Search

The unintentional transport of insects beyond their native ranges has greatly increased with globalization over the past century, leading to higher propagule pressure in non-native ranges of many species. Knowledge about the prevalence of a species in international invasion pathways is important for predicting invasions and taking appropriate biosecurity measures. We investigated the spatiotemporal patterns and drivers of interceptions—detections of at least one individual with imported goods that potentially serve as a proxy for arrival rates—for a tree-killing bark beetle, the European spruce bark beetle (Ips typographus L.; Coleoptera: Curculionidae: Scolytinae), in the USA from 1914 to 2008. Across the study period, there were 505 interceptions of I. typographus with shipments originating from > 25 countries at ports in 22 US states. Interceptions first occurred in 1938, peaked at 33 and 25 in 1984 and 1996, respectively, and declined after the mid-1990s. Interceptions of I. typographus did not have a statistically detectable relationship with outbreak levels in the native range, were inversely related to annual import volume (an artifact likely driven by changes in inspection policies), and were more frequent during the winter. Thus, while interceptions of I. typographus are challenging to predict, we found evidence that (i) biosecurity practices against this beetle could be increased during winter but not in response to outbreaks in source regions and (ii) the overall abundance of this beetle in invasion pathways has recently decreased, probably because strengthened phytosanitary protocols have reduced contamination levels and/or decreased the perceived need for inspections. [ABSTRACT FROM AUTHOR]

Two Asian longhorn beetles, Anoplophora glabripennis and Anoplophora chinensis, are among the most serious alien invasive species attacking forest and urban trees, both in North America and Europe. Major efforts have been put into preventing further entry and establishment of the two species as well as promoting their successful eradication. Here, we review these efforts, their progress and outcome, and scientific advancements in monitoring and control methods. The combined international activities and harmonizing legislative changes in detection and eradication methods have proven worthwhile, with more than 45% of eradication programmes successful in the last 12 years. Some countries were able to completely eradicate all populations and others managed to reduce the area affected. Although the costs of the eradication programmes can be very high, the benefits outweigh inaction. Attempts to eradicate A. chinensis have been more challenging in comparison with those targeting A. glabripennis. For both species, efforts are hampered by the ongoing arrival of new beetles, both from their native regions in Asia and from other invaded regions via bridgehead effects. The methods used for eradication have not changed much during the last decade, and host removal is still the method most commonly used. On the other hand, detection methods have diversified during the last decade with advances in semiochemical research and use of detection dogs. The next decade will determine if eradications continue to be successful, particularly in the case of A. chinensis, which has been targeted in some countries for containment instead of eradication. [ABSTRACT FROM AUTHOR]

The brown marmorated stink bug, Halyomorpha halys, is an agricultural and urban pest that has become widely established as an invasive species of major concern in the USA and throughout Europe. The insect forms large aggregations before entering diapause, and it is often these aggregations that are found by biosecurity officials conducting inspections of internationally shipped freight. Here, we aimed to gain insights into the potential volatile emissions, mobility, and mortality rates of the insects after undergoing a ship voyage across the equator (i.e. from northern hemisphere winter to southern hemisphere summer). Experiments were performed to simulate the effects on aggregations of diapausing H. halys of two variables associated with trans-Pacific voyages, i.e. ship and container movement and temperature changes within containers. Thus, H. halys aggregations were exposed to simulated shipping movement, using a 6-axis VS-6577G-B Denso robot arm, and emission of defence volatiles was measured repeatedly during the "voyage." We also simulated temperature changes as they occur during a 26-day voyage from Baltimore, northeast USA, to Auckland, New Zealand, and assessed the effects on the mortality and mobility of the bugs. Aggregations that experienced movement were not found to be any more likely to release volatiles than stationary aggregations and neither did the movement affect bug mobility. Temperature changes had a significant effect on mobility. However, towards the end of the temperature simulation, most H. halys had died, probably from a lack of food and moisture. These findings are highly relevant for border biosecurity risk assessment and pathway risk management. [ABSTRACT FROM AUTHOR]

International trade and movement of people are largely responsible for increasing numbers of non-native insect introductions to new environments. For forest insects, trade in live plants and transport of wood packaging material (WPM) are considered the most important pathways facilitating long-distance invasions. These two pathways as well as trade in firewood, logs, and processed wood are commonly associated with insect infestations, while "hitchhiking" insects can be moved on cargo, in the conveyances used for transport (e.g., containers, ships), or associated with international movement of passengers and mail. Once established in a new country, insects can spread domestically through all of the above pathways. Considerable national and international efforts have been made in recent years to reduce the risk of international movement of plant pests. International Standards for Phytosanitary Measures (ISPMs) No. 15 (WPM), 36 (plants for planting), and 39 (wood) are examples of phytosanitary standards that have been adopted by the International Plant Protection Convention to reduce risks of invasions of forest pests. The implementation of ISPMs by exporting countries is expected to reduce the arrival rate and establishments of new forest pests. However, many challenges remain to reduce pest transportation through international trade, given the ever-increasing volume of traded goods, variations in quarantine procedures between countries, and rapid changes in distribution networks. It is therefore likely that many more human-assisted invasions of forest insects will take place. New geographic expansions by natural modes are also made possible due to changes in host distribution and/or climate. [ABSTRACT FROM AUTHOR]