Climate change and forest plagues: the case of the pine

P. Seixas Arnaldo, I. Oliveira, J. Santos, S. Leite


The pine processionary moth, Thaumetopoea pityocampa (Den. & Schiff.) (Lep., Thaumetopoeidae) is known as the most defoliating insect in Pinus and Cedrus in many countries. In the last three decades, climate change has led to a substantial expansion of its range and high attack rates in previously unaffected areas were observed. A 3-year analysis of the effect of several climatic elements on the T. pityocampa adult emergence was made and one climatic change scenario was tested in order to predict the insect’s behaviour in the future. Results showed that mean air temperature was the climatic element with the best single regression fit to adult emergence, whereas minimum air temperature and relative humidity provided the best multiple regression fits. Results also demonstrated that higher emergence of adults is often related to a maximum temperature above 30°C, a mean temperature above 23°C, a minimum temperature above 17°C, relative humidity lower than 60% and precipitation values lower than 10 mm. Using the same thresholds for future climatic conditions simulated by the COSMO-CLM model, the period for pine processionary moth emergence will be expanded, starting much sooner. Contrasting with the actual emergence period, the insect is projected to have favorable climatic conditions to start emerging in May. This might have serious implications in forest ecosystems, concerning not only ecological issues, but also forest management.


Thaumetopoea pityocampa; mean air temperature; relative humidity; simulation under climate changed

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Arnaldo P.S., 2003. Contribuição para o conhecimento da processionária do pinheiro, Thaumetopoea pityocampa (Den. & Schiff.). Morfologia, bioecologia e protecção contra a praga. Ph.D. thesis. Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal. 511 pp.

Arnaldo P., Chacim S., Lopes D., 2010. Effects of defoliation by the pine processionary moth Thaumetopoea pityocampa on biomass growth of young stands of Pinus pinaster in northern Portugal. iForest-Biogeosciences and Forestry 3(1), 159-162.

Ayres M.P., Lombardero M.J., 2000. Assessing the consequences of global change for forest disturbance from herbivores and pathogens. Science of The Total Environment 262(3), 263-286.

Bale J.S., Masters G.J., Hodkinson I.D., Awmack C., Bezemer T.M., Brown V.K., Butterfield J., Buse A., Coulson J.C., Farrar J., Good J.E.G., Harrington R., Hartley S., Jones T.H., Lindroth R.L., Press M.C., Symrnioudis I., Watt A.D., Whittaker J.B., 2002. Herbivory in global climate change research: direct effects of rising temperature on insect herbivores. Global Change Biology 8(1), 1-16.

Battisti A., Stastny M., Netherer S., Robinet C., Schopf A., Roques A., Larsson S., 2005. Expansion of geographic range in the pine processionary moth caused by increased winter temperatures. Ecological Applications 15(6), 2084-2096.

Battisti A., Stastny M., Buffo E., Larsson S., 2006. A rapid altitudinal range expansion in the pine processionary moth produced by the 2003 climatic anomaly. Global Change Biology 12(4), 662-671.

Benigni M., Battisti A., 1999. Climatic change and the adaptation of the pine processionary moth. Italia Forestale Montana, 54, 76-86.

Böhm U., Kücken M., Ahrens W., Block A. et al., 2006. CLM-the climate version of LM: brief description and long-term applications. COSMO News l6, 225-235.

Buxton R.D., 1983. Forest management and the pine processionary moth. Outlook on Agriculture 12, 34-39.

Carus S., 2004. Impact of defoliation by the pine processionary moth (Thaumetopoea pityocampa) on radial, height and volume growth of Calabrian pine (Pinus brutia) trees in Turkey. Phytoparasitica 32(5), 459-469.

Devkota B, Schmidt G.H., 1990. Larval development of Thaumetopoea pityocampa (Den. & Schiff.) (Lepidoptera, Thaumetopoeidea) from Greece as influenced by different host plants under laboratory conditions. Journal of Applied Entomology 209, 321-330.

Goussard F., Saintonge F.X., Geri C., 1999. Accroissement des risques de dégâts de la processionnaire du pin, Thaumetopoea pityocampa Denis & Schiff. en region Centre, du au réchauffement climatique (Lepidoptera, Thaumetopoeidae). Annales de la Société Entomologique de France 35, 341-343.

Hodar J.A., Castro J., Zamora R., 2003. Pine processionary caterpillar Thaumetopoea pityocampa as a new threat for relict Mediterranean Scots pine forests under climatic warming. Biological Conservation 110(1), 123-129.

Hodar J.A., Zamora R., 2004. Herbivory and climatic warming: a Mediterranean outbreaking caterpillar attacks a relict, boreal pine species. Biodiversity and Conservation 13(3), 493-500.

Huchon H., Demolin G., 1971. La bioecologie de la processionaire du pin. Dispersion potentielle. Dispersion actuelle. Phytoma 23, 11-20.

Kanat M., Hakki Alma M., Sivrikaya F., 2005. Effect of defoliationby Thaumetopoea pityocampa (Den. & Schiff. – Lepidoptera: Thaumetopoeidea) on annual diameter increment of Pinus brutia Ten. in Turkey. Annals des Sciences Forestieres 62, 91-94.

Lamy M., 1990. Contact dermatitis (erucism) produced by processionary caterpillars (Genus Thaumetopoea). Journal of Applied Entomology 110, 425-437.

Lautenschlager M., Keuler K., Wunram C., Keup-Thiel E. et al., 2009. Climate simulation with CLM, Scenario A1B run no.1, Data Stream 3: European region MPI-M/MaD. World Data Center for Climate. doi: 10.1594/WDCC/CLM_A1B_1_D3

Lindner M., García-Gonzalo J., Kolstro M.M., Green T., Reguera R., Maroschek M., Seidl R., Lexer M.J., Netherer S., Schopf A., Kremer A., Delzon S., Barbati A., Marchetti M., Corona P., 2008. Impacts of climate change on European forests and options for adaptation. Report to the European Commission Directorate-General for Agriculture and Rural Development, November 2008.

Malheiro A.C., Santos J.A., Fraga H., Pinto J.G., 2010. Climate change scenarios for viticultural zoning in Europe. Climate Research 43, 163-177. doi:1 0.3354/cr00918.

Masters G.J., Brown V.K, Clarke I.P., Whittaker J.B., Hollier J.A., 1998. Direct and indirect effects of climate change in insect herbivores: Auchenorrhyncha (Homoptera). Ecological Entomology 23, 45-52.

Nakicenovic N., Alcamo J., Davis G., De Vries B., Fenhann J., Gaffin S., Gregory K., Grübler A., Jung T.Y., Kram T., La Rovere E.L., Michaelis L., Mori S., Morita T., Pepper W., Pitcher H., Price L., Raihi K., Roehrl A., Rogner H.-H., Sankovski A., Schlesinger M., Shukla P., Smith S., Swart R., Van Rooijen S., Victor N., Dadi Z., 2000. Emissions scenarios. A Special Report of Working Group III of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK and New York, NY, USA. 599 pp.

Netherer S., Schopf, A., 2010. Potential effects of climate change on insect herbivores in European forests-General aspects and the pine processionary moth as specific example. Forest Ecology and Management 259(4), 831-838.

Oliveira P., Arnaldo P.S., Araújo M., Ginja M., Sousa A.P., Almeida O., Colaço A., 2003. Cinco casos clinicos de intoxicação por contacto com a larva Thaumetopoea pityocampa em cães. Revista Portuguesa de Ciências Clinicas 89(547), 81-84.

Peixoto J.P., Oort A.H., 1992. Physics of climate. American Institute of Physics, New York.

Robinet C., Roques A., 2010. Direct impacts of recent climate warming on insect populations. Integrative Zoology 5(2), 132-142. PMid:21392331

Rockel B., Will A., Hense A., 2008. The regional climate model COSMO-CLM. Meteorol Z (Berl) 17, 347-348.

Roeckner E., Brokopf R., Esch M., Giorgetta M., Hagemann S., Kornblueh L., 2006. Sensitivity of simulated climate to horizontal and vertical resolution in the ECHAM5 atmosphere model. J Climate 19:3771-3791. doi: 10.1175/JCLI3824.1.

Santos J.A., Malheiro A.C., Karremann M.K., Pinto J.G., 2010. Modelling of grapevine productivity in the Port Wine region for present and future climate conditions. International Journal of Biometeorology 55, 119-131. doi: 10.1007/s00484-010-0318-0.

Stastny M., Battisti A., Petrucco-Toffolo E., Schlyter F., Larsson S., 2006. Host-plant use in the range expansion of the pine processionary moth, Thaumetopoea pityocampa. Ecological Entomology 31(5), 481-490.

Yang Y., Stamp N.E., 1995. Simultaneous effects of night-time temperature and an allelochemical on performance of an insect herbivore. Oecologia 104(2), 225-233.

DOI: 10.5424/fs/20112003-11394