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Insect infestations and their effects on the growth and yield of field crops: a review

Published online by Cambridge University Press:  10 July 2009

R. Bardner
Affiliation:
Rothamsted Experimental Station, Harpenden, Hertfordshire, AL5 2JQ, England
K. E. Fletcher
Affiliation:
Rothamsted Experimental Station, Harpenden, Hertfordshire, AL5 2JQ, England

Abstract

A knowledge of the often complex relationship between insect populations and their effects on the yield-forming processes of crops is useful for assessing pest status and for devising methods of minimising the effects of infestation on yield. After a preliminary section on definition of terms, consideration is given to ways in which insects injure plants and crops, particularly annual crops. Investigations into the yield-forming processes of unattacked crops can often provide useful insights into the likely effect of insect injuries on yield. The differences between the characteristics of individuals and populations are discussed, both of insects attacking plants, and plants responding to the attacks of insects. The distribution of insects on plants and on crops and the effect that this has on damage is considered, as is the time and duration of the attack in relation to the growth cycle of the crop. The components of plant resistance to insect attack are then discussed, especially tolerance and the various ways in which plants and crops compensate for injury. The review concludes with an examination of the quantitative relationships between numbers of insects or injuries and their effects on yield. The generalised response is a sigmoid curve relating an upper and lower plateau of yield where changes in the numbers of insects or injuries have little effect. Most relationships conform to some part of this curve, though few show all its features.

Type
Review Article
Copyright
Copyright © Cambridge University Press 1974

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References

Anglade, P. (1961). Influence sur le rendement du maïs de l'infestation des tiges par la deuxième génération de la sésamie Sesamia nonagriodes Lef. (Lep. Noctuidae.) Méthodes de comparaison des hybrides par infestation artificielle.—Annls Épiphyt. 12, 357372.Google Scholar
Banks, C. J. & Macauley, E. D. M. (1967). Effects of Aphis fabae Scop. and of its attendant ants and insect predators on yields of field beans. (Vicia faba L.)Ann. appl. Biol. 60, 445453.CrossRefGoogle Scholar
Bardner, R. (1965). Losses to potatoes by aphid attack.—Rep. Rothamsted exp. Stn 1964, 179.Google Scholar
Bardner, R. (1966). Aphid damage to potatoes.—Rep. Rothamsted exp. Stn 1965, 178179.Google Scholar
Bardner, R. (1968). Wheat bulb fly, Leptohylemyia coarctata Fall., and its effect on the growth and yield of wheat.—Ann. appl. Biol. 61, 111.CrossRefGoogle Scholar
Bardner, R. & Fletcher, K. E. (1969). The distribution of attacked plants.—Rep. Rothamsted exp. Stn 1968, Pt. 1, 199200.Google Scholar
Bardner, R. & Fletcher, K. E. (1973). A cause of variation in the distribution of infestations of wheat bulb fly (Leptohylemyia coarctata) within fields.—Entomologia exp. appl. 16, 3138.CrossRefGoogle Scholar
Bardner, R., Fletcher, K. E. & Huston, P. (1970). Recent work on wheat bulb fly. In Proceedings of the fifth British Insecticide and Fungicide Conference,17th to 20th November, 1969,Brighton.—pp. 500504. London, British Crop Protection Council.Google Scholar
Bardner, R. & Huston, P. J. (1968). Effect of gaps on yield.—Rep. Rothamsted exp. Stn 1967, 207208.Google Scholar
Bardner, M, & Lofty, J. R. (1971). The distribution of eggs, larvae and plants within crops attacked by wheat bulb fly Leptohylemyia coarctata (Fall.).—J. appl. Ecol. 8, 683686.CrossRefGoogle Scholar
Bardner, R., Maskell, F. E. & Ross, G. J. S. (1970). Measurements of infestations of wheat bulb fly, Leptohylemyia coarctata (Fall.), and their relationship with yield.—Pl. Path. 19, 8287.CrossRefGoogle Scholar
Bardner, R. & Taylor, W. E. (1970). Effects of flea beetles on the yield of radish.—Entomologia exp. appl. 13, 5460.CrossRefGoogle Scholar
Beck, S. D. (1965). Resistance of plants to insects.—A. Rev. Ent. 10, 207232.CrossRefGoogle Scholar
Bornemissa, G. F. & Williams, C. H. (1970). An effect of dung beetle activity on plant yield.—Pedobiologia 10, 17.CrossRefGoogle Scholar
Boyer, W. P. (1967). The effect of type of plant growth on bollworm (Heliothis zea) infestations in soybeans in Arkansas.—Co-op, econ. Insect Rep. 17, 8386.Google Scholar
Brazzel, J. R. & Gaines, J. C. (1957). Cotton yield and quality losses caused by various levels of pink bollworm infestations.—J. econ. Ent. 50, 609613.CrossRefGoogle Scholar
Buckley, B. R. & Burkhardt, C. C. (1962). Corn earworm damage and loss in grain sorghum.—J. econ. Ent. 55, 435439.CrossRefGoogle Scholar
Bullock, J. A. (1965). The assessment of the effect of insecticides on infestations of Hylemyia arambourgi Séguy (Dipt.—Anthomyidae).—Int. Congr. Ent. 1964, 611.Google Scholar
Bundy, J. W. (1968). The significance of pest and disease damage in the production and marketing of processed vegetables. In Proceedings of the fourth British Insecticide and Fungicide Conference,20th–23rd November, 1967,Brighton.—pp. 534544. London, British Insecticide and Fungicide Council.Google Scholar
Bunting, A. H. & Drennan, D. S. H. (1966). Some aspects of the morphology and physiology of cereals in the vegetative phase. In Milthorpe, F. L. & Ivins, J. D. (Eds) The growth of cereals and grasses. Proceedings of the twelfth Easter School in Agricultural Science, University of Nottingham, 1965.—pp. 2038. London, Butterworths.Google Scholar
Canerday, T. D. & Arant, F. S. (1964). The effect of late season infestations of the strawberry spider mite, Tetranychus atlanticus, on cotton production.—J. econ. Ent. 57, 931933.CrossRefGoogle Scholar
Carlson, J. W. (1940). Lygus bug damage to alfalfa in relation to seed production.—J. agric. Res. 61, 791815.Google Scholar
Chiang, H. C. (1964). The effects of feeding site on the interaction of the European corn borer, Ostrinia nubilalis and its host, the field corn Zea mays.—Entomologia exp. appl. 7, 144148.CrossRefGoogle Scholar
Chiang, H. C. (1965). Relation of Ostrinia nubilalis (Hbn.) to the growth and yield of Zea mays (L.).—Int. Congr. Ent. 1964, 605607.Google Scholar
Chiang, H. C. & Holdaway, F. G., Brindley, T. A. & Neiswander, C. R. (1960). European corn borer populations in relation to the estimation of crop loss.—J. econ. Ent. 53, 517522.CrossRefGoogle Scholar
Chiarappa, L. (Ed.) (1971). Crop loss assessment methods. FAO manual on the evaluation and prevention of losses by pests, diseases and weeds.—170 pp. Farnham Royal, Commonwealth Agricultural Bureaux.Google Scholar
Coaker, T. H. (1957). Studies of crop loss following insect attack on cotton in East Africa. II.—Further experiments in Uganda.—Bull. ent. Res. 48, 851866.CrossRefGoogle Scholar
Coaker, T. H. (1965). The effect of irrigation on the yield of cauliflowers and cabbage crops damaged by the cabbage root fly.—Pl Path. 14, 7582.CrossRefGoogle Scholar
Coaker, T. H. & Finch, S. (1971). The cabbage root fly, Erioischia brassicae (Bouché).—Rep. natn. Veg. Res. Stn 1970, 2342.Google Scholar
Coghill, K. J. (1970). The effect of fruit tree red spider mite on yields of apple. In Proceedings of the fifth British Insecticide and Fungicide Conference,17th to 20th November, 1969, Brighton.—pp. 495499. London, British Crop Protection Council.Google Scholar
Cramer, H. H. (1967). Plant protection and world crop production.—Pflschulz-Nachr. Bayer 20, 1524.Google Scholar
Cunliffe, N. (1928). Studies on Oscinella frit Linn. Observations on infestation and yield, susceptibility to infestation, recovery power, the influence of variety on the rate of growth of the primary shoot of the oat and the reaction to manurial treatment.—Ann. appl. Biol. 15, 473487.CrossRefGoogle Scholar
Davidson, R. L. & Roberts, R. J. (1969). Scarab damage to grass and clover as influenced by depth of feeding.—Bull. ent. Res. 58, 559565.CrossRefGoogle Scholar
Deay, H. O., Patch, L. H. & Snelling, R. O. (1949). Loss in yield of dent corn infested with the August generation of the European corn borer.—J. econ. Ent. 42, 8187.CrossRefGoogle Scholar
Debach, P. (1964). Biological control of insect pests and weeds.—844 pp. London, Chapman & Hall.Google Scholar
Decker, G. C. (1954). A century of insect losses.—Agric. Chem. 9 (8), 4041.Google Scholar
De Wit, C. T. (1960). On competition.—Versl. landb. Onderz. 66 (8), 182.Google Scholar
Dixon, A. F. G. (1971 a). The role of aphids in wood formation. I. The effect of sycamore aphid Drepanosiphum platanoides (Schr.) (Aphididae), on the growth of sycamore, Acer pseudoplatanus (L.).—J. appl. Ecol. 8, 165179.CrossRefGoogle Scholar
Dixon, A. F. G. (1971 b). The role of aphids in wood formation. II. The effect of the lime aphid Eucallipterus tiliae L. (Aphididae), on the growth of lime, Tilia × vulgaris Hayne.—J. appl. Ecol. 8, 393399.CrossRefGoogle Scholar
Doane, J. F. & Chapman, R. K. (1964). The relation of the cabbage maggot Hylemyia brassicae (Bouché) to decay in some cruciferous crops.—Entomologia exp. appl. 7, 18.CrossRefGoogle Scholar
Dunning, R. A. (1957). Mirid damage to seedling beet.—Pl Path. 6, 1920.CrossRefGoogle Scholar
Eastin, J. D., Haskins, F. A., Sullivan, C. Y. & Bauel, C. H. M. (Eds) (1969). Physiological aspects of crop yield. Proceedings of a symposium sponsored by the University of Nebraska, the American Society of Agronomy and the Crop Science Society of America and held at the University of Nebraska, January 20–24, 1969.—396 pp. Madison, Wisconsin, American Society of Agronomy.Google Scholar
Empson, D. W. (1958). Frit fly and the oat panicle.—Ann. appl. Biol. 46, 479482.CrossRefGoogle Scholar
Eyles, A. C. (1965). Damage to cultivated Cruciferae by Nysius huttoni White (Heteroptera: Lygaeidae).—N.Z. Jl agric. Res. 8, 363366.CrossRefGoogle Scholar
Finney, D. J. (1941). Wireworm populations and their effect on crops.—Ann. appl. Biol. 28, 282295.CrossRefGoogle Scholar
Finney, D. J. (1971). Probit analysis.—3rd edition.—334 pp. London, Cambridge University Press.Google Scholar
Free, J. B. (1970). Insect pollination of crops.—544 pp. London, Academic Press.Google Scholar
George, K. S. (1962). Root nodule damage by larvae of Sitona lineatus, and its effect on yield of green peas.—Pl Path. 11, 172176.CrossRefGoogle Scholar
Gibson, R. W. (1974). The induction of top-roll symptoms on potato plants by the aphid Macrosiphum euphorbiae.—Ann. appl. Biol. 76, 1926.CrossRefGoogle Scholar
Gould, H. J. & Graham, C. W. (1969). The control of Aphis fabae Scop, on spring-sown field beans (Vicia faba L.).—Ann. appl. Biol. 64, 110.CrossRefGoogle Scholar
Gruys, P. (1970). Growth in Bupalus piniarius (Lepidoptera: Geometridae) in relation to larval population density.—127 pp. Wageningen, PUDOC, Centre for Agricultural Publishing and Documentation. (Verhandelingen Rijksinstituut voor Naturbeheer no. 1).Google Scholar
Harries, F. H. (1966). Reproduction and mortality of the two-spotted spider mite on fruit seedlings treated with chemicals.—J. econ. Ent. 59, 501506.CrossRefGoogle Scholar
Harris, K. M. (1962). Lepidopterous stem borers of cereals in Nigeria.—Bull. ent. Res. 53, 139171.CrossRefGoogle Scholar
Harris, K. M. (1965). The effect of lepidopterous stem borers on the yields of cereals in N. Nigeria.—Int. Congr. Ent. 1964, 610.Google Scholar
Harvey, T. L. & Hackerott, H. L. (1970). Chemical control of a greenbug on sorghum and infestation effects on yield.—J. econ. Ent. 63, 15361539.CrossRefGoogle Scholar
Heathcote, G. D. & Cockbain, A. J. (1966). Aphids from mangold clamps and their importance as vectors of beet viruses.—Ann. appl. Biol. 57, 321336.CrossRefGoogle Scholar
Hussey, N. W. & Parr, W. J. (1963). The effect of glasshouse red spider mite (Tetranychus urticae Koch) on the yield of cucumbers.—J. hort. Sci. 38, 255263.CrossRefGoogle Scholar
Ingram, W. R. (1969). Further studies of crop loss following insect attack on cotton in Uganda.—Bull. ent. Res. 59, 6576.CrossRefGoogle Scholar
Isaak, A., Sorenson, E. L. & Ortman, E. E. (1963). Influence of temperature and humidity on resistance in alfalfa to the spotted alfalfa aphid and pea aphid.—J. econ. Ent. 56, 5357.CrossRefGoogle Scholar
Jacobson, L. A. (1965). Damage to wheat by Say stink bug Chlorochroa sayi.—Can. J. Pl. Sci. 45, 413417.CrossRefGoogle Scholar
Jacobson, L. A. & Peterson, K. (1965). Interrelations of damage to wheat and feeding by the pale western cutworm, Agrotis orthogonia Morrison (Lepidoptera: Noctuidae).—Can. Ent. 97, 153158.CrossRefGoogle Scholar
Johnson, C. G. (1950). Infestation of a bean field by Aphis fabae Scop, in relation to wind direction.—Ann. appl. Biol. 37, 441450.CrossRefGoogle Scholar
Johnson, C. G. (1965). A focal point for insect ecology in agriculture.—Pest Artic. & News Summ. (PANS) (A) 11, 366368.Google Scholar
Johnson, C. G. (1969). Migration and dispersal of insects by flight.—763 pp. London, Methuen.Google Scholar
Johnson, C. G., Lofty, J. R. & Cross, D. J. (1969). Insect pests on Broadbalk.—Rep. Rothamsted exp. Stn 1968, Pt. 2, 141156.Google Scholar
Jones, F. G. W., Dunning, R. A. & Humphries, K. P. (1955). The effects of defoliation and loss of stand upon yield of sugar beet.—Ann. appl. Biol. 43, 6370.CrossRefGoogle Scholar
Jones, F. G. W. & Jones, M. G. (1974). Pests of field crops.—2nd edn, 488 pp. London, Edward Arnold.Google Scholar
Judenko, E., Johnson, C. G. & Taylor, L. R. (1952). The effect of Aphis fabae Scop. on the growth and yield of field beans in a garden plot.—Pl. Path. 1, 6063.CrossRefGoogle Scholar
Justesen, S. H. & Tammes, P. M. L. (1960). Studies of yield losses. 1. The self-limiting effect of injurious or competitive organisms on crop-yield.—Tijdschr. Plziekt. 66, 281287.Google Scholar
Kennedy, J. S. (1958). Physiological condition of the host-plant and susceptibility to aphid attack.—Entomologia exp. appl. 1, 5065.CrossRefGoogle Scholar
Kinkade, R. T., Laster, M. L. & Hartwig, E. E. (1971). Simulated pod injury to soy beans.—J. econ. Ent. 64, 984985.CrossRefGoogle Scholar
Kinzer, H. G. & Henderson, C. F. (1968). Damage by larvae of the corn earworm to grain sorghum.—J. econ. Ent. 61, 263267.CrossRefGoogle Scholar
Kirby, E. J. M. (1968). Plant density and yield in cerealsN.A.A.S. q. Rev. no. 80, 139145.Google Scholar
Klostermeyer, E. C. (1962). The relationship among pea aphids, lygus bugs and alfalfa seed yields.—J. econ. Ent. 55, 462465.CrossRefGoogle Scholar
Kulman, H. M. (1971). Effects of insect defoliation on growth and mortality of trees.—A. Rev. Ent. 16, 289324.CrossRefGoogle Scholar
Kuznetsov, V. S. & Bebin, S. I. (1965). Agrobiological basis of topping in fodder beans.—Izv. timiryazev. sel'.-khoz. A kad. no. 1, 100109.Google Scholar
Leach, J. G. (1940). Insect transmission of plant diseases.—615 pp. New York, McGraw-Hill.Google Scholar
Leakey, C. L. A. & Perry, D. A. (1966). The relation between damage caused by insect pests and boll rot associated with Glomerella cingulata (Stonem.) Spauld von Schrenk and Colletotrichum gossypii Southw. on upland cotton in Uganda.—Ann. appl. Biol. 57, 337344.CrossRefGoogle Scholar
Lewis, T. (1966). An analysis of components of wind affecting the accumulation of flying insects near artificial windbreaks.—Ann. appl. Biol. 58, 365370.CrossRefGoogle Scholar
Lewis, T. (1967). The horizontal and vertical distribution of flying insects near artificial windbreaks.—Ann. app. Biol. 60, 2331.CrossRefGoogle Scholar
Lewis, T. & Stephenson, J. W. (1966). The permeability of artificial windbreaks and the distribution of flying insects in the leeward sheltered zone.—Ann. appl. Biol. 58, 355363.CrossRefGoogle Scholar
Macfadyen, A. (1963). Animal ecology: aims and methods.—2nd edn, 344 pp. London, Pitman.Google Scholar
Macfadyen, A. (1967). Methods of investigation of productivity of invertebrates in terrestrial ecosystems. In Petrusewicz, K. (Ed.). Secondary productivity of terrestrial ecosystems. (Principles & methods.) Proceedings of working meeting held in Jabonna 31.8–6.9. 1966. Vol. 2. pp. 383412. Warsaw, Institute of Ecology, Polish Academy of Sciences/Polish International Biological Programme.Google Scholar
Maramorosch, K. (1963). Arthropod transmission of plant viruses.—A. Rev. Ent. 8, 369414.CrossRefGoogle ScholarPubMed
Maramorosch, K. (Ed.) (1969). Viruses, vectors and vegetation.—666 pp. New York, Interscience.Google Scholar
Mazanec, Z. (1968). Influence of defoliation by the phasmatid Didymuria violescens on seasonal diameter growth and the pattern of growth rings in alpine ash.—Aust. For. 32, 314.CrossRefGoogle Scholar
McEwen, J. (1972). Effects of defoliating different zones on the plant in field beans (Vicia faba L.).—J. agric. Sci. Camb. 78, 487490.CrossRefGoogle Scholar
Mckinlay, K. S. (1965). Insect damage, crop formation and the yield of coconuts.—Bull. ent. Res. 56, 6778.CrossRefGoogle Scholar
Mckinlay, K. S. & Geering, Q. A. (1957). Studies of crop loss following insect attack on cotton in East Africa. I. Experiments in Uganda and Tanganyika.—Bull. ent. Res. 48, 833849.CrossRefGoogle Scholar
Metcalf, C. L. & Flint, W. P. (1962). Destructive and useful insects. 4th edn revised by R. L. Metcalf.—1087 pp. New York, McGraw-Hill.Google Scholar
Miles, P. W. (1968). Insect secretions in plants.—A. Rev. Phytopathol. 6, 137164.CrossRefGoogle Scholar
Mittler, T. E. & Sylvester, E. S. (1961). A comparison of the injury to alfalfa by the aphids Therioaphis maculata and Macrosiphum pisi.—J. econ. Ent. 54, 615622.CrossRefGoogle Scholar
Nixon, G. E. J. (1951). The association of ants with aphids and coccids.—36 pp. London, Commonwealth Institute of Entomology.Google Scholar
Nuorteva, P. (1962). Studies on the causes of the phytopathogenicity of Calligypona pellucida (F.) (Hom., Araeopidae).—Suomal. eläin-ja kasvit. Seur. van. Julk. 23 (4), 158.Google Scholar
Ogborn, J. E. A. & Proctor, J. H. (1962). Bollworm attack and the water status of the cotton crop.—Emp. Cott. Grow. Rev. 39, 131135.Google Scholar
Ordish, G. (1960). Agricultural pests in history.—Span 3, 2226.Google Scholar
Ordish, G. & Toft, H. (1965). Loss of economic yield in crops.—Int. Congr. Ent. 1964, 603605.Google Scholar
Painter, R. H. (1951). Insect resistance in crop plants.—520 pp. New York, Macmillan.Google Scholar
Painter, R. H. (1958). Resistance of plants to insects.—A. Rev. Ent. 3, 267290.CrossRefGoogle Scholar
Phillipson, J. (1966). Ecological energetics.—57 pp. London, Edward Arnold.Google Scholar
Pimentel, D. (1971). Population control in crop systems: monocultures and plant spatial patterns. In Proceedings of the second Tall Timbers conference on ecological animal control by habitat management, 1970.—pp. 209221. Tallahassee, Florida, Tall Timbers Research Station.Google Scholar
Pritam, Singh (1970). Host-plant nutrition and composition: effects on agricultural pests.—Inf. Bull. Belleville Res. Inst., Can. Dep. Agric., 102 pp.Google Scholar
Radcliffe, E. B. & Chapman, R. K. (1965). Seasonal shifts in the relative resistance to insect attack of eight commercial cabbage varieties.—Ann. ent. Soc. Am. 58, 892897.CrossRefGoogle Scholar
Rautappää, J. (1966). The effect of the English gram aphid, Macrosiphum avenae (F.) (Horn., Aphididae), on the yield and quality of wheat.—Ann. Agric. fenn. 5, 334341.Google Scholar
Rautappää, J. (1968 a). Changes in the yield and protein quantity of oat caused by Rhopalosiphum padi (L.) (Horn., Aphididae).—Ann. Agric. fenn. 7, 95104.Google Scholar
Rautappää, J. (1968 b). Reduction in yield and changes in brewing quality of barley caused by Macrosiphum avenae (F.) (Horn., Aphididae).—Acta Agric. scand. 18, 233241.CrossRefGoogle Scholar
Rautappää, J. (1969). Effect of Lygus rugulipennis Popp. (Hem., Capsidae) on the yield and quality of wheat.—Suom. hyönt. Aikak. 35, 168175.Google Scholar
Rautappää, J. (1970). Effect of the meadow capsid bug, Leptoterna dolabrata (L.) (Het., Capsidae) on the yield and quality of wheat.—Suom. hyönt. Aikak. 36, 145152.Google Scholar
Riepma, W. P. (1954). Standruimte-onderzoek aan lupinen.—Versl. cent, landbouwk. Onderz., 105110.Google Scholar
Rodriguez, J. G. (1960). Nutrition of the host and reaction to pests. Biological and chemical control of plant and animal pests.—Publs Am. Ass. Advmt. Sci. 61, 149167.Google Scholar
Roebuck, A. (1933). Measurements in nature: or the toll of insect and other animal pests on the farms of Lindsey during 1932.—Trans. Lincs. Nat. Un., 7181.Google Scholar
Scales, A. L. & Furr, R. E. (1968). Relationship between the tarnished plant bug and deformed cotton plants.—J. econ. Ent. 61, 114118.CrossRefGoogle Scholar
Schurr, K. M. & Holdaway, F. G. (1965). The relationship between plant injury in maize and ovipositional preference of Ostrinia nubilalis (Hbn.) (European corn borer).—Int. Congr. Ent. 1964, 607608.Google Scholar
Scott, D. R. (1970). Feeding of lygus bugs (Hemiptera: Miridae) on developing carrot and bean seed: increased growth and yields of plants grown from that seed.—Ann. ent. Soc. Am. 63, 16041608.CrossRefGoogle Scholar
Seinhorst, J. W. (1965). The relation between nematode density and damage to plants.—Nematologica 11, 137154.CrossRefGoogle Scholar
Sinha, R. C. (1968). Recent work on leaf-hopper-transmitted viruses.—Adv. Virus Res. 13, 181223.CrossRefGoogle ScholarPubMed
Skuhravý, V. (1968). Einfluss der Entblätterung und des Kartoffelkäferfrasses auf die Kartoffelernte.—Anz. Schädlingsk. 41, 180188.Google Scholar
Smith, R. F. (1967). Principles of measurement of crop losses caused by insects. In United Nations, Food and Agriculture Organization. Papers presented at the FAO symposium on crop losses, Rome, 2–6 October, 1967.—pp. 205224. Rome, FAO.Google Scholar
Southwood, T. R. E. & Jepson, W. F. (1961). The frit fly—a denizen of grassland and a pest of oats.—Ann. appl. Biol. 49, 556557.CrossRefGoogle Scholar
Stadelbacher, E. A. (1964). Evaluation of the growth and yield of cucumber plants as affected by the feeding of known populations of the striped cucumber beetle, Acalymma vittata (Fab.).—149 pp. Thesis, University of Illinois.Google Scholar
Stern, V. M. (1973). Economic thresholds.—A. Rev. Ent. 18, 259280.CrossRefGoogle Scholar
Stern, V. M., Smith, R. F., Van Den Bosch, R. & Hagen, K. S. (1959). The integrated control concept.—Hilgardia 29 (2), 81101.CrossRefGoogle Scholar
Strickland, A. H. (1954). Assessment of cabbage aphid damage in commercial brussels sprout crops.—Pl. Path. 3, 107117.CrossRefGoogle Scholar
Strickland, A. H. (1956). Agricultural pest assessment. I.—The problem.—N.A.A.S. q. Rev. no. 33, 112118.Google Scholar
Strickland, A. H. (1957). Cabbage aphid assessment and damage in England and Wales, 1946–55.—Pl. Path. 6, 19.CrossRefGoogle Scholar
Strickland, A. H. & Bardner, R. (1967). A review of current methods applicable to measuring crop losses due to insects. In United Nations, Food and Agriculture Organization. Papers presented at the FAO symposium on crop losses, Rome, 2–6 October, 1967, pp. 289309. Rome, FAO.Google Scholar
Tammes, P. M. L. (1961). Studies of yield losses. II. Injury as a limiting factor of yield.—Tüdschr. PlZiekt 67, 257263.Google Scholar
Taylor, C. E. (1962 a). Factors influencing the infestation of a bean field by Aphis fabae Scop.—Entomologia exp. appl. 5, 105113.CrossRefGoogle Scholar
Taylor, C. E. (1962 b). The population dynamics of aphids infesting the potato plant with particular reference to the susceptibility of certain varieties to infestation.—Eur. Potato J. 5, 204219.CrossRefGoogle Scholar
Taylor, C. E. & Johnson, C. G. (1954). Wind direction and the infestation of bean fields by Aphis fabae Scop.—Ann. appl. Biol. 41, 107116.CrossRefGoogle Scholar
Taylor, L. R. (1961). Aggregation, variance and the mean.—Nature, Lond. 189, 732735.CrossRefGoogle Scholar
Taylor, L. R. (1965). A natural law for the spatial disposition of insects.—Int. Congr. Ent. 1964, 396397.Google Scholar
Taylor, L. R. (1970). Aggregation and the transformation of counts of Aphis fabae Scop, on beans.—Ann. appl. Biol. 65, 181189.CrossRefGoogle Scholar
Taylor, W. E. & Bardner, R. (1968 a). Leaf injury and food consumption by larvae of Phaedon cochleariae (Coleoptera: Chrysomelidae) and Plutella maculipennis (Lepidoptera: Plutellidae) feeding on turnip and radish.—Entomologia exp. appl. 11, 177184.CrossRefGoogle Scholar
Taylor, W. E. & Bardner, R. (1968 b). Effects of feeding by larvae of Phaedon cochleariae (F.) and Plutella maculipennis (Curt.) on the yield of radish and turnip plants.—Ann. appl. Biol. 62, 249254.CrossRefGoogle Scholar
Taylor, W. E. & Bardner, R. (1970). Energy relationships between larvae of Phaedon cochleariae (Coleoptera: Chrysomelidae) or Plutella maculipennis (Lepidoptera: Plutellidae) and radish or turnip plants.—Entomologia exp. appl. 13, 403406.CrossRefGoogle Scholar
Thorne, G. N. (1966). Physiological aspects of grain yield in cereals. In Milthorpe, F. L. & Ivins, J. D. (Eds). The growth of cereals and grasses. Proceedings of the twelfth Easter School in Agricultural Science, University of Nottingham, 1965.—pp. 88105. London, Butterworths.Google Scholar
Thorne, G. N. (1969). Physiology of grain yield.—N.A.A.S. q. Rev. no. 85, 4246.Google Scholar
Van Emden, H. F. (1965). The effect of uncultivated land on the distribution of cabbage aphid (Brevicoryne brassicae) on an adjacent crop.—J. appl. Ecol. 2, 171196.CrossRefGoogle Scholar
Van Emden, H. F. (1966). Plant insect relationships and pest control.—World Rev. Pest Contr. 5, 115123.Google Scholar
Van Emden, H. F. (1969). Plant resistance to aphids induced by chemicals.—J. Sci. Fd Agric. 20, 385387.CrossRefGoogle Scholar
Van Emden, H. F., Eastop, V. F., Hughes, R. D. & Way, M. J. (1969). The ecology of Myzus persicae.—A. Rev. Ent. 14, 197270.CrossRefGoogle Scholar
Walker, P. T. (1960). The relation between infestation by the stalk borer, Busseola fusca and yield of maize in East Africa.—Ann. appl. Biol. 48, 780786.CrossRefGoogle Scholar
Walters, H. J. (1969). Beetle transmission of plant viruses.—Adv. Virus Res. 15, 339363.CrossRefGoogle ScholarPubMed
Wareing, P. F. & Cooper, J. P. (1971). Potential crop production: a case study416 pp. London. Heinemann.Google Scholar
Watson, D. J. (1952). The physiological basis of variation in yield.—Adv. Agron. 4, 101145.CrossRefGoogle Scholar
Watson, D. J. (1956 a). Measurement of photosynthesis in field conditions.—Landbouwk. Tijdschr., 's-Grav. 68, 581589.Google Scholar
Watson, D. J. (1956 b). The physiological limitations of crop yield and the possibilities of increasing it.—Landbouwk. Tijdschr., 's-Grav. 68, 590594.Google Scholar
Watson, D. J. (1968). A prospect of crop physiology.—Ann. appl. Biol. 62, 19.CrossRefGoogle Scholar
Watson, M. A. & Plumb, R. T. (1972). Transmission of plant-pathogenic viruses by aphids.—A. Rev. Ent. 17, 425452.CrossRefGoogle Scholar
Way, M. J. (1961). Crop losses by insects and the problem of control.—Proc. Nutr. Soc. 20, 511.CrossRefGoogle ScholarPubMed
Way, M. J. & Heathcote, G. D. (1966). Interactions of crop density of field beans, abundance of Aphis fabae Scop., virus incidence and aphid control by chemicals.—Ann. appl. Biol. 57, 409423.CrossRefGoogle Scholar
Way, M. J., Bardner, R., Van Baer, R. & Aitkenhead, P. (1958). A comparison of high and low volume sprays for control of the bean aphid, Aphis fabae Scop, on field beans.—Ann. appl. Biol. 46, 399410.CrossRefGoogle Scholar
Westlake, D. F. (1963). Comparisons of plant productivity.—Biol. Rev. 38, 385425.CrossRefGoogle Scholar
White, R. M. (1946). Preliminary observations on some effects of artificial defoliation of wheat plants.—Scient. Agric. 26, 225229.Google Scholar
Wilson, M. C., Treece, R. E., Shade, R. E., Day, K. M. & Stivers, R. K. (1969). Impact of cereal leaf beetle larvae on yields of oats.—J. econ. Ent. 62, 699702.CrossRefGoogle Scholar