Latitudinal trends in herbivory and performance of an invasive species, common burdock (Arctium minus)
- 660 Downloads
Plants often lose natural enemies (herbivores and pathogens) while invading new geographic regions, as predicted by the Enemy Release Hypothesis. However, a similar reduction in attack might occur at a more local scale within an invader’s range as plants in marginal areas escape enemies that fail to find them or cannot maintain local populations. In this study, we test the hypothesis that isolated populations near the northern edge of an invader’s range escape the enemies present in more southern populations, using the non-native monocarpic biennial, common burdock (Arctium minus), as a model species. In southern Ontario, this plant is attacked by a wide range of insect herbivores, including generalist leaf chewers as well as leaf-mining flies (Liriomyza arctii, Calycomyza flavinotum) and an abundant lepidopteran seed predator (Metzneria lappella). Surveys over an 815 km transect from temperate southern to boreal northern Ontario indicate that damage by all of these enemies declines sharply with latitude, while plants in more northern areas are slightly larger and more fecund. Critically, seed parasitism drops from more than 85 % in the south to less than 25 % in the north. These results indicate that populations of Arctium near this species’ northern limit escape many of their usual natural enemies, potentially counteracting less favourable environmental conditions. Such escape from enemies near invaders’ range margins may accelerate further spread, including expected migration in response to climate change.
KeywordsHerbivory Latitudinal gradient Leaf miners Metzneria lappella Physical defense
This work was supported by NSERC Research and Equipment Grants, with assistance from the Ontario Ministry of Natural Resources and the Koffler Scientific Reserve. We would especially like to thank Johanna Perz, Diane Krajewski, Saba Haroon, and Kirushanth Gnanachandran for their assistance in the field and the lab, and Nash Turley and two anonymous reviewers for comments on the manuscript. This study complies with all local laws.
- Clausen JD, Keck D, Hiesey WM (1948) Experimental studies on the nature of species. III. Environmental responses of climatic races of Achillea. Carnegie Institute of Washington, Publication 581Google Scholar
- Coley PD, Aide TM (1991) Comparison of herbivory and plant defenses in temperate and tropical broad-leaved forests. In: Price PW, Lewinsohn TM, Fernandes GW, Benson WW (eds) Plant–Animal interactions: evolutionary ecology in tropical and temperate regions, Wiley, New York, pp 25–49Google Scholar
- Connell JH (1971) On the role of natural enemies in preventing competitive exclusion in some marine animals and in rain forest trees. In: Den Boer PJ and Gradwell G (eds) Dynamics of populations: Proceedings of the advanced study institute on dynamics of numbers of populations, Center for Agricultural Publishing and Documentation, Wageningen, pp 298–312Google Scholar
- Harvey KJ, Nipperess DA, Britton DR, Hughes L (2012) Australian family ties: does a lack of relatives help invasive plants escape natural enemies? Biol Invasions. doi: 10.1007/s10530-012-0239-4
- Hatcher MJ, Dunn AM (2011) Parasites in ecological communities: from interactions to ecosystems. Cambridge University Press, CambridgeGoogle Scholar
- Mackay J, Kotanen PM (2008) Local escape of an invasive plant, common ragweed (Ambrosia artemisiifolia L.), from above-ground and below-ground enemies in its native area. 1152–1161. doi: 10.1111/j.1365-2745.2008.01426.x
- Mitchell CE, Blumenthal D, Jarosík V, Puckett EE, Pysek P (2010) Controls on pathogen species richness in plants’ introduced and native ranges: roles of residence time, range size and host traits. Ecol Lett 13:1525–1535. doi: 10.1111/j.1461-0248.2010.01543.x PubMedCentralPubMedCrossRefGoogle Scholar
- Schoonhoven LM, van Loon JJA, Dicke M (2005) Insect-plant biology, 2nd edn. Oxford University Press, OxfordGoogle Scholar
- Strong DR, Lawton JH, Southwood R (1984) Insects on plants. Harvard University Press, Cambridge, MassachusettsGoogle Scholar
- Walther GR, Roques A, Hulme PE, Sykes MT, Pysek P, Kühn I, Zobel M, Bacher S, Botta-Dukát Z, Bugmann H, Czúcz B, Dauber J, Hickler T, Jarosík V, Kenis M, Klotz S, Minchin D, Moora M, Nentwig W, Ott J, Panov VE, Reineking B, Robinet C, Semenchenko V, Solarz W, Thuiller W, Vilà M, Vohland K, Settele J (2009) Alien species in a warmer world: risks and opportunities. Trends Ecol Evol 24:686–693. doi: 10.1016/j.tree.2009.06.008 PubMedCrossRefGoogle Scholar