370 Invasive Stink Bugs and Related Species (Pentatomoidea)
Nilaparvata lugens Stål (Hemiptera: Delphacidae). Interestingly, Malouf (1933) also reported rod-like
bacteria in the ectodermal sac of males, hypothesizing that males transferred these bacteria to females
during mating. Fortes (2010) similarly “verified a rich diversity of bacteria associated with the male
reproductive system of Nezara viridula, with predominance of the Enterobacteriaceae Klebsiella sp.,
which was previously reported associated with the gut of N. viridula.” Prado et al. (2006) also identified
a Enterobacteriaceae bacterium in the gut of N. viridula, adding that localization of the bacterium within
the gut varied between adults and nymphs. Although Glasgow (1914) suggested transovarial transmis-
sion, Prado et al. (2006) indicated, instead, that oral transmission was responsible for transfer of symbi-
onts to newly eclosed insects.
Some species transfer endosymbionts via bacteria-filled capsules laid underneath eggs and subse-
quently utilized by newly eclosed nymphs (Fukatsu and Hosokawa 2002). Ovipositing Nezara viridula
females, however, smear the surfaces of eggs with viscous material (Drake 1920), depositing beneficial
bacteria on the egg surface (Prado et al. 2006). However, it is unclear whether the viscous substance has
been studied closely to determine whether the endosymbionts are, in fact, included in the viscous sub-
stance. That is, anatomically, the ovipositor and the rectum are in close proximity, and bacteria have been
shown to be present in bug feces. Is it possible that the eggs are passively contaminated with bacteria due
to this proximity? Alternatively, if the smeared material is the sole source of egg contamination, should
we see a gland that provides a constant supply of viscous material infected with bacteria? Regardless,
the egg surfaces subsequently are probed by newly hatched instars that acquire these endosymbionts for
their own development. Sterilization of egg surfaces or gut resulted in compromised fitness (Hirose et
al. 2006, Prado et al. 2009, Tada et al. 2011), thereby demonstrating the crucial role of endosymbionts in
the biology of N. viridula.
Other microorganisms also are present in Nezara viridula (Ragsdale et al. 1979, Hirose et al. 2006).
Esquivel and Medrano (2012) demonstrated that ingested bacteria seemingly colonize selective regions
of the digestive system preferentially, resulting in transmission of those bacteria colonizing the ros-
trum and head (salivary canals). That is, although Pantoea agglomerans, Pantoea ananatis (Ser ra no),
Klebsiella pneumoniae (Schroeter), and Nematospora coryli Peglion were ingested, only P. agglomer-
ans and N. coryli were transmitted to cotton bolls. These latter two species also were the only microbes
detected in the rostrum, head, and the alimentary canal. K. pneumoniae and P. ananatis were detected in
the alimentary canal but not in the rostrum and head. The latter organism (i.e., P. ananatis) also occurs
in, and is readily transmitted by, the cotton fleahopper [Pseudatomoscelis seriatus (Reuter) (Miridae)].
This raises the question whether the microenvironment (e.g., pH in salivary glands/system, temperature)
of N. viridula is affecting colonization and transmission of P. ananatis. Further, if this is the case, and if
we can elucidate the mechanism, can we affect the mechanism such that we can prevent N. viridula from
transmitting other pathogenic organisms? On the related issue of affecting mechanisms, identification of
neuropeptides to affect water balance to disrupt physiological processes may hold promise for managing
populations (Predel et al. 2008).
7.4.3 Mate Selection
Larger females of Nezara viridula prefer to mate with larger males (McLain 1980). Mitchell and Mau
(1969) describe the courtship process. Briefly, males initiate mating beginning with attempts (using
their head) to raise the female’s terminal abdominal segments so that the male can move into position
to engage their respective genitalia. Once engaged (in copula), the insects face away from each other
and can remain in copula “for a few minutes to several days,” in some cases 10 days (Figure 7.1C;
Mitchell and Mau 1969). Similarly, Harris and Todd (1980) reported “large variation in copulatory
durations (1–165 h), number of copulations per individual (1–9), and time in copula prior to oviposition
(1–176 h)”. Borges et al. (1987) added more detailed descriptions related to long-range mate location
(including pheromone extracts from males) and short-range courtship (including the indication that
visual and acoustic stimuli affect mate location). Pheromone extracts contain n-dodecane, n-tridecane,
sesquiterpene (hydrocarbon), sesquiterpene (mono-oxygenated), and n-nonadecane and play a key role
in long-range mate location (later discussed in Section 7. 4 .6). Males are polygamous and females are
polyandrous.