Nezara viridula ( L .) 397
kurstaki) when flowers and bolls were forming. Additionally, the planting date of a particular agronomic
crop has a profound impact on its host suitability to stink bugs. For example, Tillman (2010) observed
greater populations of Euschistus servus (Say) (brown stink bug) and N. viridula in late-planted com-
pared to early-planted corn. Understanding these movements and being able to predict when the popula-
tion is likely to disperse and colonize new habitats is important for formulating management strategies.
Direct empirical evidence on stink bug dispersal is limited. However, stink bugs are widely regarded
as strong fliers based on their ability to find and colonize susceptible agronomic crops that are isolated
spatially in the landscape. Tillman et al. (2009) showed that an individual stink bug could be recaptured
as far as 120 meters from the release site. Huang (2012) showed that marked stink bugs were much more
likely to be recovered only a few meters from where they were marked in agronomic crops. A tethered
stink bug, Graphosoma rubrolineatum (Westwood), was estimated to fly a distance of over 27 kilometers
in a single 7-hour flight (Cui and Cai 2008), indicating that stink bugs are capable of long-distance flights.
However, focusing on the individual as opposed to populations may oversimplify the importance of local
dispersal, largely because increased dispersal distance tends to dilute the population in a particular space.
A mosaic of ecosystems comprises the broad concept embodied by the term landscape. In comparison,
the spatial arrangement of resource patches utilized by a species comprises what Ehler (2000) termed
the farmscape. Movement between hosts can be described at the farm (proximate) or landscape (distant)
level, and the scale at which stink bugs function in those environments depends upon numerous factors
related to the temporal and spatial availability of suitable hosts (Kennedy and Storer 2000, Reeves et al.
2010). At the farmscape level, stink bugs move from a field of one host to an adjacent field when the adja-
cent host become equally or more attractive through time (Pilkay et al. 2015). Stink bugs are extremely
polyphagous (see Tables 7.4 and 7.5) and prefer plants with developing seeds as hosts (Jones and Sullivan
1982). Consequently, they must move, and those movements can be proximate (Kareiva 1983) if the local
environment supports suitable hosts, or they can be distant into the landscape if acceptable hosts are not
present locally. Stink bugs are capable of short or long flights, but tendency for longer flights changes over
the season, peaking near the end of the summer months for Halyomorpha halys (Stål) (brown marmorated
stink bug) (Wiman et al. 2015). Populations of stink bugs have been observed in mass flights (Wilbur
1939), and multiple species have been trapped in seasonal synchronous flights (Cherry and Wilson 2011).
Movement and subsequent settling of Nezara viridula is associated with location and quality of hosts
(Velasco and Walter 1993, Herbert and Toews 2012), selection of mates (Borges et al. 1987), diapause,
and overwintering (Musolin and Numata 2003b, Musolin 2012), and various abiotic factors drive these
activities (Gu and Walter 1989, Todd 1989). Research indicates that stink bugs tend to aggregate near
the edges of fields including cotton (Toews and Shurley 2009), corn, wheat (Reisig 2011), soybean
(Venugopal et al. 2014), and peanut (Tillman et al. 2009). Soybean is an extremely suitable host plant
for pentatomids, especially N. viridula (Velasco and Walter 1992, McPherson et al. 1993, Smith et al.
2008, Olson et al. 2011, Pilkay et al. 2015), so the species can be observed readily on the host within its
worldwide distribution (Todd 1989, Clarke 1992, Vivan and Panizzi 2006). Movement at the farm level
within soybeans has been studied across production systems (i.e., maturity groups, host phenology, and
planting dates) (Schumann and Todd 1982, Smith et al. 2009), and limited movement by nymphs of N.
viridula and Piezodorus guildinii (Westwood) has been measured in the crop (Panizzi et al. 1980). Wild
hosts of N. viridula and other stink bugs also are important (Tables 7.4 and 7.5; Jones and Sullivan 1982,
Panizzi 1997, Olson et al. 2012) and support movement of species at the farm and landscape level through
temporal and spatial availability.
In addition to host quality, stink bug movement and intraspecific communication is influenced by
pheromones and substrate-borne vibrational cues. Male-produced stink bug pheromone components
have been identified from multiple sexually mature stink bug species that attract conspecific females,
males, and even a few late instars (Mitchell and Mau 1971, Harris and Todd 1980, Tillman et al. 2010)
(see Chapter 15). Although the exact ratio differs by species, both Chinavia hilaris and Nezara viridula
males produce cis-and trans-(Z)-bisabolene epoxide blends (Aldrich 1988; Aldrich et al. 1987, 1989,
1993). Synthetic pheromone lures can be used to attract stink bugs to traps (Tillman et al. 2010), but
stink bugs are relatively weakly attracted to pheromone-baited traps compared to the strong attraction
exhibited by lepidopteran species to similar traps. This is likely because stink bugs are long-lived and
can oviposit for several weeks as opposed to only a few days in Lepidoptera. Muted (= reduced) capture