698 Invasive Stink Bugs and Related Species (Pentatomoidea)
in situ olefination of the intermediate aldehyde, in 51% overall yield. The original synthesis of ester 73
had used a one-pot double-carbocupration of acetylene with subsequent addition to methylpropiolate
(Millar 1997).
With the Plautia stali pheromone commercially available from Shin-Etsu Chemical Co., Japanese
researchers optimized pheromone-based trapping protocols to monitor this species in Asian pears and
other tree fruit (Kakogawa et al. 2007). The traps are pyramidal, and first were yellow before being
changed to clear in color, and are topped with a chamber with the pheromone lure and dichlorvos as a
killing agent (Adachi et al. 2007, Katase et al. 2007). The lure also attracted H. halys (vide supra) and
Glaucias subpunctatus (Walker) (Pentatomidae), both of which are significant fruit pests. The former
now is known to emit a completely different male-produced pheromone as described above, whereas no
pheromones have been identified yet for the latter species (Adachi et al. 2007, Katase et al. 2007).
The widespread planting of conifers, especially sugi [Cryptomeria japonica D. Don (Taxodiaceae)]
and hinoki cypress [Chamaecyparis obtusa (Siebold & Zucc.) (Cuppressaceae)], has resulted in an abun-
dant food source for all three bug species (i.e., G. subpunctatus, H. halys, P. stali), which feed on the
cones and produce mass dispersals from this food source to fruit orchards up to 4 km distant (Kiritani
2007, Taki et al. 2014). To address these outbreaks, two pheromone-based suppression methods were
tested: autodissemination of the entomopathogen Beauveria bassiana E-9102 (Tsutsumi et al. 2003), and
use of trap plants poisoned with a systemic insecticide (Katase et al. 2007, Yamanaka et al. 2011). The
autodissemination experiment increased mortality in the bugs from near zero in controls to 28-35% in
the treated area to 70-75% in adults collected at the inoculation station (Tsutsumi et al. 2003). However,
this method apparently has not been applied on a commercial scale. In a pilot test of systemic insecticides
combined with pheromones, Katase et al. (2007) injected a potted sugi tree with the organophosphate
insecticide acephate and baited it with P. stali pheromone, attracting and killing ~5000 bugs in 3 days.
In a more ambitious trial, Yamanaka et al. (2011) used large potted (>1m tall) Solanum torvum Swartz
(wild eggplants) baited with 34 mg of P. stali pheromone and poisoned with 1 g of imidacloprid per pot
(~130-200 times the United States labeled field rate for eggplant). Poisoned eggplants were stationed at
50 m intervals around each of three persimmon orchards, with three control orchards. The border trap
crop failed to reduce overall damage in the orchard. Damage was highest closest to the trap plants and,
in related experiments, losses were elevated within a so-called spillover area of up to 150 m around the
treated plants, as measured by fruit dropped within 7 days. The authors concluded that trap plants should
be at least 100 m away from the crop that needed protection, and that attract-and-kill or push-pull strate-
gies would have to adhere to this spatial limitation for any chance of success.
74 75 73 (51%)abc bOH79 (59%)76 (4%)80 (3%)77 78OH
CO 2 CH 3CO 2 CH 3CO 2 CH 3CO 2 CH 3OHOH++FIGURE 15.14 Syntheses of four methyl (4Z)-2,4,6-decatrienoates including ester 73 , a pheromone component of
Thyanta spp. a) 1. DHP/PPTS, 2. dicyclohexylborane/AcOH/MeOH, 3. PPTS; b) 1. MnO 2 , CH 2 Cl 2 , 2. Ph 3 P=CHCO 2 Me;
(c) Zn(Cu/Ag), MeOH–H 2 O.