426 Invasive Stink Bugs and Related Species (Pentatomoidea)
8.1 Introduction
Piezodorus guildinii (Westwood), commonly known as the redbanded stink bug (United States), the
small green stink bug (Brazil), and the alfalfa stink bug (Argentina), is an important pest of soybean
[Glycine max (L.) Merr.] wherever the crop is grown in warmer regions of the New World (Panizzi and
Slansky 1985a, McPherson and McPherson 2000, Panizzi et al. 2000b), including, more recently, Cuba
(Artabe and Martínez 2003). It also is a pest of other leguminous crops in South America including
alfalfa, Medicago sativa L., and various forage legumes (Quintanilla et al. 1967–1968, Ochoa 1969,
Fraga and Ochoa 1972, Alzugaray and Ribeiro 2000, Ribeiro et al. 2009, Zerbino and Alzugaray 2010,
Zerbino et al. 2015).
Piezodorus guildinii, originally described from material collected on the island of St. Vincent in
the Lesser Antilles in the Caribbean Sea (Westwood 1837, Froeschner 1988), currently ranges from
Argentina and Brazil through Central America to the southern United States (Panizzi and Slansky 1985b,
Panizzi et al. 2000b, Grazia et al. 2015, Panizzi 2015). Its range increased within Brazil in response to
expanded soybean production (Kogan and Turnipseed 1987, Panizzi et al. 2012).
In South America, Piezodorus guildinii first was reported in soybean in Brazil in the early 1970s. Its
distribution followed the great expansion of soybean production during that period, eventually becom-
ing the most important pest of soybean in Brazil (Panizzi and Smith 1976a, Panizzi and Slansky 1985b,
Panizzi et al. 2000b). It also is the most abundant stink bug pest of soybean in Uruguay and Argentina
(Zerbino et al. 2016).
In North America, Piezodorus guildinii first was mentioned as a minor pest of soybean in the Florida
Everglades in the early 1960s (Genung and Green 1962, Genung et al. 1964). Subsequently, Jones and
Sullivan (1982, 1983) and Panizzi and Slansky (1985a) reported it in low numbers in southern South
Carolina and in north central Florida, respectively, in the 1980s. In recent years, it appears to have sud-
denly expanded its range in the United States. However, unlike Brazil, this expansion cannot be attrib-
uted to expanded soybean production (see Section 8.3.2).
8.2 Taxonomy and Identification
8.2.1 Taxonomy
Piezodorus is a predominantly Old World genus with about a dozen valid species worldwide, some of
which are difficult to separate (Leston 1953, Stadden and Ahmad 1995). Nearly half of these species
impact crops (see discussion in Section 8.6.2). These include P. guildinii, the only New World member;
P. hybneri (Gmelin) (= P. rubrofasciatus F.) in Asia and Africa; P. lituratus (F.) in Europe and western
Asia; P. oceanicus (Montrouzier) in Australia; P. punctiventris (Dallas) in West Africa; and P. purus
Stål in sub-Saharan Africa.
Piezodorus guildinii is a member of the hybneri group, which also includes P. hybneri, P. oceanicus,
and P. purus; there have been questions about whether these actually compose different species (Distant
1902, Leston 1953, Staddon and Ahmad 1995). P. guildinii apparently is closely related to P. hybneri
(Staddon and Ahmad 1995) and both share at least one pheromone component (Leal et al. 1998, Borges
et al. 2007, Moraes et al. 2008, Endo et al. 2012). P. oceanicus, the redbanded shield bug, long thought to
be a form of P. hybneri, was described as new (twice), as P. grossi Ahmad (Ahmad 1995) and P. grossi
Staddon (Staddon 1997), before finally being recognized under an earlier described name, P. oceanicus
(Cassis and Gross 2002).
8.2.2 Identification and Comparison with Other Stink Bugs
Piezodorus guildinii (Figure 8.1B,C) is a small pentatomid that often is green with a red band across the
pronotum. It often is confused with other small green-colored stink bugs in North America, especially
the redshouldered stink bug, Thyanta custator accerra McAtee, and other Thyanta spp. These species