Use of Phenylacetonitrile Plus Acetic Acid to Monitor Pandemis Pyrusana

bioRxiv preprint doi: https://doi.org/10.1101/092452; this version posted January 4, 2017. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. doi: http://dx.doi.org/10.1101/092452 El-Sayed and Suckling: Use of phenylacetonitrile plus acetic acid to monitor Pandemis leafroller 2016

components. Further studies are warranted Use of phenylacetonitrile to develop phenylacetonitrile and possibly other aromatic plant volatiles as bisexual plus acetic acid to lures for the range of tortricid pests monitor Pandemis attacking horticultural crops.

pyrusana (Lepidoptera: KEY WORDS: codling moth, leafroller, host- plant volatile, phenylacetonitrile Tortricidae) in apple INTRODUCTION Ashraf M. El-Sayed1*, David M. Suckling1,2 Pandemis spp. leafrollers are an important group of tortricid pests attacking pome 1The New Zealand Institute for Plant & Food fruits (apple, Malus domestica Borkhausen, Research Limited, and pear, Pyrus communis L.), in North Gerald Street, 7608, America (Chapman 1973, Dombroskie and Lincoln, New Zealand Sperling 2012) and in Europe and Asia

(Dickler 1991). These species are often 2School of Biological Sciences, University of Auckland bivoltine and overwintering larvae in the fall- Tamaki Campus, Building 733, spring and summer generations feed on the Auckland, New Zealand skin of developed fruits adjacent to leaves creating cull fruits (Brunner 1996). *Author for correspondence: Insecticides are most often used to manage [email protected] these pests; although sex pheromone mating disruption has been developed and ABSTRACT A recent discovery has implemented on a relatively small acreage in demonstrated that herbivore induced plant North America (Judd and Gardiner 2008). volatile compounds from apple trees infested Sex pheromone-baited traps are used to with larvae were highly attractive to con- monitor adult populations to assess both specific adult male and female leafrollers. density and phenology, but pest managers However, this work (conducted in New feel they are insensitive to local population Zealand and Canada) tested only low doses densities within the orchards (Brunner of kairomone. Our US study here was 1984). Alternative lures, including acetic conducted to assess the attractiveness of acid, have been evaluated to monitor both higher doses of the six apple volatiles sexes of Pandemis pyrusana (Kearfott) putatively identified from apple trees (Knight, 2001); however, acetic acid alone infested by tortricid larvae to the leafroller, was considered to be a weak lure and was Pandemis pyrusana Kearfott. These volatiles not adopted by Washington State growers to included: β-caryophyllene, germacrene D, monitor P. pyrusana (Alway 2003). benzyl alcohol, phenylacetonitrile, (E)- nerolidol, and indole. No volatiles were Apple seedlings uniquely release several attractive to P. pyrusana when used alone. compounds, including acetic acid, acetic However, traps baited with anhydride, benzyl alcohol, phenylacetonitrile plus acetic acid caught phenylacetonitrile, indole, 2-phenylethanol, both sexes of P. pyrusana. Traps baited with and (E)-nerolidol only when infested by the other volatiles plus acetic acid caught larvae of light brown apple moth (LBAM), zero to only incidental numbers of moths (< Epiphyas postvittana (Walker), the 1.0). Interestingly, traps baited with obliquebanded leafroller (OBLR), C. phenylacetonitrile plus acetic acid caught rosaceana (Harris), and the eye-spotted bud significantly more P. pyrusana than traps moth (ESBM), Spilonota ocellana (Denis & baited with a commercial sex pheromone Schiffermüller) (Suckling et al. 2012; El- lure. The evaporation rate of the acetic acid Sayed et al. 2016). Recently El-Sayed et al. co-lure was an important factor affecting (2016) found that a binary blend of the two catches of P. pyrusana with herbivore-induced plant volatile compounds phenylacetonitrile, and studies are needed (HIPVCs), phenylacetonitrile + acetic acid to optimize the emission rates of both lure and 2-phenylethanol + acetic acid, attracted

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a significant number of conspecific male and Sept. 2013. In addition, the proprietary female adult LBAM in New Zealand. Further lures: Pherocon CM-DA lure loaded with investigation with other leafrollers pear ester, the Pherocon CM-DA combo lure (Tortricidae) in Canada, including the ESBM loaded with codling moth sex pheromone and OBLR, revealed similar systems. The and pear ester, and the Pherocon PLR lure study reported by El-Sayed et al. (2016) (#3147) loaded with the P. pyrusana sex targeted mainly ESBM and OBLR using a pheromone were obtained from Trécé Inc. lower doses of the new kairomone. In this study we have investigated the response of Field experiment protocols. Studies evaluated P. pyrusana to the compounds reported by single, binary, and ternary blends of El-Sayed et al. (2016) using higher doses of selected host-plant volatiles and acetic acid the HIPVCs in Washington State during co-lures using a standardized protocol in 2012–2014. Also, studies were conducted to 2012 and 2013. Studies were conducted in evaluate possible interactions with any of two apple orchards, the USDA research farm the attractive volatiles when combined with situated east of Moxee, WA (46o30’N, pear ester and acetic acid in binary and 120o10’W), and in a commercial orchard ternary blends for moth catches of both C. located southwest of Naches, WA (46o43’N, pomonella and P. pyrusana in the same trap. 120o42’W). Orange delta traps with sticky inserts (Pherocon VI, Trécé Inc.) were used MATERIALS AND METHODS in all studies. Five replicates of each lure Chemicals and Lures. Chemical purity of the treatment were randomized and spaced 20– volatile apple chemicals used in our trials 30 m apart. Traps were placed at a 2 m were as follows: benzyl alcohol (99%), (E)- height in the canopy. All lures were placed nerolidol (85%), phenylacetonitrile (99%), on the liner. Acetic acid vials with 3.2 mm indole (99%), β-caryophyllene (97%), and holes were used in all studies unless germacrene D (96%) (Sigma Aldrich, St. specified otherwise. Traps baited with a Louis, MO). These chemicals were loaded blank sachet lure were used as a negative (100 mg) into plastic sachet. Sachet lures control in each study. Studies were repeated consisted of a heat-sealed, semi-permeable a variable number of times and typically polyethylene bag (45 mm x 50 mm, 150 µm each test ran for 5–7 d. When studies were wall thickness), with a piece of cellulose repeated on different dates all traps were acetate filter (15 mm × 45 mm, Moss collected, new lures were transferred to new Packaging Co. Ltd., Wellington, New liners, and traps were re-randomized in the Zealand) inserted as the carrier substrate. field. Moths were sexed in all studies. Two acetic acid (glacial acetic acid (99.7%), Sigma Aldrich) co-lures were made by Comparison of induced volatiles. Plant drilling either 1.0 or 3.2 mm holes in the cap volatiles, reportedly induced by tortricid of 8 ml Nalgene vials (Nalg-Nunc larval feeding on apple and attractive to International, Rochester, NY) and loading adults (El-Sayed et al., 2016), were each vial with two small cotton balls and 5 evaluated in two consecutive studies in the ml of glacial acetic acid. A third acetic acid Moxee orchard during 2013. The first study lure, a proprietary round (3.4 cm diameter) compared moth catches from 12–19 Aug. in plastic membrane cup (Pherocon AA) was traps baited with phenylacetonitrile, benzyl provided by Trécé Inc. (Adair, OK). The mean alcohol, indole, (E)-nerolidol, β- weekly weight loss (evaporation rate) of caryophyllene, or germacrene D; and the acetic acid from the three lures was combination of phenylacetonitrile with an recorded from 30 Aug. to 26 Sept. 2013. acetic acid co-lure. The second study Individual lures (N = 10) were placed in red compared these same six volatiles all in Pherocon VI delta traps (Trécé Inc.) without combination with acetic acid co-lures sticky liners that were hung in the canopy of against acetic acid alone from 19–28 Aug. five linden trees, Tilia cordata Miller, at the Yakima Agricultural Research Laboratory, Combination lures with phenylacetonitrile. Wapato, WA. Similarly, the weight loss of Studies conducted in both 2012 and 2013 sachet lures loaded with phenylacetonitrile evaluated phenylacetonitrile alone, and in (N = 5) was recorded from 28 Aug. to 19 combination with either pear ester or acetic

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acid, pear ester with acetic acid, and plant volatiles during Test 1 in the Moxee phenylacetonitrile plus pear ester and acetic orchard (Table 1). In comparison, small acid in order to determine whether numbers of moths were caught when acetic interactions would affect catches of either or acid was added as a co-lure to traps baited both target species. Traps in 2012 were with phenylacetonitrile (Table 1). During thehe initially placed in the Moxee orchard on 1 second test comparing these six volatiles in Aug. and traps were checked and re- combination with acetic acid, no moths werere randomized on 8 Aug. This study was caught with β-caryophyllene, germacrene D, terminated on 13 Aug. and traps were or acetic acid alone. Incidental moth catcheses moved to the Naches orchard. Traps were occurred in blank traps and in traps baited checked and re-randomized in this orchard with (E)-nerolidol lures. Means > 1 moth perer on 22 and 30 Aug., and the study was trap were caught with acetic acid plus eitherer terminated on 12 Sept. This same study was benzyl alcohol, indole or phenylacetonitrile. repeated in 2013 from 20–27 June at both The bisexual total and female moth only the Moxee and Naches orchards and from 5– catches were significantly greater with acetictic 12 and 17–27 Aug. in the Moxee orchard. A acid plus phenylacetonitrile than the other third study was conducted from 7–21 July two volatiles plus acetic acid co-lure 2014 in the Moxee orchard to evaluate the combinations (Table 1). use of phenylacetonitrile with the sex pheromone / pear ester combinational lure Table 1. Comparison of catches of Pandemis and the acetic acid cup lure. A final study leafroller in traps baited with different host- plantnt was conducted in the Naches orchard from volatiles alone (Test 1) or in combination with 30 Aug. to 10 Sept. 2014, to compare the acetic acid (Test 2), N = 5, Moxee, WA, 2013. magnitude of the total bisexual moth catches of P. pyrusana in traps with phenylacetonitrile plus acetic acid with male catches in traps baited with P. pyrusana sex pheromone.

The acetic acid evaporation rate was evaluated over three time periods in the Moxee orchard during 2013. Traps baited with phenylacetonitrile sachet lures plus acetic acid vials with either 1.0 or 3.2 mm holes or the Pherocon AA cup lure were compared. New lures were used in each of three separate studies which were conducted from 28 Aug. to 4 Sept., 4–11 Sept., and 12–19 Sept. 2013.

Statistical analyses. Count data were subjected to a square root transformation prior to analysis of variance (ANOVA) to normalize the variances. A randomized, complete block design was used in most studies with date as the blocking variable. Following a significant F-test in the ANOVA, means were separated with Tukey’s HSD test with an alpha value of 0.05. Treatments Column means for test 2 followed by a different with zero catches or only incidental catch letter were significantly different in a one-way were not included in these analyses. ANOVA, Tukey’s HSD test, P < 0.05. aEach plant volatile was loaded on a felt pad in plastic sachets in aliquots of 100 µl. Acetic acid RESULTS (5 ml) was loaded on cotton balls in plastic vials Comparison of induced volatiles. No P. with a 3.1 mm hole. pyrusana were caught with any of the six

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significant differences among treatments Combination lures with phenylacetonitrile. were found for female moth catch. Also, totaltal Consistent data were collected in both 2012 moth catch in traps baited with pear ester and 2013 when comparing catches of C. plus acetic acid in 2012 was not pomonella with phenylacetonitrile alone and significantly different from the four with binary and ternary blends including treatments that included phenylacetonitrile. pear ester and/or acetic acid (Tables 2 and 3). Pear ester in combination with acetic The average evaporation rate of acetic acid acid caught significantly more total and from the co-lures used with female C. pomonella than other lures. phenylacetonitrile was a significant factor Adding phenylacetonitrile to pear ester and affecting moth catches of P. pyrusana (Tablele acetic acid significantly reduced both total 4). Evaporation rates ranged 18-fold across and female moth catches of C. pomonella. the three dispensers tested. Moth catches Catches of C. pomonella with either were significantly lower in traps containing phenylacetonitrile alone and in binary acetic acid lures with the lowest evaporationon blends with either acetic acid or pear ester rate (plastic cup lure), and did not differ were low and did not differ significantly. In between traps baited with plastic vials with addition, traps with phenylacetonitrile alone the two different hole sizes. Sachet lures in the 2013 test caught numbers of C. loaded with phenylacetonitrile evaporated an pomonella similar to numbers captured by average (SE) of 6.3 (0.2) mg d-1. either acetic acid or pear ester alone. Adding phenylacetonitrile to traps baited with the Table 2. Comparison of catches of codling moth and Pandemis leafroller in orange delta traps sex pheromone-pear ester combination lure unbaited or baited with combinations of (Pherocon CM-DA) plus acetic acid did not phenylacetonitrile, pear ester, and acetic acid, N significantly reduce male, female, or total =10 for codling moth and N= 15 for Pandemis moth catches in 2014 (Fig. 1). leafroller, Naches, WA 2012.

Fig. 1. Mean (SE) number of male, female, and total Cydia pomonella caught in traps with a sex pheromone + pear ester combo lure and an acetic acid co-lure versus these same lures with the addition of a phenylacetonitrile sachet lure, 7–21 Means followed by a different letter were July 2014, Moxee WA. ‘N.S.’ denotes a significantly different in a randomized complete nonsignificant difference in moth catches block ANOVA, Tukey’s HSD test, P < 0.05. between the two types of lures, P > 0.05. aPhenylacetonitrile was loaded on a felt pad in plastic sachets at 100 µl. Pherocon CM DA lures Counts of P. pyrusana were more variable in contained 3.0 mg pear ester. Acetic acid (5 ml) traps than captures of codling moth between was loaded on cotton balls in plastic vials with a both years of the study (Tables 2 and 3). 3.2 mm hole. During 2013, traps baited with bExperiments were repeated on two dates in the phenylacetonitrile plus acetic acid or in Moxee orchard: 1–8 and 8–13 Aug. combination with pear ester caught cData from blank traps for both species and withh significantly more total and female moths PA lures for C. pomonella were not included in the analysis. than all other treatments and did not differ among themselves. However, moth catches in 2012 were lower than in 2013 and no

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Moth catches of P. pyrusana in traps placed block ANOVA, Tukey’s HSD test, P < 0.05. in the Naches orchard were much higher aPhenylacetonitrile was loaded on a felt pad in during 2014 than in the two previous years plastic sachets at 100 µl. Pherocon CM DA lures (Fig. 2). Total moth catch was significantly contained 3.0 mg pear ester. Acetic acid (5 ml) was loaded on cotton balls in plastic vials with a different and nearly 6-fold higher in traps 3.2 mm hole. baited with phenylacetonitrile than with the bExperiments were repeated on four orchard- sex pheromone of P. pyrusana (F 1, 8 = 54.64, dates: 20–27 June in both the Moxee and Nacheses P < 0.001). Mean catch of both male (F 1, 8 = orchards, and from 5–12 and 17–27 Aug. in the 9.30, P < 0.05) and female (F 1, 8 = 20.01, P < Moxee orchard. 0.01) moths alone were both significantly cData from blank traps were not included in the higher with this binary lure than the catch analyses. of males in the sex pheromone-baited traps DISCUSSION In the studies reported here, phenylacetonitrile and other plant volatiles known to be induced by insect feeding, including benzyl alcohol, indole,le, and acetic acid provided no intrinsic attraction of P. pyrusana when tested alone. However, when any of the three compounds was combined with acetic acid all, and especially phenylacetonitrile, exhibited strong attractiveness to adult male and female

P. pyrusana. Phenylacetonitrile and Fig. 2. Mean (SE) number of male, female, and acetic acid have been reported as total Pandemis pyrusana caught in traps baited herbivore induced plant volatiles in with either the sex pheromone lure for P. apple as a result of LBAM larval feeding,g, pyrusana (males only) or with phenylacetonitrile plus an acetic acid co-lure (males, females, and while phenylacetonitrile was also total moths). ‘*’ denotes a significant mean identified as herbivore induced plant difference with male catch in the sex pheromone- volatile in apple as results of OBLT and baited trap, P < 0.05. ESBM larval feeding (El-Sayed et al., Table 3. Comparison of catches of codling moth 2016). It is probable that the effects are and Pandemis leafroller in orange delta traps caused by fatty acid-amino acid unbaited or baited with combinations of conjugates in caterpillar saliva phenylacetonitrile, pear ester, and acetic acid, N (Yoshinaga et al. 2010), although this =20, Moxee, WA 2013. has not been demonstrated directly for Tortricidae as yet. In our previous work,k, conducted in apple orchards in Canada,a, combinations of phenylacetonitrile and acetic acid or 2-phenylethanol and acetic acid were attractive to adult malele and female OBLR and ESBM. The results obtained in this study combinedd with earlier results with other tortricids suggest the positive response of adult tortricids to HIPV compounds is a widespread phenomena among these species. Phenylacetonitrile has previously been studied with several Means followed by a different letter were tortricids and host-plant material in significantly different in a randomized complete

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laboratory studies. For example, volatiles, serves as an adult aggregationn phenylacetonitrile was one of 22 kairomone (Loughrin et al. 1995). compounds identified from the Phenylacetonitrile was shown to be headspace (< 0.5%) of excised peach released from cabbage, Brassica spp., shoots, Prunus persica L. (Natale et al. and nasturtium, Tropaeolum majus L., 2003), but was not found to be following larval feeding of P. brassicae attractive to mated female Grapholita and P. rapae L., but not from molesta (Busck), when used in a blend undamaged plants (Geervliet et al. with three green leaf volatiles plus 1997). In apple, a significant difference benzaldehyde (Piñero and Dorn 2007). in the release of phenylacetonitrile was Apple leaves also released found among four cultivars, including phenylacetonitrile within a blend of two transgenic scab resistant cultivars volatiles in response to larval feeding by (Vogler et al. 2010). the tortricids E. postvittana (Suckling et al. 2012) and P. heparana (Giacomuzzi Table 4. Comparison of catches of Pandemis leafroller in orange delta traps baited with et al. 2013). Yet, neither study phenylacetonitrile plus one of three different measured whether it was attractive to acetic acid co-lures, N = 15, Moxee WA, 2013. these herbivorous insects.

Phenylacetonitrile is a relatively well known semiochemical involved in a range of insect-insect and insect-plant interactions. These include serving as a male-produced anti-aphrodisiac in the butterfly Pieris brassicae L.; facilitating a phoretic dispersal and arrestment by female egg parasitoid Trichogramma Means followed by a different letter were significantly different in a randomized complete brassicae Bezdenko (Fatouros et al. block ANOVA, Tukey’s HSD test, P < 0.05. 2005, Huigens et al. 2009); and acting aAcetic acid lures included the proprietary as a male-specific repellant in the Pherocon AA (Trécé Inc., Adair, OK) plastic cup locust, Schistocerca gregaria (Forskal) in and polypropylene vials filled with 5 ml of acetic order to manage sperm competition acid and with either 1.0 or 3.2 mm holes. Phenylacetonitrile sachet lures released an within insect aggregations (Seidelmann average (SE) of 6.3 (0.2) mg d-1. and Ferenz 2002). Phenylacetonitrile is bExperiments were repeated on three dates: 28 also released by male and female flowers Aug.–4 Sept., 4–11 Sept. and 12–19 Sept. 2013 in of boxelder trees, Acer negundo L., and the Moxee orchard. it alone attracts nymphs, and both Previous studies with plant-feeding sexes of the adult box elder bug, Boisea Lepidoptera (primarily noctuids and rubrolineata (Barber) (Schwarz et al. pyralids) have correlated the presence of 2009). Phenylacetonitrile was isolated larval feeding on a host plant with the from oilseed rape, Brassica napus L., repulsion of the con-specific adults and shown to attract cabbage seed (Landolt 1993, De Moraes et al. 2001, weevil, Ceutorhynchus assimilis Payk Signoretti et al. 2012, Reisenman et al. (Smart and Blight 1997). Similarly, 2013, Zakir et al. 2013, Hatano et al. phenylacetonitrile is induced by feeding 2015). No previous studies on tortricid of the Japanese beetle, Popillia japonica moths have reported whether adults cueue Newman, and the fall webworm, to host-plant volatiles induced by larval Hyphantria cunea Drury, on several feeding. When presented alone the plant species, including crabapple, induced plant volatiles examined in thisis Malus sp., and within a blend of induced study exhibited no attraction to adult P.

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pyrusana based on the absence of grapes, Vitis vinifera L., (Tasin et al. moths in traps. However, we did not 2005, 2011). In this system, neither study whether these induced volatiles acetic acid nor the induced volatile 2- were behaviorally repellent or interfered phenylethanol was collected from with volatile-mediated host selection undamaged flowers and fruit (Tasin et and/or sex pheromone communication al. 2005). However, both compounds (Hatano et al. 2015). were abundant in volatiles from fruit infested with yeasts or acetic bacteria, Our findings suggest that acetic acid is and both female oviposition and net an important synergist of herbivore- reproductive rate were significantly induced plant volatiles for adult P. increased as a result of microbial pyrusana. Interestingly, acetic acid has infestations of fruit (Tasin et al. 2011). rarely been reported in the analysis of In contrast, fruit infected by Botrytis volatile collections from damaged apple cinerea (Persoon), did not release acetic foliage; trace levels were found in acid and was repulsive to females and samples of cut flowering apple branches reduced the overall fitness of the insect. (Bengtsson et al. 2001), from apple Inoculation of fruit with acetic bacteria leaves infested with phytophagous mites produced > 100-fold higher levels of (Llusia and Peñuelas 2001), and from acetic acid than with the yeasts, and drought-stressed trees (Ebel et al. 1995). oviposition was reduced compared with Interestingly, an earlier paper found clean fruit, suggesting an overdose of phenylacetonitrile was released by acetic acid can occur. In our studies, spider mite damage on apples the higher emission rates of acetic acid (Takabayashi et al. 1994). Acetic acid is tested were more attractive, but neither a primary metabolite of plant the emission rates of phenylacetonitrile metabolism under stress conditions and nor acetic acid have been optimized for is regulated by the production and attraction of P. pyrusana. catabolism of ethanol and acetaldehyde (Oikawa and Lerdau 2013). However, Our studies can likely impact the pest acetic acid could also be produced by management of P. pyrusana. the growth of yeast and bacteria Surprisingly, traps baited with prevalent in the phyllosphere of apple phenylacetonitrile and acetic acid leaves, or on surfaces of senescent caught more moths than sex pheromone flowers which are relatively rich in traps in an orchard not treated with sugars and other carbohydrates (Atlas leafroller sex pheromones. These data and Bartha 1981, Kinkel 1997). A may suggest that the commercial lures potential role for microorganisms in the for P. pyrusana are not optimized or that herbivore induction of plant volatiles other species in the Pandemis limitata has been suggested previously (Dicke (Robinson) group with different sex and Hilker 2003, Hilker and Meiners pheromone blends are more dominant 2006); yet, few studies have tried to in the two orchards studied measure this interaction. One exception (Dombroskie and Sperling 2012). The was the purported role of regurgitated respective sex pheromones of P. limitata endosymbionts in the induction of plant and P. pyrusana have been identified as defenses (Spiteller et al. 2000). 91:9 and 94:6 blends of (Z)-11- tetradecenyl acetate and (Z)-9- The interplay of microbial and plant tetradecenyl acetate (Roelofs et al. 1976, volatiles with an adult tortricid pest has 1977). At least one commercial lure has perhaps best been studied with Lobesia been reported to be relatively ineffective botrana (Denis and Schiffermüller) on for P. pyrusana due to contamination

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with < 1.0% of (Z)-9-dodecenyl acetate infested plants (Bruce and Pickett (Brunner and Fisher 1998). 2011). For example, green leaf volatiles have been found to enhance catches We found that adding pear ester to traps with sex pheromones in field trials with baited with phenylacetonitrile and acetic some tortricid pests (Light et al. 1993, acid did not reduce the catch of P. Varela et al. 2011, Yu et al. 2015). The pyrusana. However, adding release rates of both (Z)-3-hexenyl phenylacetonitrile to traps baited with acetate and (Z)-3-hexenyl benzoate were pear ester and acetic acid significantly increased with herbivory (Suckling et al. reduced catches of C. pomonella. Thus 2012), and in a previous study ternary blends in a single trap would be combining (Z)-3-hexenyl acetate with useful in monitoring P. pyrusana, but acetic acid nearly doubled the catch of may compromise catches of C. P. pyrusana (Knight et al. 2014). pomonella. However, a significant drop Polyphagous tortricid pests such as P. in catch of C. pomonella did not occur pyrusana attack a number of when phenylacetonitrile and acetic acid horticultural crops other than pome were added to the combination sex fruits. Future studies should more pheromone plus pear ester lure. The broadly characterize the induced plant potential benefit of improved monitoring volatiles in these crops to identify other of P. pyrusana, especially of female possible attractants, including green leaf moths, with phenylacetonitrile would volatiles, aromatics, alcohols, and have to outweigh the information lost terpenes, and test these in combination from a drop in catches of female C. with acetic acid as attractive lures. It is pomonella in these combination traps likely that systematic screening can now (summarized in Knight et al. 2014). improve these lures for pest Hypothetically, this could occur in management of several target species. certified-organic orchards if the pest pressure from C. pomonella is low, REFERENCES efficacious tools to manage leafrollers Alway, T. 2003. Exploring alternatives to are limited and, especially, when sex organophosphate insecticides with apple pheromone-based mating disruption for and pear: the Areawide II Project in leafrollers is used and the standard sex Washington State. Compact Fruit Tree 36: 91–93. pheromone-baited traps are ineffective.

The ability to monitor multiple species Atlas, R. M. and R. Bartha. 1981. Microbial could fuel the adoption of labor-saving ecology: fundamentals and applications. remote electronic traps (Guarnieri et al. CAB, London, United Kingdom. 2011, Kim et al. 2011). Bengtsson, M., A.-C. Backman, I. Liblikas, Our positive results with enhancing the M. I. Ramirez, A.-K. Borg-Karlson, L. bisexual moth catches of P. pyrusana Ansebo, P. Anderson, J. Lofqvist, and P. suggest that studies should continue to Witzgall. 2001. Plant odor analysis of apple: identify and test other plant volatiles antennal response of codling moth females induced by insect feeding on pome fruits to apple volatiles during phenological (Boevé et al. 1996, Suckling et al. 2012, development. J. Agric. Food Chem. 49: Giacomuzzi et al. 2013, El-Sayed et al. 3736−3741.

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