Nevertheless, the rates of disappearance revealed suggest that underground predation is likely to be an important parameter in insect population dynamics, and so of concern to pest managers. It is therefore of interest to note the impact of pesticides on soil predation. In the studies on both overground and soil insecticides, pupal disappearance and predator contact with prey were reduced immediately after application, but the effects proved short-lasting, and relatively unimportant at depth.
However, it must be remembered that an important element in the effects that any insecticide have on natural communities is the area treated. Mobile animals quickly reinvade insecticide-treated areas, once the effects of the insecticide wear off, as they do rapidly with modern low persistence chemicals (Murdoch, et al. 1985; Murdoch & Oatens, 1988 and Judd & Mason, 1995). In the present experiments, the areas treated were only one square meter each. It is also difficult to disentangle the effects that low doses of insecticides have on mortality, compared with repellency. The latter only protects prey and predators if, as in this case, there is a small scale mosaic of treated and untreated areas, but the present study is interesting in its implications that treatment might (presumably through repellency) drive predators deeper into the soil. The effects observed are generally similar both with an insecticide which is likely to reach the soil only as run-off from crop spraying (permethrin) and with a more specifically designed insecticide for soil pests (dursban). An interesting extension of this would be to compare insecticide formulations such as granules, which are now commonly used for soil applications.
However, the results in general confirm the view that the soil is a robust ecological system, rather resilient to pesticide damage with its highly active microbial flora which can break down a wide range of chemicals, and its finely divided mineral and organic content which can adsorb both the pesticides and their breakdown products. It is for these reasons that soil animals are so difficult to control chemically, and why perhaps soil predators can also recover rapidly.
A study such as this usually raises more questions than it solves, and the reasons why some groups such as Diplura should show a strong preference for nocturnal activity, when they operate deep within the soil is unknown. However, it is hoped that the present study has shown that the use of rhizotrons can illuminate an important, and much neglected area of ecology, namely the activity and population dynamics of soil organisms.
Reference
Armstrong, G. 1995. Carabid beetle (Coleoptera, Carabidae) diversity and abundance in organic potatoes and conventionally grown seed potatoes in the north of Scotland. Pedobiologia 39: 231-237.
Asteraki, E.J. 1993. The potential of carabid beetles to control slugs in grass clover swards. Entomophaga 38: 193-198.
Asteraki, E.J., Hanks C.B. and Clements, R.O. 1992. The impact of two insecticides on predatory ground beetles (Carabidae) in newly sown grass. Annals of applied Biology 120: 25-39.
Bailey, R.R., Vandenberghe, E.P and McCarthy, B.C. 1994. New records and activity patterns of carabid beetles (Coleoptera, Carabidae) in Western Maryland. Coleopterist Bulletin 48: 319-323.
Beddington, J.R. 1975. Mutual interference between parasitoids or predators and its
effect on searching efficiency. Journal of Animal Ecology 44: 331-340.
Best, R.L. and Beegle, C.C. 1977. Food preference of Five species of carabids commonly found in Iowa cornfields. Environmental Entomology 6: 9-12.
Best, R.L., Beegle, C.C., Owents, J.C. and Oritz, M. 1981. Population density, dispersion and dispersal estimates for Scarite subriatus, Pterostichus chalchites and Harpalus pennsylvanicus (Carabidae) in lowa cornfield. Environmental Entomology 10: 847-856.
Booij, C.J.H. and Noorlander, J. 1992. Farming systems and insect predators. Agriculture Ecosystems and Environment 40: 125-135.
Brust, G.E., Stinner, B.R. and McCartney, D.A. 1985. Tillage and soil insecticide effects on predator black cutworm (Lepidoptera: Noctuidae) interactions in corn agroecosystems. Journal of Economic Entomology 78: 1389-1392.
Brust, G.E., Stinner, B.R. and Mc.Cartney, D.A. 1986. Predation by soil inhabiting arthropods in intercropped and monoculture agroecosystems. Agriculture Ecosystems & Environment 18: 145-154.
Carcamo, H.A. and Spence, J.R. 1994. Crop type effects on the activity and distribution of ground beetles (Coleoptera, Carabidae). Environmental Entomology 23: 684-692.
Cardwell, C., Hassall, M. and White, P. 1994. Effects of headland management on carabid beetle communities in Breckland cereal fields. Pedobiologia 38: 50-62.
Cappaert, D.L., Drummond, F.A. and Logan, P.A. 1991. Incidence of natural enemies of the colorado potato beetle, Leptinotarsa decemlineata (Coleoptera, Chrysomelidae) on a native host in Mexico. Entomophaga 36: 369-378.
Carpenter, A., Cherrett, J.M., Ford, J.B., Thomas, M. and Evans, E. 1985. An inexpensive rhizotron for research on soil and litter living organisms. Ecological interactions in soil. Eds. A.H. Fitter, D. Atkinson, D.J. Read, and M.B. Usher. Blackwell Sci. Publ. Oxford.
Chaabane, K., Josens, G. and Loreau, M. 1993. Quantitave assessment of consumption by Abax ater Villers (Coleoptera, Carabidae). Pedobiologia 37: 291-302.
Chiverton, P.A. 1986. Predator density manipulation and its effects on populations of Rhopalosiphum padi (Hom., Aphididae) in spring barley. Annals of applied Biology 109: 49-60.
Clark, M.S., Luna, J.M., Stone, N.D. and Youngman, R.R. 1994. Generalist predator consumption of armyworm (Lepidoptera, Noctuidae) and effect of predator removal on damage in no-till corn. Environmental Entomology 23: 617-622.
Clark, M.S., Luna, J.M. and Youngman, R.R. 1985. Estimation of adult carabid absolute densities in a no-till corn field by removal sampling. Applied Soil Ecology 2: 185-193.
Cockfield, S.D. and Potter, D.A. 1985. Predatory arthropods in high and low maintenance turfgrass. Canadian Entomology 117: 423-429.
Digweed, S.C. 1993. Selection of terrestrial gastropod prey by cychrine and Pterostichine ground beetles (Coleoptera, Carabidae). Canadian Entomology 125: 463-472.
Dixon, P.L. and McKinlay, R.G. 1992. Pitfall trap catches of and aphis predation by Pterostichus melanarius and Pterostichus madidus in insecticide treated and untreated potatoes. Entomologia Experimentalis Et Applicata 64: 63-72.
Edwards, C.A., Sunderland, K.D. and George, K.S. 1979. Studies on Polyphagous predators of cereal aphids. Journal of Applied Ecology 16: 811-823.
Edwards, C.A., Skinner, B.R., D. and Rabatin, S. (Eds) 1988. Biological interactions in soil. in Book Review of Journal of Animal Ecology 60: 1100-1101.
Ekbom, B. 1994. Arthropod predators of the pea aphid, Acyrthosiphon pisum Harr. (Hom., Aphididae) in peas (Pisum sativum L ), clover (Trifolium pratense L) and alfalfa (Medicago sativa L). Journal of Applied Entomology - Zeitschrift fur Angewandte Entomology 117: 469-474.
Endler, J.A. 1988. Frequency-dependent predation, crypsis and aposematic coloration. Phil.Trans.R.Soc.Lond. B 319: 505-523.
Fan, Y.Q., Liebman, M., Groden, E. and Alford, A.R. 1993. Abundance of carabids and other ground-dwelling arthropods in conventional versus low-input bean cropping system. Agriculture Ecosystems & Environment 43: 127-139.
Filippitsukamoto, L., Nomakuchi, S., Kuki, K. and Tojo, S. 1995. Adaptiveness of parental care in Parctstrachia japonensis (Hemiptera, Cydnidae). Annals of the Entomological Society of America 88: 374-383.
Frambs, H. 1994. The importance of habitat structure and food supply for carabid beetles (Coleoptera, Carabidae) in peat bogs. Memoirs of the Entomological Society of Canada 169: 145-159.
Godfray, H.C.J. and Pacala, S.W. 1992. Aggregation and population dynamics of parasitoids nd predators. American Naturalist 140:30-40.
Good J.A. and Giller, P.S. 1991. The effect of cereal and grass management on staphylinid (Coleoptera) assemblages in South West Ireland. Journal of Applied Ecology 28:810-826.
Gratwick, M. 1992. Crop pests in the UK. Chapman & Hall. London UK. 490p.
Greenslade, P.J.M. 1964. Pitfall trapping as a method for studying populations of Carabidae (Coleoptera). Journal of Animal Ecology 33:103-110.
Griffith, D.M. and Brown, J.S. 1992. A null model of patch assessment with an application to a carabid cave beetle. Oikos 64: 523-526.
Griffith, D. M. and Poulson, T.L. 1993. Mechanisms and consequenses of intraspesific competition in a crabid cave beetle. Ecology 74: 1373-1383.
Gunn, A. and Cherrett, J.M. 1993. The exploitation of food resources by soil meso- and macro invertebtates. Pedobiologia 37: 303-320.
Hassel, M.P. and May, R.M. 1974. Aggregationin predators and insect parasites nd its effect on stability. Journal of Animal Ecology 43: 567-594.
Hassel, M.P., Lawton, J.H. nd Beddington, J.R., 1976. The component of arthropod predation. I. The prey death-rate. Journal of Animal Ecology 45: 135-164.
Hassel, M.P., Lawton, J,H. and Beddington, J.R., 1997. Sigmoid functional response by invertebrate predators and parasitoids. Journal of Animal Ecology 46: 567-594.
Hassel, M.P., 1985. Insect Natural enemies as regulating factors. Journal of Animal Ecology 54: 323-334.
Hassel, M.P. and May, R.M. 1986. Generalist and spesialist natural enemies in insect predator-prey interactions. Journal of Animal Ecology 55: 923-940.
Hassel, M.P., 1987. Detecting regulation in patchily distributed animal populations. Journal of Animal Ecology 56: 705-713.
Head, G.C. 1973. Shedding of roots. In, Shedding of plant parts (ed, T.T.Kolowski) pp. 237-293. Accdemic Press, New York.
Heimpel, G.E. and Houghgoldstein, J.A. 1992. survey of arthropod predators of Leptinotarsa decemlineata (Say) 1 in Delaware Potato field. Journal of Agricultural Entomology 9: 137-142.
House, G.J. and All, J.N. 1981. Carabid beetles in soybean agroecosystem. Environmental Entomology 10: 194-196.
Holopainen, J.K. and Helenius, J. 1992. Gut content of ground beetles (Coleoptera, Carabidae), and activity of these and other epigeal predators during an outbreak of Rhopalosiphum padi. Acta Agricultural Scandinavica Section B-Soil nd Plnt Science 42: 57-61.
Huck, M.G. and Taylor, H.M. 1982. The rhizotron as a tool for root research. Advances in Agronomy 35: 1-35.
Hughes, L. and Westoby, M. 1992. Capitula in stick insect eggs and Elaisomes on seeds - convergent adaptations for burial by ants. Functional Ecology 6: 642-648.
Humphreys, I.C. and Mowat, D.J. 1994. Effects of some organic treatments on predators (Coleoptera, Carabidae) of cabbage root fly, Delia radicum L (Diptera, Anthomyiidae), and on alternative prey species. Pedobiologia 38: 513-518.
IPPG (Institute for plant protection Germany), 1989. Plant protection in agriculture and grassland in Braunschweig. Review of Applied Entomology 77: 6100.
Ives, A.R. and Dobson, A.P. 1987. Antipredator behaviour and the population dynamics of simple predator-prey systems. American Naturalist 130: 431-447.
Judd, K.W. and Mason, C.F. 1995. Colonisation of restored landfill site by invertebrates, with particular reference to the Coleoptera. Pedobiologia 39: 116-125.
Loreau, M. 1988. Determinants of the seasonal pattern in the niche structure of forest carabids. Pedobiologia 31, 5-87.
Loughridge, A.H. and Luff, M.L. 1983. Aphid predation by Harpalus rufipes Degeer (Coleoptera: Carabidae) in the laboratory and field. Journal of Applied Ecology 20: 451-462.
Luff, M.L. 1987. Biology of polyphagous ground beetles in Agriculture. Review of Agriculture Zoology 2: 237-278.
Luff, M.L., Eyre, M.D. and Rushton, S.P. 1989. Classification and ordination of habitats of ground beetles (Coleoptera: Carabidae) in North-East England. Journal of Biogeography 16: 121-130.
Luff, M.L. and Rushton, S.P. 1988. The effects of pasture improvement on the ground beetle and spider fauna of upland grassland. Aspects of Applied Biology 17: 67-74.
Lussenhop, J., Fogel, R., and Pregitzer, K. 1990. A new dawn for soil biology : video analysis of root-soil-microbial-faunal interactions. Agriculture Ecosystems & Environment 34: 235-249.
Lys, J.A. 1995. Observation of epigeic predators and predation on artificial prey in a cereal field. Entomologia Experimentalis et Applicata 75: 265-272.
Malcolm, S.B. 1992. Prey defence and predator foraging. In: Natural enemies. Ed Crawley M.J. Blackwell Scientific Publication. London.
McBrayer, J.F. and Reichle, D.E. 1971. Trophic structure and feeding rates of forest soil invertebrate populations. Oikos 22: 381-388.
Murdoch, W.W., Chesson, J., and Chesson, P.L. 1985. Biological control in theory and practice. American Naturalist 125: 344-366.
Murdoch, W.W. and Oatens, A.S. 1988. Aggregation by parasitoids and predators: effects on equilibrium and stability. American Naturalist 134: 288-310.
Nelemans, M.N.E. 1987. Possibilities for flight in the carabid beetle Nebria brevicolis (F). The importance of food during larval growth. Oecologia 72: 502-509.
Nelemans, M.N.E. 1988. Surface activity and growth of larvae of Nebria brevicolis (F) (Coleoptera: Carabidae). Nederlands Journal of Zoology 38: 74-95.
Newman, R.I., Ritz, K. and Jupp, A.P. 1989. The functioning of roots in the grassland ecosystem. Aspects of Applied Biology 22: 263-269.
Oksamen, T., Oksamen, L. and Fretwell, S.D. 1985. Surplus killing in the hunting strategy of small predators. American Naturalist 126: 328-346.
Riddick, E.W. and Mills, N.J. 1995. Seasonal activity of carabids (Coleoptera, Carabidae), affected by microbial and oil insecticides in an apple orchard in California. Environmental Entomology 24: 361-366.
Sackville-Hamilton, C.A.G., Cherrett, J.M., Ford, J.B., Sagar, G.R. and Whitbread, R. 1991. A modular rhizotron for studying soil organisms: Construction and establishment. In: Atkinson, D.. Robinson, D & Alexander, I.J. (Eds) Plant root growth: An Ecological Perspective. British Ecological Society Publication No.10 Blackwell Scientific Publications, Oxford. Pp 49-59.
Sims, P.L. and Singh, J.S. 1978. The structure and function of ten western North American grasslands II. Intra-seasonal dynamics in primary producer compartments. Journal of Ecology 66: 547-572.
Southwood, T.R.E. 1978. Ecological methods with particular reference to the study of insect populations. John Wiley and Sons. New York. 524p.
Spence, J.R. and Niemela, J.K. 1994. Sampling carabid assemblages with pitfall traps - The madness and the method. Canadian Entomologist 126: 881-894.
Sunderland, K.D. 1975. The diet of some predatory arthropods. Journal of Applied Ecology 12: 507-515.
Sunderland, K.D., Crook, N.E., Stacey, D.L. and Fuller, B.J. 1987. A study of feeding
by polyphagous predators on cereal aphids using ELISA and the gut dissection. Journal of Applied Ecology 24: 907-933.
Symondson, W.O.C. and Liddell, J.E. 1995. Decay-rates for slug antigens within the carabid predator Pterostichus melanarius monitored with a monoclonal-antibody. Entomologia Experimentalis et Applicata 75: 245-250.
Tolonen, T. 1995. Importance of generalist epigeal predator species in a cereal field - predation on baits. Journal of Applied Entomology 119: 113-117.
Vickerman, G.P. and Sunderland, K.P. 1980. Arthropods in cereal crops : nocturnal activity, vertical distribution and aphid predation. Journal of Applied Ecology 17: 755-766.
Wiedenmann, R.N., Larrain, P.L and Oneil R.J. 1992. Pitfall sampling of ground beetles (Coleoptera, Carabidae) in Indiana Soybean Fields. Journal of Kansas Entomological Society 65: 279-291.
Zhao, D.X., Boivin, G. and Stewart, R.K. 1990. Consumption of carrot weevil
(Coleoptera, Curculionidae) by 4 species of carabids on host plants in the
laboratory. Enthomophaga 35: 57-60.
