428 Invasive Stink Bugs and Related Species (Pentatomoidea)
8.3.1 Range Expansion in South America
The growth of agribusiness in the Neotropics in recent years has been dramatic. For example, in Brazil
alone, soybean production increased 10-fold from 1960 to 1973 (Turnipseed and Kogan 1976). Production
increased from 15.5 million tons in 1980 to about 97 million tons in 2016 (Anonymous 2016). A similar
situation occurred in other countries such as Argentina and Paraguay. Under such dramatic ecosystem
reformations via displacement of other crop and non-crop areas, changes in pest status of insects can be
dramatic (Turnipseed 1973, Panizzi et al. 2012).
Much research has been conducted on pest pentatomids in South America because of their long his-
tory as soybean pests (Panizzi and Slansky 1985b; Panizzi et al. 2000b, 2012). Piezodorus guildinii
seldom was seen in soybean in Brazil until the early 1970s (Panizzi et al. 2000b). As soybean cultivation
expanded to the central, western, and northeastern parts of Brazil, this insect eventually became the most
important soybean pest in that country.
During this great expansion of soybean cultivation in South America, Nezara viridula (L.) and
Piezodorus guildinii were the dominant phytophagous stink bugs in soybean in Argentina (Vicentini and
Jimenez 1977) and in southern Brazil (Kogan 1977). In Uruguay, P. guildinii first was observed on soy-
bean in 1969 but was not considered a pest until 1981 (Bourokhovitch and Morey 1981, Gonnet 2007).
It is now one of the primary pests of agricultural-pastoral production systems in Uruguay (Castiglioni
2004, Zerbino et al. 2016).
Beginning in the late 1970s, Piezodorus guildinii began to replace Nezara viridula as the dominant
pest of soybean in some areas of Brazil (Panizzi et al. 1977, Panizzi 1985a, Panizzi and Slansky 1985b).
As a smaller and more mobile pentatomid, P. guildinii apparently is better adapted to warmer climates
than N. viridula and also seems to be more capable of colonizing soybean in Brazil early in the season
(Panizzi and Smith 1976a, Heinrichs 1976, Panizzi 1985a). However, the reasons for this apparent spe-
cies shift are not completely clear. In addition to mobility and early colonization of the crop, such factors
as lower rates of parasitism and differential susceptibility to insecticides may be involved (Kogan and
Turnipseed 1987). Direct seeding, changes in planting dates, and the use of early maturing varieties also
may have contributed to the changing importance of pests.
8.3.2 Range Expansion in North America
Soybean production in the United States doubled from 1960 to 1973, with the greatest rate of increase in
the southeastern states (Turnipseed and Kogan 1976). In 10 southern states, soybean production tripled
to 6.5 million hectares while in the original production areas in Corn Belt states, production increased
by 47% to 13.3 million hectares. Following the expansion of soybean cultivation in the southern states,
a complex of stink bugs soon became a major factor in limiting yields from South Carolina to East Texas.
They accounted for “more than $68 million in losses some years in the southern states from insecticide
costs and crop damage” (McPherson et al. 1994).
The most common species in the stink bug complex for soybean in the United States typically have been
the southern green stink bug, Nezara viridula; green stink bug, Chinavia hilaris (Say) [previously reported
as Acrosternum hilare (Say)]; and brown stink bug, Euschistus servus (Say) (Miner 1966; Turnipseed 1972,
1973; Carner et al. 1974; Jones and Sullivan 1983; McPherson et al. 1993, 1994; Funderburk et al. 1999; Baur
et al. 2000; Gore et al. 2006). Other minor species of phytophagous stink bugs often mentioned in soybean
include other Euschistus spp. and Thyanta spp., plus several more for which soybean probably is not a devel-
opmental host. The minor species vary with geography. Jones and Sullivan (1983) is the only one of the earlier
reports mentioning Piezodorus guildinii (in small numbers) in southern South Carolina in the early 1980s.
Although first mentioned as a pest in south Florida (Genung and Green 1962), Piezodorus guildinii
probably has existed in peninsular Florida and Mexico as a long-term resident, breeding on native
legumes such as indigo (Indigofera spp.) and clovers (Trifolium spp.) (Panizzi and Slansky 1985a,b). As
with Nezara viridula, cold winters likely limit its northern boundaries in the United States (Jones and
Sullivan 1981), but it is capable of expanding northward again following mild winters (Musolin 2007).
In 2008, in Mississippi, yield loss and control costs due to stink bugs was estimated to be $29.8 million
with P. guildinii being the most abundant species (Musser et al. 2009).