712 Invasive Stink Bugs and Related Species (Pentatomoidea)
~0.2 μg/bug/day of bisabolene epoxides 1 and 2, respectively (Blassioli-Moraes et al. 2012). In contrast,
the quantities of defensive compounds produced by both sexes of Pentatomoidea typically are much
higher than those of the male-produced pheromones (Aldrich 1988; see, for example, quantification by
de Oliveira et al. [2013]).
Dose-response studies testing male-produced aggregation pheromones in field trials typically have
shown increasing attraction and trap captures up to very high doses and, presumably, release rates.
Leskey et al. (2015b) quantified captures of Halyomorpha halys in pheromone-baited traps as well as
attraction to the vicinity of lures for four orders of magnitude of lure loading, from 0.02 to 200 mg of 37
and 0.008 to 80 mg of 38 , with a clear dose response, with or without the addition of 66 , the Plautia stali
pheromone, the latter in a commercial lure reported to contain 66 mg. Weber et al. (2014b), using rubber
septum lures loaded with 0.02 to 20 mg each of 37 and 44 , showed increased attraction of Murgantia his-
trionica adults with increasing doses of the blend of components, with or without host plants. However,
the presence of plants strongly enhanced overall captures. Tests of the interaction between component
ratios and dose, as well as quantification of release rates, is ongoing for H. halys (T. Leskey, pers. comm.)
and M. histrionica (D. W., unpublished data). Plastic pellets formulated by Fuji Flavor Co. (Japan) with
different doses of methyl-2,6,10-trimethyltridecanoate (0.004, 0.01 and 1 mg) were evaluated in labora-
tory bioassays with E. heros females, and all doses tested attracted significantly more females than the
clean air controls (M. Borges, pers. comm.).
In field bioassays, most studies have tested lures loaded with 10 or more bug equivalents per lure, but
there have been few attempts to quantify release rates and the ratios actually emitted. However, Millar
et al. (2010) showed that differing release rates of Chlorochroa sayi pheromone components from rubber
septa resulted in changes in emitted blend ratios over time. Borges et al. (2011), using a lure formulated
by Fuji Flavor (Japan) containing 1 mg of methyl-2,6,10-trimethyltridecanoate, showed that from day 12^
until day 50, the release rate of the pheromone was ≈10 ng/day. This amount is approximately 1,000 times
less than that produced by male E. heros per day (Zhang et al. 2003, Moraes et al. 2008c), but, neverthe-
less, the pheromone traps attracted females until day 49 (Borges et al. 2011). A variety of slow-release
technologies may be required to optimize release rates and field longevities of stink bug pheromones of
different chemistries.
15.5.2 Current Role of Stink Bug Semiochemicals in Pest Management
Use of stink bug pheromones in pest management currently is limited to monitoring the phenology and
abundance of populations of a few major pest species to determine the need for suppressive treatments.
Examples include Euschistus conspersus in California tomatoes (Cullen and Zalom 2007), E. heros in
Brazilian soybeans (Borges et al. 2011), and Plautia stali and other fruit-piercing bugs in tree fruit in
Japan (Adachi et al. 2007, Yamanaka et al. 2011). Furthermore, Leskey et al. (2015a) employed hundreds
of traps to monitor the abundance and phenology of Halyomorpha halys across ten states in the United
States as part of a continuing effort to define infestations and damage to crops and to monitor for this
invasive pest.
Use of stink bug pheromones in mass trapping, trap-cropping, or other suppression tactics has not
been implemented although there is continuing interest in development of such methods. Several experi-
ments have tested “trap plants” treated with aggregation pheromones to attract pest species, and, in some
cases, the plants also were treated with systemic insecticides to kill bugs that were attracted (Katase et al.
2007 and Yamanaka et al. 2011 for P. stali; D. W., unpublished data, for Murgantia histrionica). The
“trap tree” concept currently is being tested, using the combined attractants for Halyomorpha halys and
other stink bug pests of tree fruit in North America (T. Leskey, pers. comm.). None of these methods has
yet advanced to commercial implementation. Successful implementation of management of stink bugs
based on semiochemicals will require careful evaluation of each species for the likelihood of success,
taking into account the pheromone chemistry, the life history and host specificity of the target, ecologi-
cal (abiotic and biotic) characteristics of the agroecosystem (Millar 2007), and the costs of synthesis and
deployment of pheromone devices.
Despite the frequently noted effects of pentatomoid semiochemicals on natural enemies, particularly
tachinid flies and hymenopteran egg parasitoids, no methods based on host pheromones or allomones