The present study aimed to determine the net reproductive rate (R0) and stable age distribution of the soybean leaf roller (Hedylepta indicata F.) on soybean (Glycine max L.). All experiments were conducted at the entomology laboratory of the School of Agriculture and Natural Resources, University of Phayao. At 24-h intervals, twelve pair of adult moths less than 24 hours, were transferred to a new set of host plants until all insects died. Consequently, the old host plants served as a source of the freshly laid eggs. The number of live daughters produced per day per female (mx) in her life time (lx) was determined and a net reproductive rate (R0) calculated. The results show a value of R0 6.808, indicating that a population of H. indicata had the capacity of multiply 6.808 times in each generation under the given conditions. The stable age distribution was constructed with 1-day-old eggs of H. indicata. A Petri dishes containing 20 eggs each on soybean leaves were incubated in a rearing room held at 25±2 °C and 70±2% RH with 12 hours photo-phase. Ten replicates were run for a total of 200 eggs tested. After hatching, the early instar larvae were transferred singly into a 6x6x3.5 cm plastic cage. A tender leaf was placed into the cage to provide food for larva. At 24-h intervals, larva in each cage was transferred to a new leaf and the duration of each stage of development was observed until adult emergence. Newly emerged adult moths were examined daily until all of them had died. The investigation reveals that when the population reached the stable age distribution, 89.1% consisted of immature stages, and 10.9% of the total number of individuals were adults. The innate capacity for increase (r) attained in the given environment and the finite rate of increase (λ) was 0.0744 and 1.0772 respectively. When the birth rate (b) 0.6634 exceeded the death rate (d) 0.5890 then the population of H. indicata increased over each succeeding time period.
Keywords: net reproductive rate, stable age distribution, soybean leaf roller, Hedylepta indicata, innate capacity for increase
Bapatla, K. G., Patil, R. H., & Yeddula, S. (2018). Impact of leaf damage by defoliators on yield of soybean as a sole crop and as a main crop in intercropping systems. International Journal of Pest Management, 64(1), 51-58. doi:10.1080/09670874.2017.1297508
Begon, M., & Mortimer, M. (1981). Population ecology; a unified study of animals and plants. Oxford, Boston, Melbourne: Blackwell Scientific Publications.
Birch, L. C. (1948). The Intrinsic Rate of Natural Increase of an Insect Population. Journal of Animal Ecology, 17(1), 15-26. doi:10.2307/1605
Biswas, G. C. (2013). Insect pests of soybean (Glycine Max L.), their nature of damage and succession with the crop stages. Journal of the Asiatic Society of Bangladesh, Science, 39(1), 1-8. doi:10.3329/
Biswas, G. C., & Das, P. G. (2011). Insect and mite pests diversity in the oilseed crops ecosystems in Bangladesh. Bangladesh Journal of Zoology, 39(2), 235-244. doi:10.3329/bjz.v39i2.10594
Biswas, G. C., Hossain, M. M., & Majumder, U. K. (2001). Screening of some soybean entries against leaf roller (Lamprosema indicata F.). Bangladesh Journal of Agricultural Research, 26(2), 295-300.
Biswas, G. C., & Islam, R. (2012). Infestation and management of leaf roller (Lamprosema indica Fab.) in soybean (Glycine max L.). Bangladesh Journal of Agricultural Research, 37(1), 19-25.
Caswell, H. (1982). Stable Population Structure and Reproductive Value for Populations with Complex Life Cycles. Ecology, 63(5), 1223-1231. doi:10.2307/1938847
Chi, H., & Liu, H. (1985). Two new methods for study of insect population ecology. Bulletin of the Institute of Zoology, Academia Sinica, 24, 225–240
FCRC. (2018). Insecticide performance in key insect pests control: Crop Research Institute and Renewable Energy Crops. Retrieved from http://www.fcrc.org.au/member-news/fcrc-2018-conference-highlights.
Fehr, W. R. (1989). Soybean, importance and distribution. In G. Robbelen, R. Keith Downey & A. Ashri (Eds.), Oilcrops of the World (pp. 283-300). London, United Kingdom: McGraw-Hill Education - Europe.
Krebs, C. J. (1972). Ecology: The experimental analysis of distribution and abundance. New York: Harper & Row.
Lewatanakarn, S., Sutayavirut, T., & Sepswadi, P. (1974). Study on biology of soybean leaf roller [Lamprosema diamenalis Guen. (leaf roller), Lamprosema indicata F. (leaf folder), Cacoecia micaceana Wkr. (leaf rolling caterpillar) in Thailand. Retrieved from https://www.semanticscholar.
Lotka, A. J. (1913). A natural population norm. I. Journal of the Washington Academy of Sciences, 3(9), 241-248.
Lotka, A. J. (1922). The Stability of the Normal Age Distribution. Proceedings of the National Academy of Sciences of the United States of America, 8(11), 339-345.
Meena, N. L., & Sharma, U. S. (2006). Effect of sowing date and row spacing on incidence of major insect-pests of soybean, Glycine max (L.) Merrill. Soybean Research, 4(1/6), 73-76.
Pimchan, C. (2004). Farmers' knowledge and practice on insect control of soybean pests of farmers in Sanpatong district, Chiang Mai province. Chiang Mai University, Chiang Mai.
Poole, R. W. (1974). An introduction to quantitative ecology. New York: McGraw-Hill Education
Raju, G. S., Khandwe, N., & Sharma, S. (2013). Efficacy of insecticides against defoliators and stem borers of soybean. Annals of Plant Protection Sciences, 21(2), 250-253.
Sachan, J. N., & Gangwar, S. K. (1980). Insect pests of soybean in Khasi Hills of Meghalaya and their control. Bulletin of Entomology (India), 21(1-2), 105-112.
Taylor, F. (1979). Convergence to the stable age distribution in populations of insects. The American Naturalist, 113(4), 511-530.
Varley, G. C., Gradwell, G. R., & Hassell, M. P. (1973). Insect population ecology: An analytical approach. Berkeley and Los Angeles: University of California Press
Zeng, W., Sun, Z., Lai, Z., Cai, Z., Chen, H., Yang, S., & Tang, X. (2018). Correlation analysis on transcriptomic and proteome of soybean resistance to bean pyralid (Lamprosema indicata). Scientia Agricultura Sinica, 51(7), 1244-1260. doi:10.3864/j.issn.0578-1752.2018.07.003
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