748 Invasive Stink Bugs and Related Species (Pentatomoidea)
(1) a broadcast application followed by tillage to incorporate the insecticide, (2) an in-furrow application
where the insecticide is placed near the seed and buried there by the planter, and (3) a seed treatment
where the seed is coated with an insecticide before planting. All three methods are applied before it is
known if there is a problem, so although this is not an ideal situation from an integrated pest management
approach, it is the only chemical control option for certain situations.
The most common method of applying insecticides to above ground pests is by foliar applications.
These sprayers range from backpack single nozzle sprayers to large self-propelled sprayers to airplanes,
but, in all cases, the goal is to apply a uniform layer of insecticide to the target. Insecticide labels, which
accompany all insecticides sold in the United States, provide information on the amount of insecticide
that can be applied legally to control a specific pest. Where possible, these applications should be made
based on monitoring information that indicates that the pest is at an action threshold.
Considerations when making foliar applications should include whether the application needs to be
broadcast over the entire area or whether it can be a spot treatment or banded application. Many insects,
including many stink bugs, concentrate on the edge of a habitat (Tillman et al. 2009, Reay-Jones 2010,
Reay-Jones et al. 2010). As a result, in some situations, an application around the edge of the habitat is
sufficient to manage the pest. For young crops grown in rows, banding the insecticide over the row while
leaving the space between the rows unsprayed is a way to reduce insecticide and environmental costs
without reducing insect control. Another consideration of foliar insecticides is the timing of the applica-
tion. The efficacy of an insecticide can be impacted by the physical environment, namely temperature
(Musser and Shelton 2005, Satpute et al. 2007), time between application and rainfall (Nord and Pepper
1991, Willis et al. 1992), and wind (Smith et al. 2000). The time of application should also consider the
growth stage of the target insect (young immatures are normally the easiest stage to kill), the level of
crop damage, the potential impact on pollinators and other beneficial insects, and other planned crop
production activities (e.g., irrigation, tillage, harvesting).
Regardless of the method or time of application, the goal of chemical control applications is to reduce
insect densities to levels that will not cause economic loss.
16.3.1.6 Biological Control
16.3.1.6.1 Predators
The most important natural enemies of pentatomoids, as with many other insect taxa, are predators,
parasitoids, and pathogens. Most predators of stink bugs are generalists. There are many records of
predaceous pentatomids preying on invasive pentatomoids, but there are no reports that they have had
a significant impact on prey numbers. Vertebrates, especially birds (Exnerová et al. 2003), often have
been mentioned as eating stink bugs including economically important species. Bats have also been
shown to consume pest stink bugs, sometimes in large numbers (e.g., Galorio and Nuñeza 2014). Two
genera of Coccinellidae are specific to Plataspidae (Giorgi et al. 2009). Certain species in the genus
Synona in India are specific to pest plataspids in the genus Coptosoma as well as the invasive kudzu
bug, Megacopta cribraria, and could become candidates for classical biological control of M. cribraria
in the United States (Subramanyam 1925 [cited in Poorani et al. 2008, p. 582]; Afroze and Shuja 1998).
16.3.1.6.2 Parasitoids
Parasitoids are the most effective biotic agents attacking the Pentatomoidea. All pentatomid species
likely are attacked by tachinid flies, and many are attacked by several species, most of which are mem-
bers of the subfamily Phasiinae. Tachinid species, by themselves, generally are not effective agents.
Exceptions are Trichopoda spp. attacking Nezara viridula in the New World, possibly because these are
new associations (Hokkanen and Pimentel 1989). The eggs are the most susceptible stage to parasitoids,
and the genera Trissolcus and Telenomus, within the hymenopterous family Platygastridae, are the most
important worldwide. Species in the families Encyrtidae and Eupelmidae are the next most common
groups of egg parasitoids (Mills 2010). Efficiency of egg mass discovery can be fairly high in crops such
as soybeans (up to 65% or more), with most of the individual eggs in a parasitized mass being attacked
(e.g., Cingolani et al. 2014).