Pearson Dean E, Callaway Ragan M
Ecol Lett. 2006 Apr;9(4):443-50. doi: 10.1111/j.1461-0248.2006.00896.x.
Biological control of exotic invasive plants using exotic insects is practiced under the assumption that biological control agents are safe if they do not directly attack non-target species. We tested this assumption by evaluating the potential for two host-specific biological control agents (Urophora spp.), widely established in North America for spotted knapweed (Centaurea maculosa) control, to indirectly elevate Sin Nombre hantavirus by providing food subsidies to populations of deer mice (Peromyscus maniculatus), the primary reservoir for the virus. We show that seropositive deer mice (mice testing positive for hantavirus) were over three times more abundant in the presence of the biocontrol food subsidy. Elevating densities of seropositive mice may increase risk of hantavirus infection in humans and significantly alter hantavirus ecology. Host specificity alone does not ensure safe biological control. To minimize indirect risks to non-target species, biological control agents must suppress pest populations enough to reduce their own numbers.
利用外来昆虫对入侵性外来植物进行生物防治，是基于这样一种假设：如果生物防治剂不直接攻击非目标物种，那么它们就是安全的。我们通过评估两种宿主特异性生物防治剂（兔耳菊实蝇属）的潜在影响，来检验这一假设。这两种生物防治剂在北美广泛用于控制斑点矢车菊，它们会通过为鹿鼠（白足鼠）种群提供食物补贴，间接提高辛诺柏汉坦病毒的传播几率，而鹿鼠是该病毒的主要宿主。我们发现，在有生物防治食物补贴的情况下，血清阳性的鹿鼠（检测出汉坦病毒呈阳性的小鼠）数量是原来的三倍多。血清阳性小鼠数量的增加可能会增加人类感染汉坦病毒的风险，并显著改变汉坦病毒的生态环境。仅靠宿主特异性并不能确保生物防治的安全性。为了将对非目标物种的间接风险降至最低，生物防治剂必须充分抑制害虫种群数量，以减少自身数量。
