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.     

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.     

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.     

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.     

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.     

Monitoring oriental fruit moth and codling moth (Lepidoptera: Tortricidae) with combinations of pheromones and kairomones

Experiments were conducted in North and South America during 2012–2013 to evaluate the use of lure combinations of sex pheromones (PH), host plant volatiles (HPVs) and food baits in traps to capture the oriental fruit moth, Grapholita molesta (Busck), and codling moth, Cydia pomonella (L.), in pome and stone fruit orchards treated with sex pheromones. The combination of the sex pheromone of both species (PH combo lure) significantly increased G. molesta and marginally decreased C. pomonella captures as compared with captures of each species with either of their sex pheromones alone. The addition of a HPV combination lure [(E,Z)‐2,4‐ethyl decadienoate plus (E)‐β‐ocimene] or acetic acid used alone or together did not significantly increase the catch of either species in traps with the PH combo lure. The Ajar trap baited with terpinyl acetate and brown sugar (TAS bait) caught significantly more G. molesta than the delta trap baited with PH combo plus acetic acid in California during 2012. The addition of a PH combo lure to an Ajar trap significantly increased catches of G. molesta compared to the use of the TAS bait or PH combo lure alone in 2013. Female G. molesta were caught in TAS‐baited Ajar traps at similar levels with or without the use of additional lures. Ajar traps baited with the TAS bait alone or with (E)‐β‐ocimene and/or PH combo lures caught significantly fewer C. pomonella than delta traps with sex pheromone alone. Ajar traps with 6.4‐mm screened flaps caught similar numbers of total and female G. molesta as similarly baited open Ajar traps, and with a significant reduction in the catch of non‐targets. Broader testing of HPV and PH combo lures for G. molesta in either delta or screened or open Ajar traps is warranted.     

Effect of anti‐hail nets on Cydia pomonella behavior in apple orchards

Over the last 10 years, the use of nets to protect pome fruit from hailstorms has increased. In this study, we investigated the effect of these nets on the behavior of the codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), a major pest of apple, Malus domestica Borkh. (Rosaceae). Experiments were carried out in net‐covered and uncovered apple orchards treated with conventional insecticides. The number of codling moth males caught in pheromone‐ and virgin female‐baited traps was significantly reduced in net‐covered compared to uncovered plots. In addition, inhibition of mating by the net was demonstrated by significant reductions in mating of tethered virgin females. Fruit injury was consistently lower in net‐covered plots vs. uncovered plots. Because of the reductions in male trap catch, the reduced female mating frequency, and the lower level of damage, we conclude that flat anti‐hail nets have a disruptive effect on the reproductive behavior of the codling moth.     

Long‐term evaluation of field‐wide oriental beetle (Col., Scarabaeidae) mating disruption in blueberries using female‐mimic pheromone lures

The oriental beetle, Anomala orientalis (Waterhouse) (Col., Scarabaeidae), is the most important root‐feeding pest of blueberries and turfgrass in New Jersey, USA. Previous studies showed that mating disruption is a feasible option for oriental beetle management; however, assessing its efficiency can be challenging, and little is known on its long‐term effects. Accordingly, we conducted studies to investigate low‐dose pheromone lures equivalent to oriental beetle females (i.e. female mimics) as easy‐to‐use indicators of mating disruption success, determine the distance at which oriental beetle males respond to female‐mimic lures and assess the long‐term (3‐year) effects of mating disruption on oriental beetle populations in entire blueberry fields. Our studies showed that rubber septa baited with 0.3 μg of the oriental beetle sex pheromone (Z)‐7‐tetradecen‐2‐one attract similar numbers of males as compared with virgin females and can thus be used as a female mimic. The range of attraction of this lure was found to be also similar to virgin females and <30 m. In blueberries, mating disruption provided 87% inhibition of oriental beetle populations (trap shutdown) over a 3‐year period. Oriental beetle male captures in disrupted fields were threefold higher along the field edges than in the field interiors, indicating movement of males from nearby areas into the pheromone‐treated fields. In addition, mating disruption reduced male attraction to female‐mimic lures by 93% in all 3 years and reduced the number of larvae in sentinel potted plants in 1 of 2 years. These results show for the first time that mating disruption provides consistent long‐term field‐wide control of oriental beetle populations and that female‐mimic pheromone lures can be used as a new tool to assess oriental beetle mating disruption success.     

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.     

Multiple mating of male and female codling moth (Lepidoptera: Tortricidae) in apple orchards treated with sex pheromone

Studies were conducted with codling moth, Cydia pomonella L., to evaluate the mating status of male and female moths in apple, Malus domestica (Borkhausen), orchards treated with and without sex pheromone dispensers. Laboratory studies first examined the effect of multiple mating of male and female moths on female fecundity and egg fertility. Females that had mated three times had a significantly higher fecundity than singly mated moths. Sequential mating by male moths had no effect on the fecundity of female moths or egg fertility. However, male moth age did impact female fecundity, with significantly fewer eggs laid after mating with virgin 1- versus 3-d-old males. The mean size of the first spermatophore transferred by males was significantly larger than all subsequent spermatophores. Classifying spermatophores based on size was used in field sampling to categorize the mating status of the female's partner. The proportion of mated females with small spermatophores (partner had previously mated) was significantly higher in treated versus untreated orchards. The proportion of female moths caught in traps baited with pear ester that were virgin was low (相似文献   

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.     

Is lack of mating competitiveness in spring linked to mating asynchrony between wild and mass‐reared codling moths from an operational sterile insect programme?

Mating competitiveness and pheromone trap catches of mass‐reared, male codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), from the Osoyoos, British Columbia, Canada, mass‐rearing facility operated by the Okanagan‐Kootenay Sterile Insect Release Board, were compared to wild males using mark–release–recapture field experiments in spring, summer, and autumn at Summerland, British Columbia. In spring, significantly more wild diapause males mated with tethered, wild females than did non‐irradiated (0 Gy) or irradiated (100 or 250 Gy) non‐diapause, mass‐reared males. A lower dose of radiation did not improve mating competitiveness, nor catches of mass‐reared males released in spring. Median mating time for wild males was approximately 45 min earlier than mass‐reared males with most wild males (70.5%) mating before sunset and mass‐reared males mating at or shortly after sunset in spring. Superior mating competitiveness of wild males in spring was mirrored by greater recapture rates in pheromone‐baited traps. In summer, mating competitiveness of mass‐reared moths improved relative to wild males and there was a significant inverse relationship between radiation dose (0, 100, and 250 Gy) and competitiveness of mass‐reared males. In autumn, untreated, wild males were significantly more responsive to pheromone traps than non‐diapausing mass‐reared males receiving 250 Gy of radiation. Mass‐reared males, subjected to diapause‐inducing conditions as larvae and emerged from diapause before this irradiation treatment, were recaptured significantly more often than similarly irradiated, non‐diapause, mass‐reared males, but not more than untreated, diapause wild males. We hypothesize that differences between wild and mass‐reared males in daily timing or speed of responses to natural or synthetic pheromone sources under montane weather patterns typical of spring in British Columbia may partially explain poor activity of sterile males, and low sterile : wild overflooding ratios during spring when measured using pheromone traps by the sterile insect release programme in British Columbia.     

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.     

Female moths of cotton bollworm (Lepidoptera: Noctuidae) captured by waterbasin traps baited with synthetic female sex pheromone

Cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), is one of the most important pest insects in cotton fields in China. Female moths were captured by waterbasin traps with a synthetic female sex pheromone blend in cotton fields over three years. The blend contained (Z)‐11‐hexadecenal and (Z)‐9‐hexadecenal with a ratio of 97:3. Each pheromone dispenser was impregnated with 2.0 mg of pheromone blend and 0.2 mg of antioxidant dissolved with 0.1 mL of hexane, and there was a control dispenser with a similar amount of antioxidant and solvent only. Waterbasin traps were deployed in three configurations in the fields. ‘A’ was pheromone traps only, ‘B’ was both pheromone and control traps, ‘C’ was control traps only. (i) In four plots of ‘A’, the average weekly female catch was 1.5, and more females were captured by centrally located pheromone traps, (ii) In three plots of ‘Brsquo;, control traps also captured female as well as male moths, but average weekly female catches of control traps was significantly lower than that in pheromone‐baited traps. (iii) There were significant linear relationships between the average weekly female catch and the corresponding layer in pheromone‐baited traps in both ‘A’ and ‘B’ plots, and in quadratic equations in control in ‘B’ plots. (iv) With the increase of the interval of traps, average weekly female catches per trap increased but average weekly female catches per hectare decreased. (v) Among the female moths captured by pheromone traps, 88.3% were mated female moths which each containing 1.46 spermatophores, while in control traps 86.9% of the mated female moths had 0.90 spermatophores. There was a significant difference between the average numbers of spermatophores of mated females in pheromone traps and in controls.     

Addition of terpenoids to pear ester plus acetic acid increases catches of codling moth (Lepidoptera: Tortricidae)

Field studies were conducted to evaluate new kairomone blends in combination with pear ester (E,Z)‐2,4‐ethyl decadienoate (PE) and acetic acid (AA) for their attraction of male and female codling moth, Cydia pomonella (L.), in apple, Malus domestica Borkhausen. The addition of decanal to either AA or PE alone significantly increased total and female moth catches. However, the addition of decanal did not improve the attraction of PE + AA. The addition of either the pyranoid (PyrLOX) or furanoid (FurLOX) linalool oxide but not linalool (LOL) increased moth catches with PE but did not increase catches with PE + AA. Similarly, the addition of PyrLOX plus decanal did not improve PE + AA. The addition of (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT) to either AA, PE + AA or PE + AA+decanal did not significantly increase moth catches. However, the addition of PyrLOX to traps with PE + AA and DMNT (4‐component lure) significantly increased moth catches compared with PE + AA alone or any of the ternary blends of these volatiles. Females accounted for 60%–80% of the total catch with this 4‐component lure. The 4‐component blend with PyrLOX was a more attractive lure than similar blends that substituted LOL, or a binary blend of LOL and FurLOX for PyrLOX. The 4‐component blend caught nearly fourfold more total and female moths than the purported attractant N‐butyl sulphide when it was used in combination with PE + AA. These results indicate that significant improvements in monitoring, mating disruption and mass trapping of codling moth are possible. Further studies are needed to assess the new attractive blend's effectiveness in combination with sex pheromone lures and to evaluate whether other host plant volatiles can be added or substitute for DMNT or LOX when used in combination with PE + AA.     

Optimization of pheromone dosage for gypsy moth mating disruption

The effect of aerial applications of the pheromone disparlure at varying dosages on mating disruption in low‐density gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), populations was determined in field plots in Virginia, USA during 2000 and 2002. Six dosages [0.15, 0.75, 3, 15, 37.5, and 75 g active ingredient (AI)/ha] of disparlure were tested during the 2‐year study. A strongly positive dose–response relationship was observed between pheromone dosages and mating disruption, as measured by the reduction in male moth capture in pheromone‐baited traps and mating successes of females. Dosages of pheromone 15 g AI/ha (15, 37.5, and 75 g AI/ha) reduced the mating success of females by >99% and significantly reduced male moth catches in pheromone‐baited traps compared to untreated plots. Pheromone dosages <15 g AI/ha also reduced trap catch, but to a lesser extent than dosages 15 g AI/ha. Furthermore, the effectiveness of the lower dosage treatments (0.15, 0.75, and 3 g AI/ha) declined over time, so that by the end of the study, male moth catches in traps were significantly lower in plots treated with pheromone dosages 15 g AI/ha. The dosage of 75 g AI/ha was initially replaced by a dosage of 37.5 g AI/ha in the USDA Forest Service Slow‐the‐Spread (STS) of the Gypsy Moth management program, but the program is currently making the transition to a dosage of 15 g AI/ha. These changes in applied dosages have resulted in a reduction in the cost of gypsy moth mating disruption treatments.     

Factors influencing the effectiveness of an attracticide formulation against the Oriental fruit moth, Grapholita molesta

An attracticide formulation, LastCall?OFM, was tested against the Oriental fruit moth Grapholita molesta (Busck) (Lepidoptera: Tortricidae) in replicated small plot field trials in apple, Malus domestica (Borkhausen), orchards in South‐eastern Pennsylvania, USA. Attracticide treatments were applied using a calibrated hand pump, and treated plots were compared to similar untreated plots. Male moth activity was monitored using virgin female‐baited traps, and the potential for reduction in mating activity was assessed using sentinel virgin females. A comparison of application rates showed that 1500 droplets per ha of the attracticide formulation was as effective as 3000 droplets per ha, and both application rates reduced captures in synthetic pheromone‐baited traps for prolonged periods. Droplets placed either at high or low positions within the canopy significantly reduced trap capture and mating with sentinel females. In addition, the only sentinel females that mated in the treated plots were located in the untreated portion of the tree canopy. Mate finding behaviour was equally disrupted by formulations with and without insecticide. Therefore, under the test conditions, the mechanism by which the attracticide formulation worked was by disruption of male orientation, and not by the removal of males due to insecticide poisoning. Two field cage experiments tested the impact of population density on the competitiveness of the attracticide formulation compared to virgin females. A significant proportion of males were captured in female‐baited traps at the highest female‐to‐droplet ratio tested. Equal proportions of males were captured in attracticide‐baited traps at male moth densities of 10, 20, 40, and 80 males per cage. These results clarify some of the factors influencing the effectiveness and possible mechanisms of an attracticide management tactic against the Oriental fruit moth.     

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.