General Insect Management 743
United States in 1959 (Meadows 1985). Ionizing radiation was used to kill or render nymphs of Nezara
viridula sterile (Dyby and Sailer 1999). It was hoped that sterile individuals would promote autocidal
control for the species after release of semisterile populations (Knipling 1969), but the results were
limited.
16.3.1.2.4 Temperature
Temperature is the most important environmental factor for insects. Because most insects are ectother-
mic or poikilothermic, their life processes are affected by temperature. The general effects of tempera-
ture on insect physiology, behavior, and development were reviewed by Wigglesworth (1972). As climate
change becomes more apparent, any rise in average global temperature undoubtedly will affect insects,
and heteropterans will be no exception (Musolin 2007, Musolin et al. 2010). The influence of tempera-
ture on pentatomids has been studied, with most research focused on the impacts of temperature on rates
of development of the insect (Ali and Ewiess 1977, Naresh and Smith 1983, Simmons and Yeargan 1988,
Kotaki 1998, Musolin and Numata 2003). However, mutualistic gut-associated symbionts of stink bugs
also can be affected negatively by temperature (Prado et al. 2010). Although few studies have addressed
manipulations of temperature to manage hemipterans as pests of field crops, there are numerous appli-
cations for the strategy regarding insect and mite pests of stored products (Fields 1992). In a review of
over 50 published papers on the effects of temperature on pests of stored products, the optimal range for
growth and reproduction for stored-product insects and mites was defined as 25–33°C, with an extended
range of 13–35°C acceptable for most development and reproduction, and <13 or >35°C eventually being
lethal (Fields 1992). Heat treatments, increasing the ambient temperature to 50–60°C for a 24–36 hour
period, are a widely used alternative to methyl bromide gas for management of stored product insects in
food processing facilities (Mahroof et al. 2005). In response to rapid heating, studies show that the red
flour beetle, Tribolium castaneum Herbst, produces heat-inducible proteins that confer theromotolerance
(Mahroof et al. 2005). Heat treatments also are a residue-free management method for the bed bug,
Cimex lectularius L., in residential spaces (Kells and Goblirsch 2011). Forced hot air has been used for
quarantine treatments, such as West Indian fruit fly, Anastrepha obliqua (Macquart), on mango (Mangan
and Ingle 1992).
16.3.1.2.5 Physical Barriers
Numerous types of physical barriers have been used to successfully control insects, and many of those
methods for agriculturally important insects have been reviewed (Boiteau and Vernon 2001, Vincent
et al. 2003). Trenches (Boiteau and Osborn 1999), fences (Bomford et al. 2000), mulches (Brust 1994),
particle films (Glenn et al. 1999, Puterka et al. 2000), traps (Cohen and Yuval 2000), flooding (Averill
et al. 1997), screening (Dobson 2015), barriers (Tillman 2014, Tillman et al. 2015), and various other
physical control techniques have been used to control or deter insects. Materials that block UV light have
been used to protect greenhouse crops from insect vectors of plant diseases (Diaz and Fereres 2007) by
interfering with the vision of insects and limiting their ability to locate host plants. Although considered
a cultural control strategy, trap cropping has been tested as a barrier strategy to concentrate pestiferous
insects in a small area adjacent to the crop of main interest where they can be destroyed or held, preserv-
ing the protected commodity (Todd and Schumann 1988). This was shown to be unreliable for stink bugs
in early season soybean production systems (Smith et al. 2009) that dominate most of the mid-southern
United States. In other studies, the limitations and advantages of using trap cropping strategies for stink
bugs were described (Mizell et al. 2008). Successful use of soybeans as a trap crop for protecting cot-
ton was reported recently by Tillman et al. (2015). Use of a synthetic (1.83 m high black, polypropylene
sheeting) physical barrier between peanuts and cotton did show promise in protecting cotton from stink
bugs (Tillman et al. 2015) as did plantings of grain sorghum (Tillman 2014).
16.3.1.2.6 Hand Removal (Handpicking)
Manual removal of arthropod pests from undesired locations is a practice that dates back to ancient
times. Removing parasites from animals, including humans, by hand was the original control tactic for
pest control. This practice extended to plants of interest, including those that were cultivated. During