarthropod. Agriculture, Pemphigidae), attack its predators. Ecosystems and Environment 34: Kontyû 52: 458–460. 187-192.

Asokan, S., Ali, A.M.S., Manikannan, David, C.C. and William, B.W. (2005). K and Radhakrishnan, P. (2008). Linking species richness, Studies of insect composition in the biodiversity and ecosystem function common Myna Acridotheres tristis in soil systems. Pedobiologia 49: L. Trend in Karis Research 3 (1): 479-497. 72-79. Eickwort, G.C. (2003). Potential use of Bale, J., Masters, G., Hodkinson, I., mites as biological control agents of Awmack, C., Jnbezemer, T.M., leaf-feeding Insects. In Biological Brown, V.K.,Butterfield, J., Buse, control of pests by mites, H.A. Hoy, A., Coulson, J.C., Farrar, J., Good, G.L. Cunningham and L. Knutson J.G. and Harrington, R. (2002). (eds.),University of California Herbivory in global climate change Press/ANR Publishing Co, Oakland.pp. research: direct effects of rising 460-474. temperature on insect herbivores. Journal of Global change Biology 8: Evans, G.O., Sheals, J.G. and 1-16. Macfarlane, D. (1967). The Terrestrial Acari of the British Isles: Begon, M., Harper, J.L and Townsend, An introduction to their morphology C.R. (2003) Ecology of individuals, and classification. Doking Adlard th populations and communities. (4 and Son, Bartholomew, vol.1. edition) Blackwell Science Ltd. Pp. 654pp. 884-912. . Fowler, J. and Cohen, L. (1995). Statistics for Benjamin S. H., Steven D. G. and Ornithologists. Second Edition. BTO Guide Robert R. W. (2005). Habitat Size, No 22, pp. 98-103. Recruitment, and Longevity as Factors Limiting Population Size in Gbarakoro, T.N., Okiwelu, S.N., Stage-Structured. American Badejo, M.A. and Umeozor, O.C. Naturalist 165 (1): 82–94. (2010). Soil microarthropods in a secondary rainforest in Rivers State, Castner, J.L. (2000) Photographic Atlas Nigeria: Seasonal variations in of Entomology and Guide to insect species richness, vertical distribution Identification, Feline Press anddensity in an undisturbed habitat. Gainesville U.S.A. Inc. Pp.74-223. Scientia Africana 9 (1): 46-54.

Cole, L.J., Bradford, M.A., Shaw, P.J.A. Gizimek, B. (1972). Grzimek Animal and Bardgett, R.D. (2006). The Life Encyclopedia.Van nostrand abundance richness and functional Reinhold Company, New York, role of soil microarthropod. A case pp.19-177.

African Journal of Natural Sciences 2014, 17, 37 - 47 Njila et. al.: Abundance and distribution of adult and juvenile stages of soil microarthropods along the Western bank

Saito, Y. (2006). Prey kills predator: counter Huey, R.B., Kearney, M.R., attack success of a spider mite against its Krockenberger, A., Holtum, J.A.M., specific phytoseiid predator. Jess, M. and Williams, S.E. (2012). Experimental and Applied Acarology 2: Predicting organismal vulnerability 47–62 to climate warming: roles of behaviour, physiology and Seastedt, T.R. and Crossley, D.A. (2004). adaptation. Philosophical The influence of arthropods on Transactions of the Royal Society of ecosystems. Bioscience 34: 157-161. London 67: 1665-1679. Stephen, P., Alexandra, M. and Stefan, Injac, M. and Krnjajic, S. (2000). The S. (2006). Decomposers role of natural enemies in reduction (Lumbricidae: Collembola) affect of the Mamestra brassicae L. plant performance in model population density in the region of Grasslands of different Diversity. Belgrade. Zastita Bilia 41: 111–124. Ecology 87 (10): 25-48.

Jen, S.U. (2004). Fundamentals of Walter, D.E. and Proctor, H.C. (1999). research methodology 3rd Edition. Mites: Ecology, Evolution and Department of Geography, Federal Behaviour. University of New South University of Technology Yola Wales press and CAB international Adamawa State, Nigeria. 104pp. Publishing Wallingford, 332pp.

Mira, L., Heikki, S., Hari, H., Taina, P. Wichaikam, N., Anusontpornperm, S., and Hannu, F. (2002). Relationship Sakchoowong, W. and Amornsak, between soil Microarthropod species W. (2010). Seasonal and Habitat- diversity and plant growth does not Specific Differences in Soil Insect change when the system is disturbed. Abundance from Organic Crops and Oikos 96 (1): 137-149. Natural Forest at the Ang Khang Royal Agricultural Station, Chiang Njila, H.L, Mwansat, G.S. and Imandeh, Mai, Thailand. Thai Journal of G.N. (2013). Species abundance and Agricultural Science 43 (4): 231- diversity of soil mites (Arachnida: 237. Acari) along the bank of River Benue in Adamawa State, north-eastern Nigeria. Wilkinson, L. (1990). The system for Biological and Environmental Sciences statistics. Systat inc. Evanston Journal for the Tropics 10(4): 37-44. Illinois, 275pp.

Norton, R.A. (2000) Acarina: Oribatida Wolley, T.A. (2000). Acarology: Mites In: Dindal D. L., (ed). Soil Biology and human welfare. John Wiley, Guide, New York: Journal of Wiley New York: 19(9): pp. 461-463. 19(9): 779-803. Zhi-Qiang, Z. (1998). Biology and Peckarsky, B.L. (1990). Fresh water Ecology of Trombidiid mites (Acari: macroinvertebrates of North Trombidiodea). Experimental and American. Aquatic Entomology 4: Applied Acarology 22: 139-155 17-18.