Halyomorpha halys (Stål) 259
instars walking significantly greater horizontal distances than other life stages and third and fourth
instars climbing significantly longer distances than second instars and adults (Lee et al. 2014b). In the
same study, Lee et al. (2014b) demonstrated under field conditions that fifth instars walked across turf
nearly twice the distance traveled by third instars. Acebes-Doria et al. (2017) demonstrated that nymphs
moved up and down hosts and that movement varied between different hosts. They also showed that
movement of early and older instars was dependent on the time of the year.
Movement of Halyomorpha halys between host plants has been shown by Nielsen and Hamilton
(2009b) to be related to time of year, host maturity, and distance between hosts. They followed the
abundance of H. halys on eleven fruit and ornamental hosts and showed that there were significant differ-
ences in abundance of nymphs and adults on each host depending on whether or not samples were taken
in early, mid-, and late season and related these differences to the presence of fruit. The impact of the
presence of fruit in ornamental nurseries on populations of H. halys has been investigated by Martinson
et al. (2015). In their study of 3,844 trees across 223 cultivars, they demonstrated the presence of fruit
was a good predictor of adult and nymphal seasonal abundance and within-tree distribution. They also
showed that the removal of fruit suppressed the presence of H. halys adults and nymphs. Venugopal et al.
(2015a,b) showed plant maturity to be an important indicator of H. halys presence within corn and soy-
bean fields and between adjacent fields of corn and soybean. They also showed in woody plant nurseries
that the distance from a bordering field of corn or soybeans or from a residential area influenced H. halys
abundance as they moved from the exterior to the interior of the nursery planting.
4.4.7 Spatial and Nutritional Attributes in Relation to Halyomorpha halys Movement
Spatial attributes affecting the large-scale (i.e., state, nation, and world) movement, distribution, and
potential range of Halyomorpha halys include annual mean temperature, maximum temperature of the
warmest month, minimum temperature of the coldest month, annual precipitation, annual mean radia-
tion, wetland rights-of-way, urban developments, railroads, and elevation (Zhu et al. 2012, Wallner et al.
2014); more detailed information can be found in Section 4.4.8 of this chapter by Wenjun Bu. This sec-
tion delineates spatial attributes in relation to movement of H. halys in agricultural landscapes including
overwintering sites, surrounding vegetation, host plants, agricultural practices such as pest management
and intercropping, and land-use types.
4.4.7.1 General Movement Patterns of Halyomorpha halys in Agricultural Landscapes
Halyomorpha halys is highly mobile, has a wide host range, and occupies a large geographic area.
Therefore, it can utilize various resources in and around cropping areas throughout the year by movement
to find the best or temporally available resources such as food, shelter, and oviposition sites. Movement of
H. halys begins when adults emerge from overwintering sites in early spring. Then, they feed on various
plants including crops and reproduce throughout the crop-growing season. H. halys also has been shown
to move within a crop during the growing season. Hahn et al. (2017) showed that early in the season,
H. halys did not exhibit clustering early in the season. However, as the crop matured, H. halys clustered
in areas with ripe fruit. Rice et al. (2016) examined the influence of landscape features surrounding
processing tomato fields on H. halys damage and demonstrated that the size and shape of the forests bor-
dering processing tomato fields and geographic location impacted damage. They found that large areas
of woods bordering the fields in southern areas of the mid-Atlantic had higher levels of damage. When
temperatures decrease below 15°C in autumn (Watanabe et al. 1994), they return to overwintering sites.
Therefore, knowledge of spatial arrangement of crops, surrounding vegetation, and overwintering sites
is key to developing management tactics to effectively control H. halys.
4.4.7.2 Spatial Attributes Associated with Movement
from Overwintering Sites to Surrounding Vegetation
Halyomorpha halys adults overwinter in the wild (e.g., under bark, in crevices of rocks) or in human-
made structures (e.g., sheds, barns, houses). In early spring, they emerge from overwintering sites.