316 Invasive Stink Bugs and Related Species (Pentatomoidea)
gutters, whereas the two rates (0.10 and 0.30%) of dinotefuran were statistically (P ≥ .05) similar on 15
of 16 sampling dates.
The rapid knockdown of Megacopta cribraria following exposure to residuals of the neonicotinoid
dinotefuran suggests high sensitivity to this insecticide. In their study (Seiter et al. 2013b) the rapid
knockdown of M. cribraria by dinotefuran probably was masked by the design of their assay. Adults
were under constant exposure to residual deposits of each product. The earliest data presented from their
study is from 2 hours of constant exposure. Exposure of M. cribraria to a 1-day-old residual of dinote-
furan on metal resulted in 100% mortality after 2 hours. In a similar study (Dan R. Suiter, unpublished
data), dinotefuran killed 100% of exposed M. cribraria after 1 hour of forced exposure.
Clearly, there are several insecticides that are effective against Megacopta cribraria, but they are not
equal in initial knockdown or in residual efficacy. Although efficacy is important, regulatory issues and
product labeling may limit insecticide availability and determine which insecticides are available for use
outdoors on structures or nearby host plants.
5.6.2 Crop Pest
5.6.2.1 Pest Status on Crops
In the Old World, Megacopta cribraria is a pest of numerous legume crops. In India and Pakistan, it has
been reported to be an important pest of lablab bean, hence the common name ‘lablab bug’ (Ahmad and
Moizuddin 1975a,b; Chandra and Kushwaha 2013; Thippeswamy and Rajagopal 1998a,b). However, tri-
als with the introduced population in the southeastern United States found that this bug did not survive to
adulthood on lablab bean (Zhang et al. 2012, Medal et al. 2013b, Blount et al. 2015). In India, it has been
listed as a pest of agathi, leguminous vegetable crops including mung bean , pigeon pea, urd bean [Vigna
mungo (L.) Hepper], and velvet bean [Mucuna pruriens (L.) DC.] (Ramakrisha Ayyar 1920; Shroff
1920; Fletcher 1921; Lal 1980, 1985; Borah and Dutta 2002; Rani and Sridhar 2004; Thippeswamy and
Rajagopal 2005b; Borah and Sarma 2009a,b). It is also a reported pest of lima bean in China (Hoffmann
1931) and kidney bean (Phaseolus vulgaris L.) in Japan (Ishihara 1950, Ren 1984).
Megacopta cribraria is an agriculturally important pest of soybeans in both its native range (Wang et
al. 1996, Zhixing et al. 1996, Wu et al. 2006, Hosokawa et al. 2007b, Sujithra et al. 2008) and the United
States (Greene et al. 2012; Seiter et al. 2013a,c; Roberts et al. 2014). Thippeswamy and Rajagopal (2005a)
reported that feeding on leaves, shoots, and young pods led to “crinkled” leaves, although the effects
on yield were not quantified. Likewise, Kikuchi and Kobayashi (2010) showed a reduction in growth
of the main stem and in the number of trifoliates produced, as well as delayed growth, when soybeans
were subjected to feeding by adults exceeding 40 individuals per plant; however, they did not quantify
yield losses. Zhixing et al. (1996) showed yield losses exceeding 50% after exposure to M. cribraria at
high densities (reported as 80 per “bunch”). Similar results were observed in soybeans in China, where
yield losses up to 50% were reported (Wang et al. 1996). Yield loss in soybean has been documented
in the United States when large numbers of bugs were left untreated. Seiter et al. (2013a) reported yield
losses of about 60% in cage trials with initial infestation densities of 25 adults per plant; the yield com-
ponents of seeds per pod and individual seed weight were reduced as initial densities of M. cribraria (0,
5, and 25 per plant) increased in this study. Roberts et al. (2014) reported an average yield loss of 19%,
with a range from 0 to 60%, from untreated plots compared with protected plots in 37 trials conducted
in Georgia from 2010 to 2013. In North Carolina, plots protected with bifenthrin had 56% fewer bugs
and 6% higher yields compared to unsprayed plots (Del Pozo-Valdivia et al. 2017). Blount et al. (2016)
reported that early planted soybeans (April, May, June) are more at risk for yield loss due to this insect
than are later planted soybeans. In the southern United States, 6,070 hectares were infested with M.
cribraria in 2011 and the economic impact (crop loss + cost of control) of this pest in soybeans was esti-
mated to be US $76,000.00 (Musser et al. 2012). The number of hectares infested increased to 148,358
in 2012, 233,434 in 2013, and 359,835 in 2014 (Musser et al. 2013, 2014, 2015) resulting in an economic
impact of US $988,034.00, $4,286,107.00, and $1,383,221.00, respectively. The reduction in economic
impact in 2014 probably was due to a reduced number of bugs following a particularly cold winter of
2013 –2014.