Monitoring oriental fruit moth (Lepidoptera: Tortricidae) with the Ajar bait trap in orchards under mating disruption

Studies in Oregon, California, Pennsylvania and Italy evaluated the relative performance of the Ajar trap compared with several other traps for the capture of Grapholita molesta (Busck), in pome and stone fruit orchards treated with sex pheromone dispensers for mating disruption. The Ajar is a delta‐shaped trap with a screened jar filled with an aqueous terpinyl acetate plus brown sugar bait solution (TAS) that opens inside the trap and is surrounded by a sticky liner. The TAS‐baited Ajar trap was evaluated with and without the addition of a sex pheromone lure and compared with a delta trap baited with a sex pheromone lure and a bucket trap filled with the TAS bait. Although the Ajar trap had a 90% lower evaporation of the TAS bait than the bucket trap, both of them caught similar numbers in the majority of the field tests of both sexes of G. molesta. The addition of the sex pheromone lure did not increase moth catches by the TAS‐baited Ajar trap. The TAS‐baited Ajar trap caught significantly greater numbers of moths than the sex pheromone‐baited delta trap in 18 of the 20 orchards. Few hymenopterans were caught in orange TAS‐baited Ajar traps, but the catch of flies and other moths relative to the target pest remained high. Flight tunnel and field tests evaluated the effect of several screen designs on the catches of G. molesta and non‐target species. All exclusion devices significantly reduced the catch of larger moths. However, designs that did not reduce the catch of male G. molesta did not reduce the catch of muscid flies. Exclusion devices with openings <7.0 mm significantly reduced the catch of female G. molesta. The addition of (E)‐β‐farnesene, (E)‐β‐ocimene or butyl hexanoate septa lures to TAS‐baited Ajar traps significantly increased total moth catch. The addition of (E)‐β‐ocimene also significantly increased female moth catch.     

Improved monitoring of oriental fruit moth (Lepidoptera: Tortricidae) with terpinyl acetate plus acetic acid membrane lures

Male and female moth catches of Grapholita molesta (Busck) in traps were evaluated in stone and pome fruit orchards untreated or treated with sex pheromones for mating disruption in Uruguay, Argentina, Chile, USA, and Italy from 2015 to 2017. Trials evaluated various blends loaded into either membrane cup lures or septa. Membrane lures were loaded with terpinyl acetate (TA), acetic acid (AA) and (Z)‐3‐hexenyl acetate alone or in combinations. Two septa lures were loaded with either the three‐component sex pheromone blend for G. molesta alone or in combination with codlemone (2‐PH), the sex pheromone of Cydia pomonella (L). A third septum lure included the combination sex pheromone blend plus pear ester, (E,Z)‐2,4‐ethyl decadienoate (2‐PH/PE), and a fourth septum was loaded with only β‐ocimene. Results were consistent across geographical areas showing that the addition of β‐ocimene or (Z)‐3‐hexenyl acetate did not increase moth catches. The addition of pear ester to the sex pheromone lure marginally increased moth catches. The use of TA and AA together significantly increased moth catches compared with the use of only one of the two components. Traps with the TA/AA lure outperformed the Ajar trap baited with a liquid TA plus sugar bait. The emission rate of AA was not a significant factor affecting the performance of the TA/AA lure. The addition of TA/AA significantly increased moth catches when combined with the 2‐PH lure. The TA/AA lure also allowed traps to catch both sexes. Catch of C. pomonella with the 2‐PH lure was comparable to the use of codlemone; however, moth catch was significantly reduced with the 2‐PH/PE lure. Optimization of these complex lures can likely further improve managers’ ability to monitor G. molesta and help to develop multispecies tortricid lures for use in individual traps.     

Monitoring oriental fruit moth (Lepidoptera: Tortricidae) with sticky traps baited with terpinyl acetate and sex pheromone

Studies in Argentina and Chile during 2010–2011 evaluated a new trap (Ajar) for monitoring the oriental fruit moth, Grapholita molesta (Busck). The Ajar trap was delta‐shaped with a jar filled with a terpinyl acetate plus brown sugar bait attached to the bottom centre of the trap. The screened lid of the jar was inserted inside the trap, and moths were caught on a sticky insert surrounding the lid. The Ajar trap was evaluated with and without the addition of a sex pheromone lure and compared with delta traps left unbaited or baited with a sex pheromone lure and a bucket trap filled with the same liquid bait. Studies were conducted in a sex pheromone‐treated orchard in Argentina and an untreated orchard in Chile. In Chile, the Ajar trap without the sex pheromone lure caught significantly fewer males, females and total moths than the bucket trap, and fewer males and more females than the sex pheromone‐baited delta trap. Total moth catch did not differ between the Ajar trap without a sex pheromone lure and the sex pheromone‐baited trap. Adding a sex pheromone lure to the Ajar trap significantly increased total moth catches to levels not different from those in the bucket trap. However, the Ajar trap with the sex pheromone lure caught significantly more males and fewer females than the bucket trap. In Argentina, the Ajar trap with or without the addition of a sex pheromone lure caught similar numbers of both sexes and total moths as the bucket trap. The sex pheromone‐baited delta trap caught <4% of the number of moths as these three traps. The bucket trap in both studies caught significantly more non‐targets than the delta and Ajar traps. Moth catches in the Ajar trap declined significantly after 2–3 weeks when the bait was not replaced.     

Monitoring codling moth (Lepidoptera: Tortricidae) with a four‐component volatile blend compared to a sex pheromone‐based blend

Monitoring adult codling moth, Cydia pomonella (L.), is a crucial component in implementing effective integrated management programmes in apple, Malus domestica Borkhausen. Use of sex pheromone lures to track male populations has been the traditional approach, but their use in orchards treated with sex pheromone for mating disruption (MD) has been problematic. Development of kairomone and kairomone–pheromone combination lures has allowed the catch of female moths and has benefited several aspects of codling moth management through improved spray timings and action thresholds. Recently, a new four‐component volatile blend (4‐K) comprised of pear ester, (E,Z)‐2,4‐ethyl decadienoate (PE), (E)‐11 4,8‐dimethyl‐1,3,7‐nonatriene, all isomers of pyranoid linalool oxide and acetic acid (AA) has been characterized that has increased female moth catch threefold versus any previous blend. Field trapping studies were conducted to compare moth catches in traps baited with 4‐K versus the use of sex pheromone, (E,E)‐8,10‐dodecadien‐1‐ol (PH) in combination with PE and AA. Trials were conducted in orchards left either untreated, or treated with PH or PH + PE. Traps baited with 4‐K and 4‐K + PH lures caught significantly more females than traps baited with PH + PE + AA lures. Traps baited with 4‐K + PH lures caught significantly more total moths than traps baited with PH + PE + AA lures in all three orchards. Adding a PH lure to traps with the 4‐K lure did not affect female catch, but significantly increased male and total moth catches. These studies demonstrate that codling moth can be trapped effectively in apple under MD without the use of sex pheromone lures. The significant increase in female codling moth catch with the 4‐K lure suggests that efforts to improve spray timings and action threshold determinations as well as mass trapping might be enhanced with this new lure.     

Combined approaches using sex pheromone and pear ester for behavioural disruption of codling moth (Lepidoptera: Tortricidae)

Attractive properties of pear ester, ethyl (E,Z)‐2,4‐decadienoate, and codlemone, (E,E)‐8,10‐dodecadien‐1‐ol, the sex pheromone of codling moth, Cydia pomonella (L.), were utilized in experiments on behavioural disruption of mating. Standard dispensers loaded with codlemone alone or in combination with pear ester (combo) were applied at 500–1000/ha. Larger (10‐fold) combo dispensers (Meso) were evaluated at a rate of 80/ha. The addition of microencapsulated pear ester, PE‐MEC, sprayed with insecticides at 30 ml/ha was also evaluated. Male moth catches in unmated female‐baited traps were lower in standard combo dispenser than in codlemone dispenser–treated plots. Female moth catch in traps baited with the combination of pear ester, codlemone and acetic acid was lower in standard combo dispenser than in codlemone dispenser–treated plots. In 12 comparative experiments spanning from 2006 to 2012, male moth catch in unmated female‐baited traps was consistently and significantly lower in combo than in codlemone dispenser–treated plots. Male catch in codlemone‐baited traps did not differ between dispenser treatments in eight studies from 2006 to 2009. These results emphasize the benefit of alternatively using traps baited with unmated females over codlemone lures for the analysis of dispenser activity. Fruit injury was significantly reduced with the addition of PE‐MEC to insecticide applications across untreated and dispenser treatments. Proportion of unmated females trapped was higher in standard combo dispenser than in codlemone dispenser–treated and untreated plots. Similarly, the proportion of unmated females caught was higher in the Meso combo dispenser than in nearby or distant codlemone dispenser–treated plots. These field studies conducted in apple over 3 years demonstrate that adding pear ester both to pheromone dispensers, either standard or Meso, and to supplementary insecticide sprays can provide a significant increase in the disruption of sexual communication, reductions in female mating and reductions in fruit injury.     

Variability in the efficacy of sex pheromone lures for monitoring oriental fruit moth (Lepidoptera: Tortricidae)

Studies were conducted in Chile and the United States to compare the attractiveness of various commercial sex pheromone lures and two experimental lures for oriental fruit moth, Grapholita molesta (Busck), in peach orchards treated with or without sex pheromone dispensers. The experimental lures contained the three‐component sex pheromone blend of G. molesta: Z‐8‐dodecenyl acetate, E‐8‐dodecenyl acetate and Z‐8‐dodecenol (Z8‐12:OH), and the sex pheromone of codling moth, Cydia pomonella (L.), (E,E)‐8,10‐dodecadien‐1‐ol, (codlemone). Commercial lures varied in their substrate, initial loading and blend ratio of components. Significant differences in male catches were found among commercial lures in orchards treated with or without sex pheromone dispensers. Experimental lures with the addition of codlemone significantly increased the catches of G. molesta using lures loaded with 0%, 1% or 5% Z8‐12:OH in the G. molesta blend compared with the same ratio of components in just the G. molesta blend. The experimental lures were significantly more attractive than all commercial lures in the untreated orchard. However, moth catch with the experimental lures in the sex pheromone‐treated orchard was only intermediate among all of the lures tested. These findings highlight the need to develop more effective and standardized lures that can be used in trap‐based monitoring programme for this important pest.     

Acetic acid lure placement within traps affects moth catches of codling moth (Lepidoptera: Tortricidae)

Previous studies have shown that the addition of an acetic acid colure (AA) to traps baited with pear ester, (E,Z)‐2,4‐ethyl‐decadienoate, and codlemone, (E,E)‐8,10‐dodecadien‐1‐ol, the sex pheromone (PH) of codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), (Combo lure) can significantly increase moth catches. A commercial AA colure was developed to be used with the Combo lure using a specialized cardboard lure holder. However, research in 2011 suggested that the addition of the AA colure placed in the holder was reducing moth catches. Studies were subsequently conducted in both North America and South America to examine the factors affecting these unexpected results. Hanging the AA colure from the inside top of the delta trap was found to be a primary factor reducing moth catches of male but not female codling moth. Significantly, more males were caught if the AA colure was placed on the sticky liner of the trap than in the holder. Laboratory and field studies found that this negative effect on moth catches lessens over time with aged AA colures that had lower emission rates. The position of the holder in the trap (upwind or downwind) relative to the direction where moths approached was not a significant factor affecting moth catch with the AA colure. However, the spacing of the lures on the holder was an important factor with significantly higher male catches with lures 5.5 cm apart and the AA lure above the Combo lure than with lures 1.5 cm apart and the Combo lure above the AA lure. Similarly, pinning the Combo lure to the roof of the trap was more effective than the use of the holder with the AA lure on the liner. Standardization of lure placement will be important to fully utilize the use of bisexual, multilure monitoring systems for codling moth and likely for other pests.     

Monitoring codling moth (Lepidoptera: Tortricidae) in orchards treated with pear ester and sex pheromone combo dispensers

Monitoring codling moth, Cydia pomonella (L.), with its sex pheromone (E,E)‐8,10‐dodecadien‐1‐ol (codlemone) alone or in combination with plant volatiles (PH‐plant volatile lures) with and without the addition of an acetic acid (AA) lure was compared in apple and walnut orchards treated with PVC Cidetrak^® dispensers (CM‐DA Combo) loaded with 60 mg pear ester, ethyl (E, Z)‐2,4‐decadienoate (PE) and 185 mg codlemone. Lures were also evaluated in untreated apple and walnut orchards and apple orchards treated with Cidetrak^® dispensers (CM) loaded with 120 mg codlemone. Traps with codlemone lures caught more moths than PE plus AA but similar numbers as traps with the PH‐PE lure in untreated apple and walnut orchards. The PH‐PE outperformed codlemone lures in apple orchards treated with CM dispensers. Codlemone outperformed PH‐PE lures in apple but not in walnut orchards treated mid‐season with CM‐DA Combo dispensers. Combining AA with PE significantly increased moth catch and together they performed similarly to the PH‐PE lure in all dispenser treatments in apple orchards. However, adding AA with the PH‐PE lure did not increase moth catches. The addition of AA to any of the lures tested except codlemone alone significantly increased the catch of females. Adding AA to either PE or the PH‐PE lure created a similarly attractive lure in orchards treated with CM‐DA Combo dispensers. Combining (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT) with codlemone in a combinational lure plus AA performed as well as any lure tested in apple orchards treated with CM‐DA Combo dispensers. Combinational lures loaded with either (E,E)‐farnesol, (E)‐β‐farnesene or DMNT performed significantly better than the PH‐PE lure in apple orchards treated with CM‐DA Combo dispensers only in the first generation. Both PH‐DMNT and PH‐farnesol lures were comparable to PH‐PE, except that the PH‐farnesol lure was less attractive to female moths.     

Development of 2‐phenylethanol plus acetic acid lures to monitor obliquebanded leafroller (Lepidoptera: Tortricidae) under mating disruption

We evaluated the effectiveness of 2‐phenylethanol (PET) in combination with acetic acid (AA) as a binary lure for monitoring male and female obliquebanded leafroller, Choristoneura rosaceana (Harris). Studies were conducted in apple, Malus domestica Borkhausen, orchards treated with or without sex pheromone dispensers for mating disruption (MD). Open polypropylene vials, closed membrane cups, and rubber septa loaded with AA and/or PET in varying amounts were first evaluated in a series of trapping experiments. Membrane cups loaded with 800 mg of PET were as effective as 10‐mg septa, but longer lasting, and were comparable to the open vials. A membrane cup AA lure was effective in tests, but further work is needed to increase its release rate and extend its activity. Catches of codling moth, Cydia pomonella (L.), and C. rosaceana were unaffected by combining PET with (E,E)‐8,10‐dodecadien‐1‐ol, the sex pheromone of codling moth, pear ester, (E,Z)‐2,4‐ethyl‐decadienoate and AA lures. Adding (E)‐4,8‐dimethyl‐1,3,7‐nonatriene to this blend to enhance codling moth catch significantly reduced catches of C. rosaceana. PET + AA was a more attractive binary lure than AA plus phenylacetonitrile (PAN) for C. rosaceana. The addition of PET or PAN to traps already baited with the sex pheromone of C. rosaceana significantly reduced male catches. Traps baited with PET + AA placed in blocks not treated with MD caught significantly fewer C. rosaceana than traps baited with sex pheromone. In comparison, sex pheromone‐baited traps in MD blocks caught ≤1 male moth per season which was significantly lower than total moth (>10) or female moth (≥3) catch in these blocks with PET + AA. A high proportion (>70%) of trapped females were mated in both untreated and MD‐treated orchards. Further refinement of this binary, bisexual lure using membrane cup technology may allow the establishment of action thresholds and improve management timings for C. rosaceana.     

Importance of trap liner adhesive selection for male moth catch (Lepidoptera: Tortricidae) with bisexual attractants

Studies compared moth captures of three pests (Lepidoptera: Tortricidae) of apple, Malus domestica Borkhausen, in delta traps using removable liners coated with either a sticky gel (SG) or a hot‐melt pressure sensitive (HMPS) adhesive. Laboratory and field studies with Cydia pomonella (L.), Choristoneura rosaceana (Harris) and Grapholita molesta (Busck) demonstrated that traps with either liner, baited with a pair of virgin females catch males, but at significantly different levels. In the field, male moth captures in traps with the HMPS liner were significantly greater than in traps with the SG liner for C. rosaceana, and G. molesta; but not for C. pomonella. Similar results were observed in laboratory studies using flight tunnels. Additional studies demonstrated that this difference in moth captures between liners was not due to levels of female mortality, but instead was correlated with the occurrence of the female's ventral abdominal surface becoming stuck in the adhesive. Studies showed that a significantly greater proportion of females of all species had their ventral abdomen stuck in the SG than HPMS adhesive on day 1, but only G. molesta and C. rosaceana on day 3. In addition, the tackiness of the two adhesives affected moth movement on the liner with males and females of all species moving farther on liners with SG than HMPS adhesive. A greater proportion of female G. molesta and C. pomonella were either stuck supined or laterally on the SG than HMPS adhesive, and females in this position captured as many males as when prone and unstuck on the liner. Our studies demonstrate that adhesives can secondarily influence male moth captures on trap liners when used with bisexual attractants, and that adhesive type should be considered when developing action thresholds.     

Traps and Baits for Luring <Emphasis Type="Italic">Grapholita molesta</Emphasis> (Busck) Adults in Mating Disruption-Treated Apple Orchards

Grapholita molesta (Busck) is one of the main pests in apple crops in Brazil, where it is controlled by mating disruption (MD) with the use of the synthetic sex pheromone. However, sex-pheromone-based monitoring is not effective in MD-treated areas and may result in losses in production. This work has defined a trap model and a bait for luring G. molesta adults in MD apple orchards. The experiments were conducted in commercial apple orchards located in São Joaquim, SC, Brazil. Three trap models—McPhail, Pot, and Ajar—and three baits—grape juice (25%) (GJ), sugarcane molasses (25%) (SM), and a solution containing brown sugar (8.69%) and terpinyl acetate (0.05%) (TAS)—were assessed for luring G. molesta adults in areas subjected to the mating disruption. The assessments were performed weekly by collecting the insects caught in the traps. In addition, time needed to replace traps was also assessed, as well as the selectivity of the trap/bait set. In the laboratory, G. molesta adults were sexed, and the females were dissected to confirm reproductive status. We discuss our results and sugarcane molasses (25%) captured the least number of G. molesta adults regardless of the tested traps. The Ajar/TAS, Pot/TAS, and McPhail/GJ captured the largest number of G. molesta adults. The Ajar/TAS was the most selective and easier to handle. TAS was efficient in catching G. molesta until 14 days after preparation of the solution. Ajar/TAS has potential to be used in the monitoring of G. molesta in apple orchards.     

Female‐targeted attractant containing pear ester for Synanthedon myopaeformis

When testing pear ester (ethyl‐2,4‐decadienoate) + acetic acid (PEAA) lures to catch codling moths, Cydia pomonella (L.) (Lepidoptera: Tortricidae), in Hungary, significant catches of the apple clearwing moth, Synanthedon myopaeformis (Borkhausen) (Lepidoptera: Sesiidae), were also recorded. This sesiid is one of the most important pests of apple in Europe. Pear ester plus acetic acid lures were attractive to S. myopaeformis no matter whether the two compounds were provided in separate dispensers or mixed together in a single dispenser, and a large percentage (40–80%) of the clearwing moths caught were females. In all cases, traps baited with binary combinations of PEAA caught far more than traps baited with either of the compounds presented alone. Traps with PEAA lures in some tests caught (females and males together) up to ca. 20% of the catch in traps baited with the synthetic apple clearwing moth sex attractant (all males). Consequently, the PEAA lure shows potential for future practical applications as a female‐targeted lure. To our knowledge, this is the first report of attractiveness of a lure containing pear ester for non‐tortricid Lepidoptera. Our finding suggests that the compound may be exploited as a host location stimulus by a wider array of insects than was indicated previously.     

Traps baited with pear ester and acetic acid attract both sexes of Hedya nubiferana (Lepidoptera: Tortricidae)

This study was initiated with the objective of studying field responses of the green budworm moth, Hedya nubiferana (Haworth) (Lepidoptera: Tortricidae), to pear ester [PE; ethyl (E,Z)‐2,4‐decadienoate] and acetic acid (AA) with the aim of developing a lure attractive also for females. In the overwhelming majority of tests, traps baited with the PEAA lure (the combination of both PE and AA) caught more than traps baited with either of the constituents presented alone. PEAA lures were attractive to H. nubiferana no matter whether the two compounds were provided in separate dispensers or mixed together in a single one, and a large percentage (up to 71%) of trap catch consisted of females. Traps with PEAA lures caught (females plus males) on an average 30% of the catches in traps baited with the synthetic green budworm moth sex pheromone (only males). This suggested that the new PEAA lure had a trapping performance comparable with that of pheromone traps, which latter are used by farmers today. Consequently, the PEAA lure showed potential for future practical applications as a female‐targeted lure for H. nubiferana. To our knowledge, this is the first well‐documented report on the attraction of PEAA lure for a tortricid species other than codling moth.     

Evaluation of attractants and traps for monitoring small banded pine weevil Pissodes castaneus

This study aimed to develop a semiochemical‐baited trapping system to monitor the populations of small banded pine weevil, Pissodes castaneus, a serious pest in Pinus sylvestris young stands that are weakened by biotic and abiotic factors. The scope of the work included the development of a dispenser for compounds (ethanol and α‐pinene) emitted by P. sylvestris and the pheromones of P. castaneus: grandisol and grandisal. Additionally, the effectiveness of beetle catches in different types of traps (unitrap, cross‐unitrap and long and short pipe traps) baited with a dispenser was assessed. The olfactometric studies showed that most of the newly hatched beetles that had not fed were attracted by a mixture of grandisol and grandisal. However, in the group of feeding beetles, half were attracted by a mixture of ethanol and α‐pinene. These results indicated that both pheromones and α‐pinene plus ethanol should be useful for capturing P. castaneus beetles. In the field trials, the highest efficiency was found in baited unitraps that caught up to several hundred P. castaneus beetles, while the baited cross‐unitraps caught up to a few dozen beetles. No insects were found in either type of baited pipe trap or in any of the unbaited control traps. The baited unitraps and cross‐unitraps also collected, with varied intensity, Hylobius abietis beetles, a serious pest of reforestations. These results indicate the possibility of using a unitrap baited with a 4‐component attractant for monitoring P. castaneus in integrated pest management for the protection of young forests.     

Developing female removal for Cydia pomonella (Lepidoptera: Tortricidae) in organic pear in the USA and Italy

Seventeen trials were conducted using traps baited with kairomone-based lures to evaluate female removal (FR) as an effective management tactic for codling moth, Cydia pomonella, L., in organic pear, Pyrus communis L., production in Italy and USA during 2019–2020. Studies included paired plots (0.4–1.4 ha) treated with or without 60 traps ha⁻¹ in cultivars Bartlett and Abate Fétel. Paired plots were also treated together with or without mating disruption (MD) and with similar spray programmes. Three-, four-, and five-component lures were used with several trap types: green, clear or green/white bucket traps and orange delta traps. The three-component lure consisted of (E,E)-8,10-dodecadien-1-ol (sex pheromone, PH), (E,Z)-2,4-ethyl decadienoate (pear ester, PE) and acetic acid (AA); the four-component lure was PE, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), 6-ethenyl-2,2,6-trimethyloxan-3-ol (pyranoid linalool oxide, LOX), and AA, and the five-component lure had PH added. Preliminary studies were also conducted to evaluate the trapping efficacy of non-saturating bucket traps. A clear bucket trap baited with PE/DMNT/LOX + AA captured 97-fold more codling moth females than an orange delta trap baited with PH/PE. However, female captures did not differ between traps when both were baited with the four-component lure. Fruit injury from codling moth was significantly reduced with the implementation of FR in both pear production regions. At harvest, mean fruit protection in the USA studies was 65% and 27% in Italy. This difference was likely associated with the four-component lure being less effective in Italy than in the USA. Nevertheless, results demonstrate that FR can be a useful approach to remove females immigrating into orchards and as a new tactic to reduce pest pressure in selected areas of orchards allowing both MD and organic insecticide programmes to be more effective. Further studies should investigate the cost-benefit of matching the intensity of FR to variable pest pressures.     

Foraging niche separation of social wasps in an invaded area: Implications for their management

Foraging niche separation may be a mechanism to promote coexistence of two competing species by concentrating intraspecific competition relative to interspecific competition. The present study investigated foraging behaviour and microhabitat use of two coexisting species of invasive social wasps, Vespula germanica and Vespula vulgaris, when foraging for two different food resources. Also, we tested the attractiveness of traps baited with a synthetic lure for those two species. We found that V. germanica wasps prefer to forage at ground level regardless of the resource, while V. vulgaris prefers protein resources at the shrubland level given a choice between a protein bait at ground or at shrubland level. However, when baited with the synthetic lure, the species caught was not affected by the height at which traps were placed. That is, in a no choice scenario, the traps were sufficiently attractive to lure both species of wasps to both microhabitats (ground and shrubland levels). Thus, our results support the existence of spatial niche differentiation at least in protein foraging and suggest that the synthetic lure evaluated could be used to trap both species of Vespula wasps present in Argentina. These results could help to improve management strategies of these social wasps in an invaded area.     

Improving monitoring tools for spotted wing drosophila,Drosophila suzukii

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) were trapped in the field using colored plastic sphere traps coated with insect Tangle‐trap. Red and black spheres captured significantly more D. suzukii than white spheres. Translucent deli‐cup traps deployed in cherry orchards and baited with yeast, the Alpha Scents lure, or the Scentry lure captured significantly more flies than the Trécé lure and Suzukii bait; all attractants had poor selectivity for D. suzukii. No‐choice evaluations of attractants conducted in field cages corroborated the cherry orchard field study, though translucent deli‐cup traps provisioned with the yeast bait captured significantly more flies than those baited with the Alpha Scents lure. Red sphere traps baited with the Scentry lure captured 3–6× more flies than the deli‐cup trap baited with the same lure, and 3–4× more flies than the deli‐cup trap baited with yeast bait, demonstrating that a trap integrating both visual and olfactory cues is a superior tool for monitoring D. suzukii. Moreover, this simple sticky, dry trap design requires far less labor and maintenance than does a liquid‐based deli‐cup trap.     

Efficacy of the pheromone (3Z)‐lactone and the host kairomone (3Z)‐hexenol at detecting early infestation of the emerald ash borer,Agrilus planipennis

The invasive emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a major pest of ash trees, Fraxinus spp., in its introduced range in North America. Field studies were conducted to quantify the efficacy of traps baited with kairomone and pheromone lures for early detection of A. planipennis infestation. A trapping experiment demonstrated that green traps baited with the kairomone (3Z)‐hexenol detected at least one adult A. planipennis in 55.3% of plots with ‘nil to low’‐density infestations and in 100% of plots with ‘moderate to high’‐density A. planipennis infestations. Mean trap captures increased significantly with increasing infestation density. In terms of the optimal number of traps per plot, when one (3Z)‐hexenol‐baited trap was placed per plot, the trap detected populations in 62% of the plots with ‘low to moderate’‐density infestations through branch sampling. Detectability was increased to 82% when two traps were placed per plot. Finally, addition of female‐produced (3Z)‐lactone pheromone to traps significantly increased detection rates at both the trap and plot level, as compared with traps baited with the host volatile, (3Z)‐hexenol, alone (88 vs. 60%, respectively). Our results are the first to demonstrate the efficacy of baited green sticky traps for detecting low‐density A. planipennis infestations, particularly when the (3Z)‐lactone pheromone is used. This combination is therefore recommended for development of early‐detection protocols against A. planipennis.     

Monitoring codling moth (Lepidoptera: Tortricidae) in sex pheromone-treated orchards with (E)-4,8-dimethyl-1,3,7-nonatriene or pear ester in combination with codlemone and acetic acid

Traps baited with ethyl (E,Z)-2,4-decadienoate (pear ester) or (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) in two- or three-way combinations with the sex pheromone (E,E)-8,10-dodecadien-1-ol (codlemone) and acetic acid (AA) were evaluated for codling moth, Cydia pomonella (L.). All studies were conducted in apple orchards, Malus domestica Borkhausen, treated with sex pheromone dispensers during 2010. Septa were loaded with codlemone, DMNT, and pear ester individually or codlemone with either DMNT or pear ester together (combo lures). Polyethylene vials loaded with AA were added as a co-lure. Residual analyses of field-aged combo lures and weight loss of the AA co-lure were conducted. AA vials lost 50-150 mg wk(-1). Weekly weight loss was not affected by field aging, but was closely correlated with the daily mean temperature. Pear ester was released from septa at a slightly higher but nonsignificant rate than codlemone. DMNT was released at a significantly higher rate than codlemone, and lures were effective for 4 wk. The addition of codlemone to traps baited with either host plant volatile plus AA had either no effect or significantly increased total moth catches. The addition of AA significantly increased the catch of female moths with either combo lure. Total moth catches in traps baited with pear ester or DMNT combo lures and AA did not differ and were either significantly higher or similar to the pear ester combo lure. These data suggest that codling moth may be more effectively monitored in sex pheromone-treated orchards with multi-component lures, including codlemone, AA, and host plant volatiles.     

Real-time monitoring of oriental fruit moth,Grapholita molesta,populations using a remote sensing pheromone trap in apple orchards

A fusion of information technology (IT) and sex pheromone monitoring provides a remote sensing IT-pheromone trap to monitor Oriental fruit moth, Grapholita molesta, populations in apple orchards. Once a male of G. molesta is attracted to its sex pheromone lure in the trap, an infrared sensor installed at the funnel-shaped orifice generates an electric signal. The signal is processed in a central processor and then transferred to an internet site via a code division multiple access protocol. The signal also contains information about when each male is caught. Daily trapping information from different localities is archived in a website. The accuracy of IT-pheromone traps in detecting male catches was shown by a high correlation (r = 0.956) between the generated IT signals and actual numbers of males caught in the trap in apple orchards. Using this IT-pheromone trap, G. molesta in apple orchards was monitored for one year. These data were compared with monitoring data obtained from a conventional wing type-based sticky trap containing the identical sex pheromone lure. Both showed four characteristic adult peaks from April to September and were significantly correlated (r = 0.695). IT-pheromone traps also gave real-time signals of male catches in the field. These real-time signals of male catches showed a characteristic diel attraction rhythm from 4 pm to midnight. The diel rhythm of the male response to the sex pheromone started earlier in the evening in the spring season compared to mid and late seasons. This study provides a novel sex pheromone trap for G. molesta to monitor its population in field conditions in real-time without visiting or counting. The field monitoring data can be accessed any time through a designated internet website.