INTER-ANNUAL VARIATIONS IN PHENOLOGICAL EVENTS OF WILLOW (Salix alba) AND DEVELOPMENTAL STAGES OF GYPSY MOTH (Lymantria obfuscate), USING DEGREE DAY MODELS
DOI:
https://doi.org/10.48165/abr.2025.27.01.41Keywords:
Climatic variation, degree days, gypsy moth, phenology, plant-insect synchrony, Salix alba, Lymantria obfuscataAbstract
Climate variability plays a crucial role in regulating the phenological patterns of plants and the developmental dynamics of associated insects. This study examined the phenology of willow (Salix alba) and the developmental stages of the gypsy moth (Lymantria obfuscata) over two consecutive years (2022–2023) using Julian dates and accumulated degree days (DD). Significant inter-annual variations were observed in both plant and insect development. In 2022, vegetative bud burst occurred earlier (Julian day 53, 0.55 DD) than in 2023 (Julian day 60, 3.86 DD), with similar delays observed in flowering and late-season events. Increased DD requirements in 2023 suggest climatic influences on phenological timing.Gypsy moth development also showed temporal shifts. In 2022, key stages such as egg hatching and adult emergence occurred earlier and at lower DD thresholds compared to 2023. Adult emergence was recorded at Julian day 158 (945.30 DD) in 2022 and at day 165 (492.22 DD) in 2023, indicating altered developmental dynamics. Population peaks differed between years, with a mid-June peak in 2022 (40 individuals, 608.65 DD) and a delayed, smaller peak in 2023 (35 individuals, 593.88 DD). These findings highlight the influence of temperature on plant–insect synchrony and demonstrate the usefulness of degree-day models for predicting phenological responses under changing environmental conditions.
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Bita, C. E., & Gerats, T. (2013). Plant tolerance to high temperature in a changing environment: Scientific fundamentals and production of heat stress-tolerant crops. Frontiers in Plant Science, 4, 273. https://doi.org/10.3389/fpls.2013.00273
Buckley, L. B. (2022). Temperature-sensitive development shapes insect phenological responses to climate change. Current Opinion in Insect Science, 52, 100897. https://doi.org/10.1016/j.cois.2022.100897
Chuine, I., Garcia de Cortazar-Atauri, I., Kramer, K., & Hanninen, H. (2013). Plant development models. In M. D. Schwartz (Ed.), Phenology: An Integrative Environmental Science (pp. 275–293). Springer, Dordrecht, The Netherlands. https://doi.org/10.1007/978-94-007-6925-0_15
Chuine, I., & Regniere, J. (2017). Process-based models of phenology for plants and animals. Annual Review of Ecology, Evolution and Systematics, 48(1), 159–182.
Crimmins, T. M., Gerst, K. L., Huerta, D. G., Marsh, R. L., Posthumus, E. E., Rosemartin, A. H., et al. (2020). Short-term forecasts of insect phenology inform pest management. Annals of the Entomological Society of America, 113(2), 139–148.
Dhar, U., & Kachroo, P. (1983). Alpine Flora of Kashmir Himalaya. Scientific Publishers, Jodhpur, Rajasthan, India.
Didevarasl, A., Costa-Saura, J. M., Spano, D., Deiana, P., Snyder, R. L., Rechid, D., et al. (2025). The phenological phases of early and mid-late budbreak olive cultivars in a changing future climate over the Euro-Mediterranean region. European Journal of Agronomy, 168, 127658. https://doi.org/10.1016/j.eja.2025.127658
Ekholm, A., Faticov, M., Tack, A. J. M., & Roslin, T. (2022). Herbivory in a changing climate: Effects of plant genotype and experimentally induced variation in plant phenology on two summer-active lepidopteran herbivores and one fungal pathogen. Ecology and Evolution, 12(1), e8495. https://doi.org/10.1002/ece3.8495
Estrella, N., & Menzel, A. (2006). Responses of leaf colouring in four deciduous tree species to climate and weather in Germany. Climate Research, 32(3), 253–267.
Gage, E. A., & Cooper, D. J. (2005). Patterns of willow (Salix spp.) seed dispersal, seed entrapment, and seedling establishment in a heavily browsed montane riparian ecosystem. Canadian Journal of Botany, 83(6), 678–687.
Gray, D. R. (2018). Age-dependent developmental response to temperature: An examination in the gypsy moth (Lymantria dispar) and winter moth (Operophtera brumata). Insects, 9(2), 41. https://doi.org/10.3390/insects9020041
Gray, D. R., Ravlin, F. W., & Braine, J. A. (2001). Diapause in the gypsy moth: A model of inhibition and development. Journal of Insect Physiology, 47(2), 173–184.
Gupta, A., Singh, N. B., Choudhary, P., Sharma, J. P., & Sankhayan, H. P. (2014). Advances in agricultural practices. International Journal of Agriculture, Environment and Biotechnology, 7(2), 299–304.
Helfenstein, J., Bauer, L., Claluna, A., Bolliger, J., & Kienast, F. (2014). Landscape ecology meets landscape science. Landscape Ecology, 29(7), 1109–1113.
Hill, G. M., Kawahara, A. Y., Daniels, J. C., Bateman, C. C., & Scheffers, B. R. (2021). Climate change effects on animal ecology: Butterflies and moths as a case study. Biological Reviews, 96(5), 2113–2126.
Jenderek, M. M., Ambruzs, B. D., Holman, G. E., Carstens, J. D., Ellis, D. D., & Widrlechner, M. P. (2020). Salix dormant bud cryotolerance varies by taxon, harvest year, and stem-segment length. Crop Science, 60(4), 1965–1973.
Koch, K. (2015). Influence of temperature and photoperiod on embryonic development in Sympetrum striolatum. Physiological Entomology, 40(1), 31–40.
Kutsokon, N., & Khoma, Y. (2025). Effects of drought stress on spring bud development in poplar and willow clones. Dendrobiology, 93, 86–97.
Liebhold, A., Elkinton, J., Williams, D., & Muzika, R. (2000). What causes outbreaks of the gypsy moth in North America? Population Ecology, 42, 257–266.
Logan, J. A., Regniere, J., & Powell, J. A. (2003). Assessing the impacts of global warming on forest pest dynamics. Frontiers in Ecology and the Environment, 1(3), 130–137.
Mallard, F., Nolte, V., & Schlotterer, C. (2020). The evolution of phenotypic plasticity in response to temperature stress. Genome Biology and Evolution, 12(12), 2429–2440.
Marchenko, A. M., & Kuzovkina, Y. A. (2023). Notes on the taxonomy of Salix vitellina. Plants, 12(14), 2610. https://doi.org/10.3390/plants12142610
McMaster, G. S., & Wilhelm, W. W. (1997). Growing degree-days: One equation, two interpretations. Agricultural and Forest Meteorology, 87, 291–300.
Menzel, A., Sparks, T. H., Estrella, N., Keuler, N., & Aasa, A. (2006). European plant phenology and climate change. Global Change Biology, 12(1), 1–8.
Moriondo, M., Ferrise, R., Trombi, G., Brilli, L., Dibari, C., & Bindi, M. (2015). Modelling olive trees and grapevines in a changing climate. Environmental Modelling & Software, 72, 387–401.
Mosseler, A., & Papadopol, C. S. (1989). Seasonal isolation as a reproductive barrier among sympatric Salix species. Canadian Journal of Botany, 67, 2563–2570.
Munshi, N. A., Hussain, B., Malik, G. N., Yousuf, M., & Fatima, N. (2008). Efficacy of entomopathogenic fungus Fusarium pallidoroseum against gypsy moth Lymantria obfuscata. Journal of Entomology, 5(1), 59–61.
Olaya-Arenas, P., Cho, C. Y. L., Olmstead, D., DiPaola, A., Crowther, S., Degni, J., et al. (2024). Degree-day models for predicting adult Delia platura spring flight and first emergence. Journal of Economic Entomology, 117(5), 2181–2185.
Oliveira, N., Canellas, I., Fuertes, A., Pascual, S., González, I., Montes, F., et al. (2024). Beyond biomass production: Enhancing biodiversity while capturing carbon in short rotation coppice poplar plantations. Science of the Total Environment, 933, 172932. https://doi.org/10.1016/j.scitotenv.2024.172932
Orlandi, F., Ruga, L., & Fornaciari, M. (2020). Willow phenological modelling at different altitudes in central Italy. Environmental Monitoring and Assessment, 192, 737. https://doi.org/10.1007/s10661-020-08702-7
Parker, A. K., Garcia de Cortazar-Atauri, I., Van Leeuwen, C., & Chuine, I. (2011). General phenological model to characterise flowering and veraison of Vitis vinifera. Australian Journal of Grape and Wine Research, 17(2), 206–216.
Poethig, R. S. (2013). Vegetative phase change and shoot maturation in plants. Current Topics in Developmental Biology, 105, 125–152.
Praciak, A., Pasiecznik, N. M., Sheil, D., van Heist, M., Sassen, M., Correia, C. S., et al. (2013). The CABI Encyclopedia of Forest Trees. CABI Publishing, UK.
Regniere, J., & Nealis, V. G. (2007). Ecological mechanisms of population change during outbreaks of the spruce budworm. Ecological Entomology, 32(5), 461–477.
Regniere, J., Powell, J., Bentz, B., & Nealis, V. (2012). Effects of temperature on insect development, survival and reproduction. Journal of Insect Physiology, 58(5), 634–647.
Roonwal, M. L. (1979). Field-ecological studies on mass eruption and seasonal life-history of Lymantria mathura. Records of the Zoological Survey of India, 75, 209–223.
Saska, M. M., & Kuzovkina, Y. A. (2010). Phenological stages of willow (Salix). Annals of Applied Biology, 156(3), 431–437.
Schwartz, M. D. (Ed.). (2013). Phenology: An Integrative Environmental Science (2nd ed.). Springer, Dordrecht.
van Asch, M., & Visser, M. E. (2007). Phenology of forest caterpillars and their host trees. Annual Review of Entomology, 52, 37–55.
Vitasse, Y., Francois, C., Delpierre, N., Dufrene, E., Kremer, A., Chuine, I., et al. (2011). Effects of climate change on European temperate trees. Agricultural and Forest Meteorology, 151(7), 969–980.
Wagay, O. A., Mugloo, J. A., Masoodi, T. H., Pala, N. A., Hussain, B., Khan, I., et al. (2024). Floral biology of Salix alba in Kashmir Himalayas. International Journal of Environment and Climate Change, 14(7), 714–723.
Wei, J., Luo, Y. Q., Shi, J., Wang, D. P., & Shen, S. W. (2014). Impact of temperature on diapause of the Asian gypsy moth (Lymantria dispar asiatica). Journal of Insect Science, 14, 5. https://doi.org/10.1093/jisesa/ieu119
