Semiochemistry of Pentatomoidea 699
15.2.16 Sehirus cinctus (Palisot de Beauvois) [Cydnidae: Sehirinae]
The white-margined burrowing bug (Sehirus cinctus) exhibits brooding behavior in which the female
provisions the nymphs with food in response to “solicitation pheromones.” Kölliker et al. (2006) found
that mother bugs already caring for offspring, and then exposed to volatiles from artificially-reared
but poorly-fed nymphs, fed these nymphs significantly more compared to no exposure, or to exposure
to volatiles from well-fed nymphs. At least eight compounds were identified in these volatiles, includ-
ing α-pinene and camphene; however, these two chemicals did not elicit the feeding response evoked
by the full blend. Interestingly, in the closely-related Parastrachia japonensis Scott (Heteroptera:
Parastrachiidae), mothers signal their nymphal offspring with a distinct provisioning song when arriving
with drupe fruits of the plant host (Nomakuchi et al. 2012).
- 2.17 Tessaratoma papillosa (Drury) [Tessaratomidae: Tessaratominae]
The litchi stink bug, Tessaratoma papillosa, is a serious pest of litchi, longan, and rambutan fruit in
tropical Asia. Zhao et al. (2012) and Wang et al. (2012) described metathoracic glands and their con-
tents from males and females, including differences in presumably allomonal chemical contents, along
with electroantennogram and behavioral responses. Unfortunately, as in the case of several species of
Scutelleridae (Millar 2005), behavioral evidence is not clear for what Wang et al. (2012) call “a complex
pheromone system in T. papillosa.” The authors state that males are attracted to secretions from females,
but the pheromone has not yet been characterized properly.
15.2.18 Thyanta custator (F.), Thyanta pallidovirens (Stål), and Thyanta
perditor (F.) [Pentatomidae: Pentatominae: Antestiini]
Moraes et al. (2005a) identified a male-produced sex pheromone of the neotropical red-shouldered
stink bug, Thyanta perditor, one of a complex of pentatomids attacking soybeans in Brazil, as methyl
(2E,4Z,6Z)-2,4,6-decatrienoate ( 73 , Figure 15.14). The structure was confirmed by comparisons with
retention times and spectra of an authentic standard (Millar 1997). It was attractive to females but not
males in Y-tube bioassays. Thyanta perditor is the third Thyanta species, in addition to T. pallidovirens
and T. custator accerra (McBrien et al. 2002), shown to use methyl (2E,4Z,6Z)-2,4,6-decatrienoate as
a pheromone component. However, this compound appears to be the only pheromone component in the
case of T. perditor, attracting conspecific females as a single component, whereas the pheromones of
T. pallidovirens and T. custator accerra are more complex, and at least one of the three sesquiterpenes,
(+) -α-curcumene, (-)-zingiberene, or (-)-β-sesquiphellandrene, produced by the males, is required in
order for the latter two species to be attracted (McBrien et al. 2002). The pheromones of the latter two
species were reviewed in Millar (2005), including syntheses of the various pheromone components.
All stereoisomers of methyl 2,4,6-decatrienoates have strong UV absorptions at ~ 300 nm (Millar
1997, Khrimian 2005, Moraes et al. 2005a) and, hence, are unstable in sunlight (Khrimian 2005,
Khrimian et al. 2008). Thus, a solution of Plautia stali pheromone 66 (Figure 15.13) left unprotected
under ambient conditions isomerized to a mixture of stereoisomers in which isomers 69 and 71 were the
main byproducts (Khrimian et al. 2008). A similar trend was noticed when rubber septa impregnated
with 66 were exposed to sunlight. The pheromone of Thyanta pallidovirens, ester 73 , both in a hexane
solution and impregnated into rubber septa, isomerized in sunlight producing a mixture of geometric
isomers, among which esters 66 and 71 were most abundant. Thus, at first glance the instability of
these methyl 2,4,6-decatrienoate pheromones might seem problematic for their practical application in
monitoring various target pests. However, Laumann et al. (2011) showed that traps baited with methyl
(2E,4Z,6Z)-2,4,6-decatrienoate ( 73 ), protected from direct sunlight or not, attracted T. perditor females
in a field trial in Brazil. Interestingly, even methyl (2E,4E,6Z)-2,4,6-decatrienoate ( 66 ) was somewhat
attractive to T. perditor (Laumann et al. 2011), but whether or not this isomer is intrinsically attractive
or whether it isomerized to the (2E,4Z,6Z)-isomer under field conditions, remains unanswered and, for
practical purposes, does not matter. Methyl (2E,4Z,6Z)-2,4,6-decatrienoate also cross-attracted other
species of stink bugs to some extent, including Euschistus heros, Edessa meditabunda, Piezodorus