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(Arslan and Colvin 2002), reflected light, such as normalized difference vegetation index (Basso et al.
2001), and other layers of collectable data. Precision placement of inputs using zone-management maps
created from these layers of data is considered state-of-the-art precision agriculture today (Zhang et al.
2010a). Recently, the use of unmanned aerial vehicles has increased the pace exponentially at which
data can be gathered by the pest management practitioner (Zhang and Kovacs 2012). Site-specific man-
agement is more challenging for insect pests than for soil fertility and weed pests, partially because of
the high cost of obtaining sufficient data to spatially characterize insect populations (Krell et al. 2003).
However, advantages include slowing the development of resistance and preserving natural enemies by
maintaining unsprayed refuges in fields (Karimzadeh et al. 2011). Precision agriculture techniques tar-
geting hemipterans have involved detecting important species or damage indices in data layers involving
soil characteristics or hyperspectral imagery in a limited number of crops, such as cotton (Willers et al.
2005, Reisig and Godfrey 2007, Prabhakar et al. 2011), and suggesting gradient zones of management for
future applications. Recent research incorporating olfactometry into precision agriculture has involved
development of electronic nose (E-nose) technology to detect pests or crop injury. Successful research
with E-nose detection of stink bug injury to cotton (Henderson et al. 2010, Lampson et al. 2014a,b) is
encouraging for future work focusing on localized detection of pests with remote sensing equipment.
16.4.2 Genetically Modified Organisms (GMOs)
The use of genetically modified organisms (GMOs) in commercial agriculture has not been without
controversy regarding misconceptions about health-related concerns (Stewart et al. 2000, Greenwell and
Rughooputh 2004, McHughen and Wager 2010, Ammann 2014) and negative environmental impacts
(Dale et al. 2002). However, the technology has proven to be generally beneficial to the environment by
reducing the volume of foliar-applied insecticides used in the production of major crops, such as corn,
soybeans, and cotton (Phipps and Park 2002, Huang et al. 2003, Benbrook 2012). One risk is the escape
of transgenic crops or crop alleles, which has occurred with herbicide tolerant traits in canola found
in feral populations and in non-transgenic populations (Schafer et al. 2011). However, alleged negative
effects of GMOs on health have not been proven in reputable peer-reviewed research. Therefore, the
benefits of GMO technology are numerous, particularly the segments that confer in-plant protection
from insect pests.
16.4.2.1 Plant-Incorporated Proteins
Genetically modified cotton was made commercially available in 1996 with technology called ‘Bollgard’
cotton by Monsanto Company (Perlak et al. 2001). Genes from the naturally occurring bacterium
Bacillus thuringiensis (Bt) kurstaki that produce proteins specifically toxic to caterpillar pests, were
inserted into the cotton genome, allowing every cell in the transformed cotton plants to produce the same
proteins. Specificity of the toxic proteins to lepidopterans is achieved through unique binding sites on the
midgut epithelial lining of targeted pests. Plant material consumed by caterpillars feeding on Bt cotton
contains the plant-incorporated proteins that bind to these sites after activation by a narrow range of pH
(high – very basic) that also specifically exists in the digestive systems of lepidopterans. Incidentally and
subsequently, the same type of transformations was made with genes that confer resistance to broad-
spectrum herbicides, such as glyphosate (Roundup) (Nida et al. 1996). The in-plant protection from
caterpillar insect pests revolutionized insect management in cotton, and the majority of cotton produced
in the United States contains Bt technology (Williams 2015).
The widespread adoption of Bt cotton for control of major caterpillar pests, such as Heliothis vires-
cens and Helicoverpa zea, did elevate the pest status of hemipteran pests, such as the tarnished plant
bug, Lygus lineolaris, and phytophagous pentatomids because of the reduced use of insecticides in the
crop (Turnipseed et al. 1995, Greene et al. 1999). Because foliar-applied insecticides have not been used
as extensively for control of caterpillar pests in cotton as they were before 1996, coincidental control
of hemipterans, historically considered secondary pests, has been essentially eliminated, allowing true
bugs to become primary pests of the crop. Stink bugs and plant bugs continue to be major pests in Bt
cotton because of the low-insecticide environment, but recent advances with transgenic technology have