Sampling Procedure and Temporal-Spatial Distribution of the Cabbage Aphid, Brevicoryne brassicae L. (Hemiptera: Aphididae), on Canola

Authors
1 Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, P. O. Box: 14115-336, Tehran, Islamic Republic of Iran.
2 Department of Plant Protection, Isfahan Research Center for Agriculture and Natural Resources, P. O. Box: 199-81785, Isfahan, Islamic Republic of Iran.
3 School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia.
Abstract
To estimate population density of the cabbage aphid, Brevicoryne brassicae (L.), a stratified random sampling was conducted in two unsprayed canola fields in Isfahan (central Iran) during 2011-2012. Population density was determined for apterous, and alates, as well as the total population, at two plant growth phases (PGP1: From plant emergence to the end of rosette, and PGP2: From the beginning of stem elongation to ripening) on the whole plant as the sampling unit. Sources of variation in the sampling procedure were analyzed with a nested analysis of variance (NANOVA). In PGP2, aphid density in upper (10-15 cm upper part of stem) and lower (the rest of stem) parts were compared using Student’s t-test. Temporal changes in spatial pattern during the growth season were evaluated using 1/k (aggregation index) and Lloyd’s Patchiness Index. Results showed that differences among fields accounted for the majority of total variation observed in aphid densities and the aphids significantly preferred upper parts of canola plants. Among different indices used for analyzing spatial distribution of the aphid, Taylor’s Power Law (TPL) described well the relationship between variance and mean of the population. In both PGPs spatial patterns of apterous, alates, and total population were aggregated, random, and aggregated, respectively. Estimates of 1/k and changes in the value of patchiness index revealed that the aphid population was aggregated at the beginning of rosette stage and became more dispersed with time.

Keywords


1. Afshari, A. and Dastranj, M. 2010. Density, Spatial Distribution and Sequential Sampling Plans for the Cereal Aphids Infesting Wheat Spike in Gorgan Region, Northern Iran. Plant Protec. (Sci. J. Agr.), 32: 89-102.
2. Afshari. A., Soleiman-Negadian, E. and Shishebor, P. 2009. Population Density and Spatial Distribution of Aphis gossypii Glover (Homoptera: Aphididae) on Cotton in Gorgan, Iran. J. Agr. Sci. Tech., 11: 27-38.
3. Badenhausser, I. 1994. Spatial Patterns of Alatae and Apterous Morphs of the Brachycaudus helicherisi (Homoptera: Aphididae) in Sunflower Fields. Environ. Entomol., 23: 1381-1390.
4. Behdad, E. 1996. Iran Phytomedicine Encyclopedia: Plant Pests, Diseases and Weeds. Volume 1. Yadbood Publication, Isfahan, Iran. 572PP.
5. Bliss, C. I. and Owen, A. R. G. 1958. Negative Binomial Distributions with a Common. K. Biometrika, 45: 37-58.
6. Buntin, G. D. 1994. Developing a Primary Sampling Program. In: “Handbook of Sampling Methods for Arthropods in Agriculture”, (Eds.): Pedigo, L. P. and Buntin, G. D.. CRC Press, PP. 99-115.
7. Celini, L. and Vaillant, J. 2004. A Model of Temporal Distribution of Aphis gossypii Glover (Homoptera: Aphididae) on Cotton. J. Appl. Entomol., 128: 133-138.
8. Costello, M.J. and Altieri, M.A. 1995. Aboundance, Growth Rate and Parasitism of Brevicoryne brassicae and Myzus persicae (Homoptera: Aphididae) on Broccoli Grown in Living Mulches. Agr. Ecosys. Environ., 52: 187-196.
9. Darbemamieh, M., Fathipour, Y. and Kamali, K. 2009. Bionomics of Cenopalpus irani, Bryobia rubrioculus and their Egg Predator Zetzellia mali (Acari: Tenuipalpidae, Tetranychidae, Stigmaeidae) in Natural Conditions. Mun. Entomol. Zool., 4: 341−354.
10. Davis, P. M. 1994. Statistics for Describing Populations, In: “Handbook of Sampling Methods for Arthropods in Agriculture”, (Eds.): Pedigo, L. P. and Buntin, G. D.. CRC Press, PP. 33-54.
11. Elliott, N. C. and Kieckhefer, R. W. 1986. Spatial Distributions of Cereal Aphids (Homoptera: Aphididae) in Winter Wheat and Spring Oats in South Dakota. Environ. Entomol., 16: 896-901.
12. Feng, M. G. and Nowierski, R. M. 1992. Variation in Spatial Pattern of the Russian Wheat Aphid (Homoptera: Aphididae) among Small Grains in the Northwestern United States. Environ. Entomol., 21: 1029-1034.
13. Green, R. H. 1966. Measurement of Non-randomness in Spatial Distributions. Res. Popul. Ecol., 8: 1-7.
14. Harper, F. R. and Berkenkamp, B. 1975. Revised Growth Stage Key for Brassica campestris and B. napus. Can. J. Plant Sci., 55: 657-658.
15. Hartley, S. and Shorrocks, S. 2002. A General Framework for the Aggregation Model of Coexistence. J. Anim. Ecol., 71: 651-662.
16. Iwao, S. 1968. A New Regression Method for Analyzing the Aggregation Pattern of Animal Populations. Res. Popul. Ecol., 10: 1-20.
17. Jansson, R. K. and Smilowitz, Z. 1985. Influence of Potato Plant Phenology on the Population Dynamics of the Green Peach Aphid, Myzus persicae (Homoptera: Aphididae). Environ. Entomol., 14: 7-11.
18. Khodayari, S., Fathipour, Y., Kamali, K. and Naseri, B. 2010. Seasonal Activity of Zetzellia mali (Stigmaeidae) and Its Preys Eotetranychus frosti (Tetranychidae) and Tydeus longisetosus (Tydeidae) in Unsprayed Apple Orchards of Maragheh, Northwestern of Iran. J. Agr. Sci. Tech., 12: 549-558.
19. Lloyd, M. 1967. Mean Crowding. J. Anim. Ecol., 36: 1-30.
20. Moradi-Vajargah, M., Golizadeh, A., Rafiee-Dastjerdi, H., Zalucki, M. P., Hassanpour, M. and Naseri, B. 2011. Population Density and Spatial Distribution Pattern of Hypera postica (Coleoptera: Curculionidae) in Ardabil, Iran. Not. Bot. Horti. Agro., 39: 42-48.
21. McCornack, B. P., Costamagna, A. C. and Ragsdale, D. W. 2008. Within-plant Distribution of Soybean Aphid (Hemiptera: Aphididae) and Development of Node-based Sample Units for Estimating Whole-Plant Densities on Soybean. J. Econ. Entomol., 101: 1488-1500.
22. Morisita, M. 1962. Iδ Index: A Measure of Dispersion of Individuals. Res. Popul. Ecol., 4: 1-7.
23. Myers, J. H. 1978. Selecting a Measure of Dispersion of Individuals. Environ. Entomol., 7: 619-621.
24. Rahmani, H., Fathipour, Y. and Kamali, K. 2010. Spatial Distribution and Seasonal Activity of Panonychus ulmi (Acari: Tetranychidae) and Its Pery Zetaellia mali (Acari: Stigmaeidae) in Apple Orchards of Zanjan, Iran. J. Agr. Sci. Tech., 12: 155-165.
25. Raworth, D. A., Frazer, B. D., Gilbert, N. and Wellington, W. G. 1984. Population Dynamics of the Cabbage Aphid, Brevicoryne brassicae (Homoptera: Aphididae) at Vancouver, British Colombia. I. Sampling Methods and Population Trends. Can. Entomol., 116: 861-870.
26. Smith-Gill, S. J. 1975. Cytophysiological Basis of Disruptive Pigmentary Patterns in the Leopard Frog Rana pipiens. II. Wild Type and Mutant Cell Specific Patterns. J. Morph., 146: 35-54.
27. Southwood, T. R. E. and Henderson, P. A. 2000. Ecological Methods. 3rd Edition, Blackwell Science, UK, 575PP.
28. Taylor, L. R. 1984. Assessing and Interpreting the Spatial Distribution of Insect Populations. Ann. Rev. Entomol., 29: 321-357.
29. Trumble, J. T. 1982. Aphid (Homoptera: Aphididae) Population Dynamics on Broccoli in an Interior Valley of California. J. Econ. Entomol., 75: 841-847.
30. Ward, S. A. R., Chambers, J., Sunderland, K. and Dixon, A. F. G. 1986. Cereal Aphid Populations and the Relation between Mean Density and Spatial Variance. Netherl. J. Plant Pathol., 92: 127-132.
31. Wilson, L. T. 1994 Estimating Abundance, Impact, and Interactions among Arthropods in Cotton Agro Ecosystems, In: “Handbook of Sampling Methods for Arthropods in Agriculture”, (Eds.): Pedigo, L. P. and Buntin, G. D.. CRC Press, PP. 475-514.