Pathogens as Biological Weapons of Invasive Species

摘要: Invasive species arenonindigenousspecies that areintroduced intonew environments, wheretheybecome established and expand theirrange[1].They undergo rapidproliferation follow-ingthecolonizationofnewhabitats,oftenattheexpense ofnative species, thushavinganega-tiveimpactonbiodiversity. Theprosperingdiscipline ofinvasionecology seekstounderstandwhysomespeciesbecomesuccessfulinvaders,whileothersdonot,eveniftheyarecloselyrelat-ed.Pathogens parasites appear toplayanimportantroleinthiscontext.Theenemy releasehypothesis proposes thatinvasivespecies aremorecompetitivein newlycolonizedhabitatsbe-causetheirnatural enemies, includingpathogens parasites,areleft behind intheirnativerange[2].Alternatively, thenovel weaponshypothesis invasivespecies haveac-quired chemical weaponsthat provideaselectiveadvantageovertheircompetitors [3]. Thereisnowconvincingevidencethatthenovelweaponshypothesiscanbeexpandedtoincludepatho-gensand thatarevectoredbytheinvasive intonewly colonizedhabitats[1].Thesepathogens canactas biologicalweaponsifthey infectand killnativecompetitors.