746 Invasive Stink Bugs and Related Species (Pentatomoidea)
(Pimentel et al. 2005). Pesticide costs are estimated at $500 million annually in the United States to
control nonindigenous insect species (Pimentel et al. 2005). Quarantine methods can be used to pre-
vent, detect, contain, and eradicate invasive species that may affect humans, animals, plants, and the
natural environment (Mumford 2002). Once an invasive species becomes established, eradication can
be used when the long-term cost of damage, control, or both are expected to exceed the short-term cost
of eradication (Myers et al. 1998). A number of stink bug species have become established outside of
their native distributions. Among these, Nezara viridula is found in Europe, Asia, Australasia, Africa,
and the Americas, but is thought to be native to Africa (Todd 1989; see Chapter 7). Bagrada hilaris is
native to Europe, Africa, and Asia, was found in 2008 in California and since has spread throughout the
southwestern United States (Bundy et al. 2012, Reed et al. 2013; see Chapter 3). Halyomorpha halys,
native to Asia, was found in 1996 in the United States and also has invaded parts of Europe, Australia,
and New Zealand (Rice et al. 2014; see Chapter 4).
16.3.1.4.2 Eradication
Because successful eradication often is achieved when the target pest has a limited distribution, either
through host or habitat specificity or is geographically isolated (Myers et al. 1998), eradication of stink
bugs typically is not possible due to their polyphagous nature and high reproductive ability. Successful
eradication has been achieved with the boll weevil, Anthonomus grandis grandis (Coleoptera:
Curculionidae), in the southeastern United States in cotton by preventing diapause, decreasing reproduc-
tion, and reducing in-season survival by using insecticides and cultural practices (Smith 1998). Another
example of a successful eradication is the tsetse fly, Glossina austeni Newstead, from Unguja Island,
Zanzibar, using the sterile insect technique (Vreyson et al. 2000).
16.3.1.4.3 Certification/Inspections
Preventing the spread of invasive species is more challenging than ever, with on-going changes world-
wide in climate, trade, and travel (Schwalbe and Hallman 2002). As an example of the threat to trade
caused by a species closely related to stink bugs, the kudzu bug, Megacopta cribraria (F.), is native to
Asia and has spread throughout the southern United States. In December 2011, inspectors in Honduras
found two dead kudzu bugs in a shipping container from Georgia. This led to a temporary ban on agri-
cultural shipments from the southern United States until all containers were inspected (Ruberson et al.
2013; see Chapter 5). Efforts in pest survey and detection methods will continue to be crucial in prevent-
ing the establishment of plant pests (McCullough et al. 2006).
16.3.1.5 Chemical Control
Chemical control is the use of natural or synthetic chemicals (pesticides) to reduce pest damage. Within
the framework of integrated pest management of insects, insecticides should largely be reserved for
controlling existing populations that are approaching economically damaging levels. Preventative use
of insecticides generally is discouraged because of the potential for negative non-target impacts. The
point at which an insecticide application can be economically justified is called the economic threshold.
16.3.1.5.1 Economic Injury Levels and Action Thresholds
The Economic Injury Level (EIL) for a given pest in a specific situation is the point where the expected
cost from pest damage is equal to the cost of applying an insecticide to avoid the pest damage. The Action
Threshold (AT), also known as Economic Threshold, Action Level, or simply Threshold, is a point that
occurs before the EIL is reached where action (typically the application of a chemical insecticide) should
be taken to ensure that an increasing pest population will not cause economic damage. To estimate the
current and potential economic cost of an insect population requires (1) an estimate of the size of the
existing pest population, (2) knowledge of the amount of commodity injury caused by a population of
the insect, (3) knowledge of the amount of commodity damage caused by the plant injury observed, and
(4) an estimate of insect population growth rate. Without all these components, an EIL and empirically
based AT cannot be estimated. This practically limits the use of EIL and AT to situations where the pest