Biology and natural enemies of Cydalima perspectalis in Asia: Is there biological control potential in Europe?

The box tree moth, Cydalima perspectalis (Walker) (Lepidoptera: Crambidae), a native pest of box trees (Buxus spp.) in Asia, was first detected in Germany and the Netherlands in 2007 and has since rapidly spread throughout Europe causing severe damage to ornamental and native box trees. To date, sustainable control strategies for C. perspectalis in Europe are lacking, primarily owing to the inadequate information regarding the biology and the ecology of this recent invader. Several studies conducted in Asia, however, may provide important information for the development of management strategies against C. perspectalis, which are urgently needed to preserve the natural box tree forests in Europe. The current literatures on the biological characteristics, host plants, phenology, distribution and control options of the box tree moth in Asia are reviewed, preliminary data on the parasitism of C. perspectalis in Europe are provided, and options for sustainable long‐term solutions for the management of the invasive pest in Europe are discussed.     

Oviposition preference and larval development of the invasive moth Cydalima perspectalis on five European box‐tree varieties

The box‐tree pyralid Cydalima perspectalis (Walker 1859) (Lepidoptera: Pyralidae), native to Eastern Asia, is a newly introduced species causing severe damage to box‐trees (Buxus sp.) in private and public gardens as well as in semi‐natural box‐tree forests in Central Europe. It is so far not known whether different box‐tree subspecies (or varieties) are similarly affected by this invasive moth. In a choice experiment offering branches of five different box‐tree varieties as oviposition sites, we found a preference of female moths for laying their egg clusters on the variety ‘Rotundifolia’, while other varieties were less frequently considered. The preference for ‘Rotundifolia’, the variety with the largest leaves in the tests, remained when intervariety differences in foliar area (mean leaf size × number of leaves) were taken into account. Feeding larvae on leaves of either of the five box‐tree varieties revealed a significant effect of the seasonal generation of C. perspectalis on the growth rate of individuals but no influence of the box‐tree variety. Larvae from the spring generation show the highest growth rate, those from the summer generation a moderate and those from the autumn generation the lowest growth rate. The moths used in the experiments may belong to the 10th to 12th generation present in Europe. The time elapsed since their introduction may be too short for an optimal adaptation to the partly novel diet encountered by the invasive moth.     

Temperature‐dependent phenology and growth potential of the Andean potato tuber moth,Symmetrischema tangolias (Gyen) (Lep., Gelechiidae)

The Andean potato tuber moth, Symmetrischema tangolias (Gyen) [Lepidoptera, Gelechiidae], is an economically important pest of potato (Solanum tuberosum L.) in the mid‐elevated Andean region and an invasive pest of partially global importance. Determination of the pest's population life table parameters is essential for understanding population development and growth under a variety of climates and as part of a pest risk analysis. The development, mortality and reproduction were studied in two pest populations (from Peru and Ecuador) in which cohorts of each life stage were exposed to different constant temperatures ranging from 10°C to 28°C. Using the Insect Life Cycle Modeling software, nonlinear equations were fitted to the data and an overall phenology model established to simulate life table parameters based on temperature. The temperature‐dependent development curve was statistically well described for eggs by Ratkowsky's model and for larvae and pupae by Taylor's model. Variability in development time among individuals independent of temperature was significantly described by a log‐logistic model. Temperature effects on immature mortality were described using different nonlinear models. Optimal temperature for survival was between 14° and 17°C. Temperature effects on adult senescence and oviposition time were described by simple exponential models; within‐group variability was described by a Weibull distribution function. Fecundity per female due to temperature followed a nonlinear model indicating maximum reproduction at ~17°C. The established model revealed good convergence with historical life tables established at fluctuating temperatures. The results confirm that S. tangolias is more adapted to cooler temperature than the common potato tuber moth, Phthorimaea operculella (Zeller). S. tangolias develops at temperatures within the range of 8–28.8°C with a maximum finite rate of population increase (=1.053) at 21°C. The established process‐based physiological model can be used globally to simulate life table parameters for S. tangolias based on temperature and should prove helpful for evaluating the potential establishment risk and in adjusting pest management programmes.     

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.     

A chromosome‐level genome assembly reveals the genetic basis of cold tolerance in a notorious rice insect pest,Chilo suppressalis

The rice stem borer, Chilo suppressalis, is one of the most damaging insect pests to rice production worldwide. Although C. suppressalis has been the focus of numerous studies examining cold tolerance and diapause, plant–insect interactions, pesticide targets and resistance, and the development of RNAi‐mediated pest management, the absence of a high‐quality genome has limited deeper insights. To address this limitation, we generated a draft C. suppressalis genome constructed from both Illumina and PacBio sequences. The assembled genome size was 824.35 Mb with a contig N₅₀ of 307 kb and a scaffold N₅₀ of 1.75 Mb. Hi‐C scaffolding assigned 99.2% of the bases to one of 29 chromosomes. Based on universal single‐copy orthologues (BUSCO), the draft genome assembly was estimated to be 97% complete and is predicted to encompass 15,653 protein‐coding genes. Cold tolerance is an extreme survival strategy found in animals. However, little is known regarding the genetic basis of the winter ecology of C. suppressalis. Here, we focused our orthologous analysis on those gene families associated with animal cold tolerance. Our finding provided the first genomic evidence revealing specific cold‐tolerant strategies in C. suppressalis, including those involved in glucose‐originated glycerol biosynthesis, triacylglycerol‐originated glycerol biosynthesis, fatty acid synthesis and trehalose transport‐intermediate cold tolerance. The high‐quality C. suppressalis genome provides a valuable resource for research into a broad range of areas in molecular ecology, and subsequently benefits developing modern pest control strategies.     

The potential for Entomophaga maimaiga to regulate gypsy moth Lymantria dispar (L.) (Lepidoptera: Erebidae) in Europe

Gypsy moth, Lymantria dispar L., is one of the most important pests of deciduous trees in Europe. In regular cycles, it causes large‐scale defoliation mostly of oak, Quercus spp., forests. Government authorities in the most infested countries in Europe conduct large‐scale applications of pesticides against gypsy moth. In 1999, a new natural enemy, the entomopathogenic fungus Entomophaga maimaiga, was successfully introduced into a gypsy moth population in Bulgaria. Recent investigations suggest that now E. maimaiga is quickly spreading in Europe. Herein, past studies are reviewed regarding this fungus with special emphasis on its potential for becoming an important factor regulating gypsy moth populations in Europe, focusing on the host's population dynamics in relation to the fungus, the influence of environmental conditions on fungal activity, the influence of E. maimaiga on the native entomofauna, including other gypsy moth natural enemies, and spread of the fungus. Based on this analysis, the potential of E. maimaiga for providing control in European gypsy moth populations is estimated.     

Defoliation of wild native box trees (Buxus sempervirens): Does box rust (Puccinia buxi) infection influence herbivory,survival and growth of the invasive Cydalima perspectalis?

The invasive box‐tree moth Cydalima perspectalis causes damage to horticultural box trees (Buxus spp.) in private gardens and parks in Europe and defoliation of large areas of European native box trees Buxus sempervirens, which grow in the understorey of deciduous forests. In some parts of their distribution area, wild native box trees are infected by the box rust Puccinia buxi, a fungus which does not occur in the native range of C. perspectalis. We examined whether the infection of P. buxi deters grazing by C. perspectalis in 31 wild box‐tree stands in forests in north‐western Switzerland and south‐western Germany. On average, 82.4% of the box trees were infested by P. buxi (among‐site variation 20%–100%), or 18.5% of their leaves. Linear mixed‐effect (LME) models revealed that the percentage of rust‐infected leaves was influenced by the local box‐tree density and the slope aspect of the forest site. 9.5% of the leaves showed grazing damage by C. perspectalis. LME showed that the percentage of leaves with grazing damage was affected by the elevation of the site and the percentage of rust‐infected leaves. The effect of box rust infection on food choice and larval performance (survival and growth rate) was examined in two experiments. In food‐choice tests, larvae of C. perspectalis did not show any preference for uninfected or rust‐infected box‐tree leaves and consumed similar amounts of leaf tissue of either type. However, when larvae were reared on leaves with three different degrees of P. buxi‐infection (and uninfected leaves as control), both survival and growth rate decreased with increasing degree of rust infection. This indicates that larval performance of C. perspectalis is reduced by the box rust. In the case of an outbreak of C. perspectalis, however, larvae may indiscriminately defoliate wild box trees.     

Cryptolaemus montrouzieri as a predator of the striped mealybug,Ferrisia virgata,reared on two hosts

The striped mealybug, Ferrisia virgata (Cockerell) (Hemiptera: Pseudococcidae), is a cosmopolitan pest of a variety of agricultural crops including cotton. To investigate the biological control potential of the predatory ladybird Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) against this pest, we evaluated its developmental and reproductive fitness when feeding on F. virgata reared on pumpkin fruits or on cotton leaves and compared this to a diet of Planococcus citri Risso (Hemiptera: Pseudococcidae) reared on pumpkin fruits. F. virgata and P. citri reared on pumpkins were equally suitable prey for the pre‐imaginal stages of C. montrouzieri. Duration of total immature development was 1 day longer in C. montrouzieri offered F. virgata reared on cotton as compared with F. virgata or P. citri reared on pumpkin, whereas no significant difference was observed in survival rates. Diet significantly influenced the reproductive fitness of C. montrouzieri. Females offered P. citri reared on pumpkin had significantly shorter pre‐oviposition periods and higher fecundity and fertility than those given F. virgata reared on pumpkin or cotton leaves. F. virgata grown on cotton leaves supported the reproduction of C. montrouzieri better than F. virgata reared on pumpkin. Our study established that C. montrouzieri can successfully complete its development and reproduction when fed exclusively on F. virgata and indicates its potential as a biological control agent of this emerging cotton pest.     

Predicting the phenology of codling moth,Cydia pomonella,for sustainable pest management in Swiss apple orchards

The effects of temperature on post‐diapause development, female lifespan, and reproduction of Cydia pomonella L. (Lepidoptera: Tortricidae) were studied under controlled conditions to determine the respective parameters for a temperature‐driven phenology model. Lower thermal thresholds of 10.0 and 9.7 °C and thermal constants of 417.2 and 427.7 degree days were established for post‐diapause development of females and males, respectively. Female lifespan was found to be 202.6 degree days on average, with a lower thermal threshold of 11.2 °C. Total fecundity was highest at 27.7 °C with an average of 241.9 eggs per female. Literature data were used to quantify the lower thermal thresholds and the thermal constants for eggs, larvae, and pupae. For validation, the model was run with weather data from 13 consecutive years and the output was compared with pheromone trap catches from 39 to 63 different orchards, depending on the year. The model proved to be a reliable and useful tool to forecast codling moth phenology under Swiss conditions not only for a whole growing season but also during several years with very variable weather conditions. Hence, it can be used to support apple growers in pest management decisions on the one hand and to predict changes in codling moth phenology with respect to climate change on the other.     

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.     

Predicting bird phenology from space: satellite‐derived vegetation green‐up signal uncovers spatial variation in phenological synchrony between birds and their environment

Population‐level studies of how tit species (Parus spp.) track the changing phenology of their caterpillar food source have provided a model system allowing inference into how populations can adjust to changing climates, but are often limited because they implicitly assume all individuals experience similar environments. Ecologists are increasingly using satellite‐derived data to quantify aspects of animals' environments, but so far studies examining phenology have generally done so at large spatial scales. Considering the scale at which individuals experience their environment is likely to be key if we are to understand the ecological and evolutionary processes acting on reproductive phenology within populations. Here, we use time series of satellite images, with a resolution of 240 m, to quantify spatial variation in vegetation green‐up for a 385‐ha mixed‐deciduous woodland. Using data spanning 13 years, we demonstrate that annual population‐level measures of the timing of peak abundance of winter moth larvae (Operophtera brumata) and the timing of egg laying in great tits (Parus major) and blue tits (Cyanistes caeruleus) is related to satellite‐derived spring vegetation phenology. We go on to show that timing of local vegetation green‐up significantly explained individual differences in tit reproductive phenology within the population, and that the degree of synchrony between bird and vegetation phenology showed marked spatial variation across the woodland. Areas of high oak tree (Quercus robur) and hazel (Corylus avellana) density showed the strongest match between remote‐sensed vegetation phenology and reproductive phenology in both species. Marked within‐population variation in the extent to which phenology of different trophic levels match suggests that more attention should be given to small‐scale processes when exploring the causes and consequences of phenological matching. We discuss how use of remotely sensed data to study within‐population variation could broaden the scale and scope of studies exploring phenological synchrony between organisms and their environment.     

Inferring climatic controls of rice stem borers’ spatial distributions using maximum entropy modelling

Accurate assessment of pest potential distributions is needed to identify their establishment risks that play a key role in pest management in agricultural ecosystems. We used a correlative niche modelling method (Maxent) to predict and map the spatial distributions of two important rice stem borers, Chilo suppressalis and Sesamia cretica, in paddy fields of Iran. In total, 195 presence occurrence records (101 records for C. suppressalis and 94 records for S. cretica) were compiled. A set of environmental and topographic variables, with the highest effects on the species distributions and the lowest correlations among themselves, were used. The results showed that mainly the northern parts of Iran were the most suitable areas for C. suppressalis, and north, north‐east and south‐west of Iran as the most suitable areas for S. cretica. Both models performed well, with an area under the receiver operating characteristic curve (AUC) of 0.983 and 0.786 for C. suppressalis and S. cretica, respectively. The Maxent models showed higher accuracy for predicting the distribution of the specialist pest with the small range sizes compared to the generalist species. Assessing the importance of environmental variables, which were derived from the jackknife test, showed the precipitation as the variable with the highest contribution (66%) in explaining the spatial distribution of C. suppressalis compared to the other variables. The distribution of S. cretica was influenced by a set of variables derived from both the precipitation and temperature. The Maxent predictions were useful to map the geographical distributions of the risk for both rice stem borers that is needed to develop effective management strategies.     

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.     

New records of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) predation by Brazilian Hemipteran predatory bugs

The tomato borer Tuta absoluta, native to western South America, is an extremely devastating pest in tomato crops in most of South America, Europe and Africa North of the Sahel, causes yield losses up to 100% and decreases fruit quality in open field and greenhouse crops if control methods are not applied. In Brazil two other important lepidopteran pests – Neoleucinodes elegantalis and Helicoverpa zea – occur in tomato, as well as thrips, whiteflies and aphids. For control of these pests, frequent applications of pesticides of up to 5 times per week are needed, and these resulted in the appearance of resistant populations to a number of active ingredients and decimation of natural enemies. Biological control may offer a better, safer and more sustainable opportunity for pest management. Mirid predatory bugs are currently used with success in southern Europe to control T. absoluta and other pests. In Brazil, four Hemipteran predatory bugs, not yet known to attack T. absoluta, were found to successfully prey on eggs and larvae of this pest. The first results on their predation capacity, development, survival and reproduction on T. absoluta on tomato plants are presented.     

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.     

Adjusting the scent ratio: using genetically modified Vitis vinifera plants to manipulate European grapevine moth behaviour

Herbivorous insects use olfactory cues to locate their host plant within a complex olfactory landscape. One such example is the European grapevine moth Lobesia botrana, a key pest of the grape in the Palearctic region, which recently expanded both its geographical and host plant range. Previous studies have showed that a synthetic blend of the three terpenoids, (E)‐β‐caryophyllene, (E)‐β‐farnesene and (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT), was as attractive for the moth as the complete grape odour profile in laboratory conditions. The same studies also showed that the specific ratio of these compounds in the grape bouquet was crucial because a percentage variation in any of the three volatiles resulted in almost complete inhibition of the blend's attractiveness. Here, we report on the creation of stable grapevine transgenic lines, with modified (E)‐β‐caryophyllene and (E)‐β‐farnesene emission and thus with an altered ratio compared to the original plants. When headspace collections from these plants were tested in wind tunnel behavioural assays, they were less attractive than control extracts. This result was confirmed by testing synthetic blends imitating the ratio found on natural and transformed plants, as well as by testing the plants themselves. With this evidence, we suggest that a strategy based on volatile ratio modification may also interfere with the host‐finding behaviour of L. botrana in the field, creating avenues for new pest control methods.     

Invasion genetics of American cherry fruit fly in Europe and signals of hybridization with the European cherry fruit fly

The American cherry fruit fly is an invasive pest species in Europe, of serious concern in tart cherry production as well as for the potential to hybridize with the European cherry fruit fly, Rhagoletis cerasi L. (Diptera: Tephritidae), which might induce new pest dynamics. In the first European reports, the question arose whether only the eastern American cherry fruit fly, Rhagoletis cingulata (Loew) (Diptera: Tephritidae), is present, or also the closely related western American cherry fruit fly, Rhagoletis indifferens Curran. In this study, we investigate the species status of European populations by comparing these with populations of both American species from their native ranges, the invasion dynamics in German (first report in 1993) and Hungarian (first report in 2006) populations, and we test for signals of hybridization with the European cherry fruit fly. Although mtDNA sequence genealogy could not separate the two American species, cross‐species amplification of 14 microsatellite loci separated them with high probabilities (0.99–1.0) and provided evidence for R. cingulata in Europe. German and Hungarian R. cingulata populations differed significantly in microsatellite allele frequencies, mtDNA haplotype and wing pattern distributions, and both were genetically depauperate relative to North American populations. The diversity suggests independent founding events in Germany and Hungary. Within each country, R. cingulata displayed little or no structure in any trait, which agrees with rapid local range expansions. In cross‐species amplifications, signals of hybridization between R. cerasi and R. cingulata were found in 2% of R. cingulata individuals and in 3% of R. cerasi. All putative hybrids had R. cerasi mtDNA indicating that the original between‐species mating involved R. cerasi females and R. cingulata males.     

Diapause and biological cycle of Cydalima perspectalis (Walker) in the eastern Pyrenees

Boxwood is a very important component of the natural forests of the eastern Pyrenees. In the low altitudes of these forests, the invasive species Cydalima perspectalis (Walker) causes considerable damage, and there is concern that it will migrate towards the natural forests at higher altitudes. To determine the biological parameters of the local pest population, a semiartificial diet with lyophilized powdered Buxus sempervirens L. leaves was developed. The results obtained indicate that the studied population of C. perspectalis is very similar to the native Japanese population in terms of the number of larval instars to complete development, the development rate and the critical photoperiod for the induction of diapause. It has also been demonstrated that long photoperiods can shorten the duration of larval development. The diapause induction response was classified as type I, and diapause termination was classified as type III. At the two studied temperatures, 25º and 15ºC, the larvae seemed to require a similar number of days in diapause, approximately 3 months, to spontaneously resume development; temperatures can also prompt larvae to resume development. The critical photoperiod in the study area occurs during the second half of August, varying somewhat according to temperature. The greatest defoliation is caused by the offspring of the first generation, while the majority of the larval offspring of the second generation will enter diapause. The survival of natural boxwood in this area will depend on its ability to regrow one or two years after extensive defoliation and on the adaptation of several indigenous natural enemies in the region to feed on C. perspectalis.     

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.