Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, P. O. Box: 14115-336, Tehran, Iran.
Cold hardiness is one of the most common adaptations of insects at low temperatures. To understand the cold hardiness strategy of beet armyworm, Spodoptera exigua (Hübner), six temperature treatments were tested on the last instar larvae. Supercooling points of treatments were not significantly different. Two sugars, glucose and trehalose, as well as three polyols, myo-inositol, glycerol and sorbitol, were identified in these larvae. Trehalose was more affected in response to low temperatures in longer duration, and had a significant negative correlation with glycogen content. Despite the extensive sugar beet cultivation areas in Iran, beet armyworm population has been decreased in recent years. It seems that climate change regarding the global warming especially in autumn and winter could be a reason for decline in population outbreak of beet armyworm in the next generation. Based on findings of this study, it is suggested that overwintering larvae are freeze-intolerant insects but long term acclimation at sub-zero temperatures makes larvae tolerate presence of ice crystals in their body fluid.
Atapour, M. and Moharramipour, S. 2009. Changes of cold hardiness, supercooling capacity and major cryoprotectants in overwintering larvae of the rice stem borer, Chilo suppressalis Walker (Lepidoptera: Pyralidae). Environmental Entomology, 38 (1), 260-265.
Atapour, M. and Moharramipour, S. 2011a. Association of cold acclimation with freezing tolerance induction in the beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae). Applied Entomology and Phytopathology, 79 (2): 219-235 (In Persian with English abstract).
Atapour, M. and Moharramipour, S. 2011b. Changes in supercooling point and glycogen reserves in overwintering larvae and laboratory-reared samples of beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) to determining of cold hardiness strategy. Applied Entomology and Phytopathology, 78 (2): 199-216. [In Persian with English abstract].
Block, W. 1991. To freeze or not to freeze? Invertebrate survival of sub-zero temperatures. Functional Ecology, 5: 284-290.
Crowe, J. H., Crowe, L. M., Carpenter, J. F. and Aurell Wistrom, C. 1987. Stabilization of dry phospholipids bilayers and proteins by sugars. Biochemical Journal, 242: 1-10.
Danks, H. V. 2006. Insect adaptation to cold and changing environments. The Canadian Entomologist, 138: 1-23.
Ding, L., Li, Y. and Goto, M. 2003. Physiological and biochemical changes in summer and winter diapause and non-diapause pupae of the cabbage armyworm, Mamestra brassicae L. during long-term cold acclimation. Journal of Insect Physiology, 49: 1153-1159.
Elbein, A. D., Pan, Y. T., Pastuszak, I. and Carroll, D. 2003. New insights on trehalose: a multifunctional molecule. Glycobiology, 13: 17R-27R.
Goto, M., Fujii, M., Suzuki, K. and Sakai, M. 1998. Factors affecting carbohydrate and free amino acid content in overwintering larvae of Enosima leucotaeniella. Journal of Insect Physiology, 44 (1): 87-94.
Hansen, R. G., Rutter, W. J. and Craine, E. M. 1951. A nephelometric method for the determination of glycogen. Journal of Biological Chemistry, 195: 127-132.
Khanjani, M. 2005. Pests of Field Crops in Iran. Buali Sina University Press, Hamedan, 720 pp.
Kheyri, M. 1976. Investigation on outbreak on the beet armyworm Spodoptera exigua Hb. (Lep. Noctuidae). Applied Entomology and Phytopathology, 42: 1-15. [In Persian with English summary].
Kheyri, M. 1985. Investigation in the biology and population fluctuation of beet armyworm, Spodoptera exigua (Hb) in Karaj, Iran. A thesis submitted in partial fulfillment of the Doctorate degree. Tehran University (In Persian with English abstract).
Kheyri, M. 1989. An inventory of pests attacking sugar beet in Iran. Applied Entomology and Phytopathology, 56 (1and2): 75-91 (In Persian with English abstract).
Kim, Y. and Kim, N. 1997. Cold hardiness in Spodoptera exigua (Lepidoptera:Noctuidae). Physiological and Chemical Ecology, 26 (5): 1117-1123.
Kim, Y. and Song, W. 2000. Effect of thermoperiod and photoperiod on cold tolerance of Spodoptera exigua (Lepidoptera: Noctuidae). Physiological and Chemical Ecology, 29 (5): 868-873.
Kostal, V. and Simek, P. 1995. Dynamics of cold hardiness. Supercooling and cryoprotectants in diapausing and non-diapausing pupae of the cabbage root fly, Delia radicum L. Journal of Insect Physiology, 41 (7): 627-637.
Kostal, V., Slachta, M. and Simek, P. 2001. Cryoprotective role of polyols independent of the increase in supercooling capacity in diapausing adults of Pyrrhocoris apterus (Heteroptera: Insecta). Journal of Insect Physiology, 130 (B): 365-374.
Kostal, V., Zahradnickova, H., Simek, P. and Zeleny, J. 2007. Multiple component system of sugars and polyols in the overwintering spruce bark beetle, Ips typographus. Journal of Insect Physiology, 53: 580-586.
Lee, R. E. 1991. Principles of insect low temperature tolerance. In: Lee, R. E. and Denlinger, D. L. (Eds.), Insect at Low Temperatures, Chapman and Hall, New York. pp. 17-46.
Li, Y-P., Goto, M., Ito, S., Sato, Y., Sasaki, K. and Goto, N. 2001. Physiology of diapause and cold hardiness in the overwintering pupae of the fall webworm Hyphantria cunea in Japan. Journal of Insect Physiology, 47: 1181-1187.
Malek zade, M. 2009. Effects of different irrigation systems on the infection of Spodoptera exigua and Spodoptera littoralis larvae in the sugar beet fields. Journal of Sugar Beet, 25 (2): 163-174.
Mehrkhou, F. 2011. Effect of different soybean varieties on proteolytic activities of digestive enzymes and demographic parameters of, Spodoptera exigua (Lepidoptera: Noctuidae). Ph. D. Dissertation, Tarbiat Modares University, Tehran. 164 pp.
Neven, L. G. 1999. Cold hardiness adaptation of codling moth, Cydia pomonella. Cryobiology, 38: 43-50.
Abdollahian Noghabi, M. 2007. A review on growth and production of sugar beet crops in Iran during the recent years. Journal of Sugar Beet, 23 (2): 197-199.
Rojas, R. R., Charlet, L. D. and Leopold, R. A. 1991. Biochemistry and physiology of overwintering in the mature larvae of the sunflower seed weevil, Smicronyx fulvus leconte (Coleoptera: Curculionidae) in the Northern Great Plains. Journal of Insect Physiology, 37: 489-496.
Rojas, R. R. Charlet, L. D. and Leopold, R. A. 1994. Biochemistry and physiology of overwintering in the mature larvae of the sunflower stem weevil, Cylindrocopturus adspersus (Coleoptera: Curculionidae) in the Northern Great Plains. Journal of Insect Physiology, 37: 489-496.
Rojas, R. R., Lee, R. E., Luu, T. A. and Baust, J. G. 1983. Temperature dependence-independence of antifreeze turnover in Eurosta solidaginis (Fitch). Journal of Insect Physiology, 29: 865-869.
Sinclair, B. J. 1999. Insect cold tolerance: how many kinds of frozen? European Journal of Entomology, 96: 157-164.
Sinclair, B. J. 2001. Field ecology of freeze tolerance: interannual variation in cooling rates, freeze-thaw and thermal stress in the microhabitat of the alpine cockroach Celatoblatta quinquemaculata. Oikos, 93: 286-293.
Storey, K. B., Keefe, D., Kourts, L. and Storey, J. M. 1991. Glucose-6-phosphate dehydrogenase in cold hardyinsects: Kinetic properties, freezing stabilization, and control of hexose monophosphate shunt activity. Insect Biochemistry, 21 (2): 157-164.
Storey, K. B. and Storey, J. M. 1988. Freeze tolerance in animals. Reviews of Physiology and Chemistry, 68: 27-84.
Storey, K. B. and Storey, J. M. 1991. Biochemistry of cryoprotectants. In: Lee, R. E. and Denlinger, D. L. (Eds.), Insects at Low Temperatures, Chapman and Hall, New York. pp. 64-93.
Woodman, J. D. 2010. Cold tolerance of first-instar nymphs of the Australian plague locust, Chortoicetes terminifera. Journal of Insect Physiology, 56: 376-379.
Zachariassen, K. E. 1985. Physiology of cold tolerance in insects. Physiological Reviews, 65: 799-832.