Planting Sentinel European Trees in Eastern Asia as a Novel Method to Identify Potential Insect Pest Invaders

Abstract

Quarantine measures to prevent insect invasions tend to focus on well-known pests but a large proportion of the recent invaders were not known to cause significant damage in their native range, or were not even known to science before their introduction. A novel method is proposed to detect new potential pests of woody plants in their region of origin before they are introduced to a new continent. Since Asia is currently considered to be the main supplier of insect invaders to Europe, sentinel trees were planted in China during 2007-2011 as an early warning tool to identify the potential for additional Asian insect species to colonize European trees. Seedlings (1-1.5 m tall) of five broadleaved (Quercus petraea, Q. suber, Q. ilex, Fagus sylvatica, and Carpinus betulus) and two conifer species (Abies alba and Cupressus sempervirens) were planted in blocks of 100 seedlings at two widely separated sites (one in a nursery near Beijing and the other in a forest environment near Fuyang in eastern China), and then regularly surveyed for colonization by insects. A total of 104 insect species, mostly defoliators, were observed on these new hosts, and at least six species were capable of larval development. Although a number of the insects observed were probably incidental feeders, 38 species had more than five colonization events, mostly infesting Q. petraea, and could be considered as being capable of switching to European trees if introduced to Europe. Three years was shown to be an appropriate duration for the experiment, since the rate of colonization then tended to plateau. A majority of the identified species appeared to have switched from agricultural crops and fruit trees rather than from forest trees. Although these results are promising, the method is not appropriate for xylophagous pests and other groups developing on larger trees. Apart from the logistical problems, the identification to species level of the specimens collected was a major difficulty. This situation could be improved by the development of molecular databases.

EU Legislation on Forest Plant Health: an Overview with a Focus on <em>Fusarium Circinatum</em>

“…Nonetheless, many newnon-native pests were previously unknown to be harmful, or even to science, and were therefore not regulated before they invaded. To address this issue, monitoring of sentinel plants in exporting countries has been proposed as a valuable tool to identify harmful organisms prior to their arrival [72,73,74]. Although several European projects (e.g.…”

Spotting the pests of tomorrow—Sampling designs for detection of species associations with woody plants

“…This is exemplified by differences between two sentinel plantings in China. The first was located in an intensively managed agricultural area and the insects found on the trees were mainly insects found in agricultural land (Roques et al, ). Application of fertilizers including macronutrients, primarily nitrogen, generally decrease fungal species diversity and may cause shifts in community structures (i.e.…”

Forest pests and their management in the Anthropocene

“…For example, ports of entry with diploxylon pines in the area are especially vulnerable to introductions of potential pests that feed on hard pines. Sentinel tree nurseries can be used as a tool for identifying potentially dangerous pests before they have been accidentally introduced to a region with vulnerable tree species (Roques et al 2015). In the Anthropocene, programs to prevent new pest introductions should take into account that ports of entry that were previously too cold for pest X may now be climatically suitable (T-9) (Weed et al 2013).…”