Nezara viridula ( L .) 401
proved to be effective for estimating the number of Oebalus pugnax (F.) in grain sorghum (Merchant and
Teetes 1992). Corn is difficult to sample for stink bugs due to its height and the fact that stink bugs tend to
reside in the collar where the leaf connects to the stalk. Therefore, researchers typically use whole plant
visual searches to estimate population density in corn (Tillman 2010, Reisig 2011). Similarly, stink bugs
in vegetable crops are typically scouted based on visual observation (Lye and Story 1989).
Pest managers commonly utilize stink bug-induced damage when making treatment decisions.
Feeding-induced injury symptoms are permanent whereas the presence of the actual bug is ephemeral
or may not be present in the canopy where a sweep net will reach it. For example, Toews et al. (2008)
showed that sampling internal boll injury on developing cotton bolls was 10-fold more sensitive at detect-
ing stink bug infestations compared to use of a sweep net or beat cloth. The spatial dynamics of internal
boll injury relative to captures in a sweep net have been investigated in cotton production (Reay-Jones
et al. 2010). Although considerably less precise, symptoms of external feeding also can be used for
estimating stink bug injury to cotton (Toews et al. 2009, Medrano et al. 2015). Stink bugs form a stylet
sheath when feeding and internal feeding damage is correlated with stylet sheath counts. Apriyanto et al.
(1989) clearly showed that increased numbers of stylet sheaths correlated with observed damage in early
growth corn. Bundy et al. (2000) suggested that a sampling program based on stylet sheath counts could
be developed as a nondestructive sampling tool. Stylet sheaths have been observed and enumerated after
stink bugs have fed on pecan, rice, soybean, and tomato.
7.7.2 Cultural Control
Cultural insect control in agriculture involves the manipulation of standard production practices to
reduce insect populations or make conditions less favorable for establishment and colonization. Many
nonchemical approaches to controlling Nezara viridula have shown promise for reducing populations of
or damage from the species, particularly when used in an integrated pest management program (Knight
and Gurr 2007). When used alone, cultural control methods may be insufficient, but they can be effec-
tive when used in combination or paired with additional strategies such as chemical control, biological
control, or attract-and-kill. Common examples of cultural control include, but are not limited to, manipu-
lation of planting dates, planting density, sanitation, tillage operations, water, nutrients, crop residues,
adjacent habitats, crop rotation, spatial isolation, and harvest timing.
The most studied example of cultural control of stink bugs in the United States is planting date manip-
ulation, but there also are a few publications demonstrating other approaches. In Georgia, Pulakkatu-
Thodi et al. (2014) demonstrated that mean lint yield and economic returns were greater in early-planted
cotton as a result of escaping late summer stink bug pressure. Similarly, in Georgia, Tillman (2010)
observed fewer Nezara viridula in early planted corn. Conversely, most authors find that early-planted
soybean is subject to increased stink bug pressure in the mid-South (Baur et al. 2000) and Southeast
(McPherson et al. 2001). There is some evidence that populations of immature N. viridula may increase
under elevated phosphorus, but no evidence that either potassium or magnesium affects population den-
sity (Funderburk et al. 1991). McPherson and Bondari (1991) observed that there were more stink bugs
in narrow-row planted soybean compared to wide-row plantings. Finally, Buntin et al. (1995) observed
more stink bugs in no-till treatments compared with plow-tillage treatments in soybean.
7.7.3 Biological Control
7.7.3.1 General
There are many known natural enemies of Nezara viridula. Parasitoids are the most important (Chapter
17 ). Jones (1988) listed 57 species among two families of Diptera and five families of Hymenoptera, with
41 of these species parasitizing the egg stage. Only a few species appeared to be well-adapted or of signifi-
cant importance. Although no hyperparasitoids were reported, Clarke and Seymour (1992) subsequently
reported two species of Acroclisoides (Hymenoptera: Pteromalidae) attacking N. viridula eggs previously
attacked by Trissolcus basalis (Wollaston) (Hymenoptera: Platygastridae) in Australia. Recent studies
showed that Ooencyrtus telenomicida Vassiliev (Hymenoptera: Encyrtidae) is a facultative hyperparasitod