364 Invasive Stink Bugs and Related Species (Pentatomoidea)
Overall, the electronic databases were in agreement with the presence of Nezara viridula in the south-
eastern United States, but all varied on the occurrence of the species in more northern and southwestern
states. Predominant occurrences were in states along the Gulf of Mexico and bordering Mexico as well
as virtually the entire Atlantic seaboard (Figure 7.5). New York is the northernmost occurrence of
N. viridula along the Atlantic seaboard; however, this was an insect detected in a greenhouse environ-
ment (Torre-Bueno 1912). Earlier field surveys did not indicate the presence of N. viridula in New York
(Torre-Bueno 1903, 1908). The westernmost occurrences of N. viridula are California and Washington
(Hoffmann et al. 1987a,b; Discover Life 2015; Anonymous 2016; Looney and Murray 2016), but the
species also was discovered in Hawaii during 1961 (Davis 1964, Nishida 1966, Jones and Caprio 1992).
More recent reports indicate Nezara viridula has been detected in and around Seattle, Washington
(Anonymous 2016, Looney and Murray 2016). Reported occurrences were at locations ranging from
47.20° to 47.62°N (Chris Looney, personal communication). These observations account for the north-
ernmost occurrence in the western United States and lie outside the historically accepted most north-
ern latitudinal boundary of occurrence (i.e., 45°N). The species now has been detected in Seattle for
three consecutive years (beginning in 2014), but the exact origin of the initial infestation is unknown
(Looney and Murray 2016; Chris Looney, personal communication). N. viridula has not been detected
in Oregon, suggesting that the infestation may have resulted from imported plant material (C. Looney,
personal communication) instead of gradual dispersal from California populations. When one consid-
ers all reported occurrences, N. viridula has been recorded from 27 states, over half of the contiguous
United States.
The distribution map does not guarantee that Nezara viridula will be collected every year or through-
out each state (Figure 7.5). In fact, some state records shown in the map may be based on adventitious
specimens, particularly in the northeast. Froeschner (1988) indicated that records from more northern
states “probably are adventitious occurrences.” This is supported by the fact that during the course of a
6-year trapping study for stink bugs in New Jersey, no specimens of N. viridula were collected (Nielsen
et al. 2013). Also supporting this statement is Aldrich (1990) who described a Maryland occurrence as
“adventitious” and likely the result of insect displacement by a hurricane (similar hurricane effects on
N. viridula populations were reported in Texas [Flitters 1963]). A third example of a probable adventi-
tious occurrence was the collection of a third instar by sweeping roadside vegetation in southern Illinois
(McPherson 1982). In addition, a museum specimen was reported that supposedly had been collected in
central Illinois, but there is some question about the accuracy of the label information (McPherson 1982).
FIGURE 7.5 Distribution of Nezara viridula in the United States of America: black represents confirmed field popula-
tions; dark gray represents occurrence based on adventitious individuals, museum specimens, and anecdotal records; and
white represents absence of species. (Map based on data presented in Table 7.2).