Evolutionary genomics of three agricultural pest moths reveals rapid evolution of host adaptation and immune-related genes.

BACKGROUND: Understanding the genotype of pest species provides an important baseline for designing integrated pest management (IPM) strategies. Recently developed long-read sequence technologies make it possible to compare genomic features of nonmodel pest species to disclose the evolutionary path underlying the pest species profiles. Here we sequenced and assembled genomes for 3 agricultural pest gelechiid moths: Phthorimaea absoluta (tomato leafminer), Keiferia lycopersicella (tomato pinworm), and Scrobipalpa atriplicella (goosefoot groundling moth). We also compared genomes of tomato leafminer and tomato pinworm with published genomes of Phthorimaea operculella and Pectinophora gossypiella to investigate the gene family evolution related to the pest species profiles. RESULTS: We found that the 3 solanaceous feeding species, P. absoluta, K. lycopersicella, and P. operculella, are clustered together. Gene family evolution analyses with the 4 species show clear gene family expansions on host plant-associated genes for the 3 solanaceous feeding species. These genes are involved in host compound sensing (e.g., gustatory receptors), detoxification (e.g., ABC transporter C family, cytochrome P450, glucose-methanol-choline oxidoreductase, insect cuticle proteins, and UDP-glucuronosyl), and digestion (e.g., serine proteases and peptidase family S1). A gene ontology enrichment analysis of rapid evolving genes also suggests enriched functions in host sensing and immunity. CONCLUSIONS: Our results of family evolution analyses indicate that host plant adaptation and pathogen defense could be important drivers in species diversification among gelechiid moths.

Interbiotype hybridization between biotypes A and B of Liriomyza chinensis (Diptera: Agromyzidae).

Liriomyza chinensis (Kato) is a formidable pest of Allium species, especially the Japanese bunching onion Allium fistulosum L. Recently, a novel biotype of L. chinensis (biotype B) has emerged, which causes more severe damage than the native biotype A. It has been reported that biotype B has frequently displaced biotype A in the Japanese bunching onion fields in Japan. As interbiotype hybridization is a possible factor that influences such displacement, interbiotype hybridization was conducted between L. chinensis biotypes A and B. Eggs were not laid under one-by-one crossing conditions; however, adult hybrid progeny of both sexes emerged from no-choice mating combinations-when multiple males and females were present. The fertility of F1 hybrid adults was also investigated, and backcrossed adults emerged from F1 females in both mating combinations. F1 males might have exhibited reproductive abnormalities because only a small number of backcross progeny emerged from the mating combinations using F1 males. Additionally, 3 representative endosymbionts (Wolbachia, Spiroplasma, and Cardinium) were investigated, and both biotypes were found to be infected by the same strain of Wolbachia. In addition, the courtship signals (tapping) of male adults differed between biotypes A and B as well as between F1 hybrids; the F1 males exhibited tapping behavior that was intermediate between biotypes A and B. Therefore, mating sounds serve as a form of premating reproductive isolation between biotypes A and B.

Review of the genus Liocrobyla (Lepidoptera, Gracillariidae, Ornixolinae) from Korea, with description of one newly-recorded species.

Background: Liocrobyla Meyrick, 1916 is a relatively small genus within the family Gracillariidae, consisting of nine species worldwide, including five species in Korea. New information: In this study, we recognise five species belonging to the genus Liocrobyla Meyrick, 1916 from Korea. Amongst them, one species, L.indigofera Liu, Wang & Wang, 2018, is reported for the first time in Korea. Figures of adults, male and female genitalia, along with a key to the species of Liocrobyla in Korea, are provided.

Better Together: Volatile-Mediated Intraguild Effects on the Preference of Tuta absoluta and Trialeurodes vaporariorum for Tomato Plants.

Plant-herbivore interactions have been extensively studied in tomato plants and their most common pests. Tomato plant chemical defenses, both constitutive and inducible, play a role in mediating these interactions. Damaged tomato plants alter their volatile profiles, affecting herbivore preferences between undamaged and damaged plants. However, previous studies on tomato volatiles and herbivore preferences have yielded conflicting results, both in the volatile chemistry itself as well as in the attraction/repellent herbivore response. This study revisits the volatile-mediated interactions between tomato plants and two of their main herbivores: the leafminer Tuta absoluta and the whitefly Trialeurodes vaporariorum. Tomato plant volatiles were analyzed before and after damage by each of these herbivores, and the preference for oviposition (T. absoluta) and settling (T. vaporariorum) on undamaged and damaged plants was assessed both after conspecific and heterospecific damage. We found that both insects consistently preferred damaged plants over undamaged plants. The emission of herbivore-induced plant volatiles (HIPVs) increased after T. absoluta damage but decreased after T. vaporariorum damage. While some of our findings are in line with previous reports, T. absoluta preferred to oviposit on plants damaged by conspecifics, which differs from earlier studies. A comparison of HIPVs emitted after damage by T. absoluta and T. vaporariorum revealed differences in up- or down-regulation, as well as significant variations in specific compounds (12 for T. absoluta and 26 for T. vaporariorum damaged-plants). Only two compounds, ß-caryophyllene and tetradecane, significantly varied because of damage by either herbivore, in line with the overall variation of the HIPV blend. Differences in HIPVs and herbivore preferences may be attributed to the distinct feeding habits of both herbivores, which activate different defensive pathways in plants. The plant's challenge in simultaneously activating both defensive pathways may explain the preference for heterospecific damaged plants found in this study, which are also in line with our own observations in greenhouses.

Probe-based quantitative PCR and RPA-Cas12a molecular diagnostics for detection of the tomato pest Phthorimaea absoluta (Lepidoptera: Gelechiidae).

The tomato pest Phthorimaea absoluta Meyrick is highly invasive but has not yet invaded North America. However, several morphologically similar species are already present, making detection of P. absoluta presence and invasion challenging. We designed a quantitative PCR molecular diagnostic to differentiate P. absoluta, P. operculella (Zeller), or Keiferia lycopersicella (Walsingham) (Lepidoptera: Gelechiidae) DNA. Additionally, we developed an RPA-Cas12a molecular diagnostic that allows for the isothermal detection of P. absoluta DNA, eliminating the need for a thermocycler. The results of the RPA-Cas12a diagnostic can be visualized simply using a UV light source and cell phone camera. We expect these diagnostics to improve quarantine and prevention measures against this serious agricultural threat.

The phylogeny and divergence times of leaf-mining flies (Diptera: Agromyzidae) from anchored phylogenomics.

Leaf-mining flies (Diptera: Agromyzidae) are a diverse clade of phytophagous Diptera known largely for their economic impact as leaf- or stem-miners on vegetable and ornamental plants. Higher-level phylogenetic relationships of Agromyzidae have remained uncertain because of challenges in sampling of both taxa and characters for morphology and PCR-based Sanger-era molecular systematics. Here, we used hundreds of orthologous single-copy nuclear loci obtained from anchored hybrid enrichment (AHE) to reconstruct phylogenetic relationships among the major lineages of leaf-mining flies. The resulting phylogenetic trees are highly congruent and well-supported, except for a few deep nodes, when using different molecular data types and phylogenetic methods. Based on divergence time dating using a relaxed clock model-based analysis, leaf-mining flies are shown to have diversified in multiple lineages since the early Paleocene, approximately 65 million years ago. Our study not only reveals a revised classification system of leaf-mining flies, but also provides a new phylogenetic framework to understand their macroevolution.

Few indirect effects of baculovirus on parasitoids demonstrate high compatibility of biocontrol methods against Tuta absoluta.

BACKGROUND: Combining different biocontrol agents, particularly micro- and macroorganisms, can contribute to new and sustainable pest control approaches. Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most destructive pests of solanaceous crops. An emerging management strategy consists of biological control using microbial insecticides such as baculoviruses, but with limited efficacy. Thanks to their high target specificity, baculoviruses can be used simultaneously with natural enemies such as parasitoids for improved control of T. absoluta. However, potential indirect nontarget effects of baculoviruses on parasitoids can result from overlapping resource requirements. We assessed whether ovipositing parasitoid females discriminated against virus-treated hosts and examined the outcome of within-host competition between the hymenopteran parasitoids Necremnus tutae (Reuter) (Eulophidae) and Dolichogenidea gelechiidivoris Marsch (Braconidae), and the Phthorimaea operculella granulovirus (PhopGV, Baculoviridae) that infects T. absoluta larvae. RESULTS: Female D. gelechiidivoris discriminated against virus-treated hosts, whereas N. tutae did not. We found few indirect virus-related effects depending on the species, the sex, and the time of virus treatment. Effects were ambivalent for D. gelechiidivoris offspring and ranged from increased male longevity when infection occurred before parasitization to reduced emergence and male longevity when infection occurred after parasitization. N. tutae offspring showed a longer development time and shorter male longevity when they developed in virus-treated hosts. CONCLUSION: The virus had a low impact on parasitoid offspring. In rare cases, adverse effects were detected; however, the low magnitude of these effects is unlikely to reduce the fitness of parasitoid offspring, therefore both parasitoids seem compatible with the baculovirus for control of T. absoluta. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Asymmetric synthesis of the sex pheromone of the apple leafminer, Lyonetia prunifoliella.

Lyonetia prunifoliella is a significant pest in orchards and damages apple. The sex pheromones of this pest were prepared via a new and concise method. The central to our method were Evans' chiral auxiliaries, the addition of chiral Grignard reagent to aldehyde and Wittig coupling.

Demographics and host-kill parameters of Diglyphus horticola Khan against Chromatomyia horticola (Goureau).

The pea leafminer, Chromatomyia horticola (Goureau) (Diptera: Agromyzidae) is a polyphagous and serious pest of peas. In India, this pest is attacked by many parasitoids and among them Diglyphus horticola Khan (Hymenoptera: Eulophidae) is an important one, however, demographics and pest-kill potential of this parasitoid has not been studied so far. This study presents the first report on its demographics and pest-kill potential on C. horticola. The parasitoid showed three modes of host-killing behaviour viz. host-feeding, parasitism and host-stinging. The parasitoid females killed more number of hosts by parasitism than host-feeding or host-stinging. The pre-adult survival, net reproductive rate, intrinsic rate of increase (rm) and finite rate of increase (λ) were higher on the 5-days old host larvae than those reared on the 3-days old larvae. Demographics and pest-kill parameters of D. horticola were also better on 5-days old host larvae than on 3-days old host larvae. Based on the study, D. horticola appeared to be a promising biocontrol agent for the suppression of C. horticola in peas and could be promoted through conservation biological control. Further studies are required to standardize the mass production protocol and release rates to use the parasitoid by augmentation.

Taxonomic Review of the Genus Caloptilia Hübner, 1825 (Lepidoptera: Gracillariidae) with Descriptions of Three New Species and Seven Newly Recorded Species from Korea.

In this study, 29 species of Caloptilia Hübner, 1825, belonging to the family Gracillariidae, were recognized in Korea. Among these, three species, i.e., C. purpureus sp. nov., C. koreana sp. nov., and C. xanthos sp. nov., are described as new to science. In addition, seven species of this genus are reported for the first time in Korea. All known species were enumerated, based on their available information. Adult specimens and genitalia of the new and newly recorded species were examined and described using all available information.

Instar Determination for the Tomato Leafminer Tuta absoluta (Lepidoptera: Gelechiidae) Using the Density-Based OPTICS Clustering Algorithm.

The tomato leafminer Tuta absoluta (Meyrick) is one of the most harmful pests of solanaceous crops. Its larval morphological characteristics are similar, making the distinguishing between different larval instars difficult. Accurate identification of T. absoluta instars is necessary either for population outbreak forecasting, or developing successful control programs. Although a clustering algorithm can be used to determine the number of larval instars, little is known regarding the use of density-based ordering points to identify the clustering structure (OPTICS) and determine the number of larvae. In this study, larval instars of 240 T. absoluta individuals were determined by the density-based OPTICS clustering method, based on mandible width, and head capsule width and length. To verify the feasibility of the OPTICS clustering method, we compared it with the density-based spatial clustering of applications with noise (DBSCAN) clustering algorithm, Gaussian mixture models, and k-means. Additionally, the instars determined by the clustering methods were verified using the Brooks-Dyar rule, Crosby rule, and linear regression model. The instars determined by the OPTICS clustering method were equal to those determined by the other types of clustering algorithms, and the instar results were consistent with the Brooks-Dyar rule, Crosby rule, frequency analysis, and logarithmic regression model. These results indicated that the OPTICS clustering method is robust for determining insect larva instar phase. Moreover, it was found that three morphological indices of T. absoluta can be used for determining instars of this pest in the field, which may provide important information for the management of T. absoluta populations.

Diagnosis of Alternaria disease and leafminer pest on tomato leaves using image processing techniques.

BACKGROUND: Diseases such as Alternaria and pests such as leafminer threaten tomato as one of the most widely used agricultural products. These pests and diseases first damage the leaves of tomatoes, then the flowers, and finally the fruit. Therefore, the damage to the tomato tree must be controlled in its early stages. It is difficult for farmers to distinguish Alternaria disease from leafminer pest at the early and middle stages of their outbreak on tomato leaves. In the present study, 272 tomato leaf images were prepared from the farm of the Vali-e-Asr University of Rafsanjan, including 100 healthy leaves and 172 infected leaves with both Alternaria and leafminer at the initial stages. The image processing technique, texture, neural networks and adaptive network-based fuzzy inference system (ANFIS) classifiers were used to diagnose Alternaria disease and leafminer pest on this dataset. RESULTS: The results showed that the ANFIS classifier achieved an accuracy of 84.71% when performing an equal error rate, 87.78% in the area under the curve, and 85.23% in 3.26 s on the central processing unit for the segmentation of Alternaria disease and leafminer pest in RGB color space. Also, the accuracy of 90% and 98% were obtained for segmentation and classification on the PlantVillage dataset in YCBCR color space. CONCLUSION: The present study suggests a high classification accuracy for an intelligent selection of pixel values to train the ANFIS classifier. This classifier has high accuracy and speed, low sensitivity to the light intensity of images, and practical application in diagnosing various diseases and pests on numerous datasets. © 2022 Society of Chemical Industry.

Transcriptomics and Metabolomics Analyses Reveal High Induction of the Phenolamide Pathway in Tomato Plants Attacked by the Leafminer Tuta absoluta.

Tomato plants are attacked by a variety of herbivore pests and among them, the leafminer Tuta absoluta, which is currently a major threat to global tomato production. Although the commercial tomato is susceptible to T. absoluta attacks, a better understanding of the defensive plant responses to this pest will help in defining plant resistance traits and broaden the range of agronomic levers that can be used for an effective integrated pest management strategy over the crop cycle. In this study, we developed an integrative approach combining untargeted metabolomic and transcriptomic analyses to characterize the local and systemic metabolic responses of young tomato plants to T. absoluta larvae herbivory. From metabolomic analyses, the tomato response appeared to be both local and systemic, with a local response in infested leaves being much more intense than in other parts of the plant. The main response was a massive accumulation of phenolamides with great structural diversity, including rare derivatives composed of spermine and dihydrocinnamic acids. The accumulation of this family of specialized metabolites was supported by transcriptomic data, which showed induction of both phenylpropanoid and polyamine precursor pathways. Moreover, our transcriptomic data identified two genes strongly induced by T. absoluta herbivory, that we functionally characterized as putrescine hydroxycinnamoyl transferases. They catalyze the biosynthesis of several phenolamides, among which is caffeoylputrescine. Overall, this study provided new mechanistic clues of the tomato/T. absoluta interaction.

A DNA Extraction Method for Insects From Sticky Traps: Targeting a Low Abundance Pest, Phthorimaea absoluta (Lepidoptera: Gelechiidae), in Mixed Species Communities.

Invasive insects can cause catastrophic damage to ecosystems and cost billions of dollars each year due to management expenses and lost revenue. Rapid detection is an important step to prevent invasive insects from spreading, but improvements in detection capabilities are needed for bulk collections like those from sticky traps. Here we present a bulk DNA extraction method designed for the detection of Phthorimaea absoluta Meyrick (Lepidoptera: Gelechiidae), an invasive moth that can decimate tomato crops. We test the extraction method for insect specimens on sticky traps, subjected to different temperature and humidity conditions, and among mock insect communities left in the field for up to 21 d. We find that the extraction method yielded high success (>92%) in recovering target DNA across field and lab trials, without a decline in recovery after three weeks, across all treatments. These results may have a large impact on tomato growing regions where P. absoluta is in the early stages of invasion or not yet present. The extraction method can also be used to improve detection capabilities for other bulk insect collections, especially those using sticky traps, to the benefit of pest surveys and biodiversity studies.

Leafminer attack accelerates the development of soil-dwelling conspecific pupae via plant-mediated changes in belowground volatiles.

Herbivore population dynamics are strongly influenced by the interactions established through their shared host. Such plant-mediated interactions can occur between different herbivore species and different life developmental stages of the same herbivore. However, whether these interactions occur between leaf-feeding herbivores and their soil-dwelling pupae is unknown. We studied whether tomato (Solanum lycopersicum) leaf herbivory by the American serpentine leafminer Liriomyza trifolii affects the performance of conspecific pupae exposed to the soil headspace of the plant. To gain mechanistic insights, we performed insect bioassays with the jasmonate-deficient tomato mutant def-1 and its wild-type, along with phytohormones, gene expression and root volatiles analyses. Belowground volatiles accelerated leafminer metamorphosis when wild-type plants were attacked aboveground by conspecifics. The opposite pattern was observed for def-1 plants, in which aboveground herbivory slowed metamorphosis. Leafminer attack induced jasmonate and abscisic acid accumulation and modulated volatile production in tomato roots in a def-1-dependent manner. Our results demonstrate that aboveground herbivory triggers changes in root defence signalling and expression, which can directly or indirectly via changes in soil or microbial volatiles, alter pupal development time. This finding expands the repertoire of plant-herbivore interactions to herbivory-induced modulation of metamorphosis, with potential consequences for plant and herbivore community dynamics.

Comparing, evaluating and combining statistical species distribution models and CLIMEX to forecast the distributions of emerging crop pests.

BACKGROUND: Forecasting the spread of emerging pests is widely requested by pest management agencies in order to prioritise and target efforts. Two widely used approaches are statistical Species Distribution Models (SDMs) and CLIMEX, which uses ecophysiological parameters. Each have strengths and weaknesses. SDMs can incorporate almost any environmental condition and their accuracy can be formally evaluated to inform managers. However, accuracy is affected by data availability and can be limited for emerging pests, and SDMs usually predict year-round distributions, not seasonal outbreaks. CLIMEX can formally incorporate expert ecophysiological knowledge and predicts seasonal outbreaks. However, the methods for formal evaluation are limited and rarely applied. We argue that both approaches can be informative and complementary, but we need tools to integrate and evaluate their accuracy. Here we develop such an approach, and test it by forecasting the potential global range of the tomato pest Tuta absoluta. RESULTS: The accuracy of previously developed CLIMEX and new statistical SDMs were comparable on average, but the best statistical SDM techniques and environmental data substantially outperformed CLIMEX. The ensembled approach changes expectations of T. absoluta's spread. The pest's environmental tolerances and potential range in Africa, the Arabian Peninsula, Central Asia and Australia will be larger than previous estimates. CONCLUSION: We recommend that CLIMEX be considered one of a suite of SDM techniques and thus evaluated formally. CLIMEX and statistical SDMs should be compared and ensembled if possible. We provide code that can be used to do so when employing the biomod suite of SDM techniques. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A checklist of gymnosperm-feeding leafminers (Arthopoda, Insecta) in North America and Europe.

The leafminers on gymnosperms receive much less attention than those on either angiosperms or ferns. Given the distinctly different leaf shape and leaf venation found in gymnosperms, they would be expected to host significantly different leafminer groups. Very few comprehensive reports on gymnosperm-feeding leafminers have been presented. Based on the well-studied fauna in North America and Europe, we compiled a list of 133 species, 30 genera and 13 families of gymnosperm-feeding leafminers. The gymnosperm-mining families (in descending order of leafminer number) included Tortricidae, Gelechiidae, Argyresthiidae, Yponomeutidae, Batrachedridae, Pyralidae, Adelidae, Agromyzidae, Blastobasidae, Bucculatricidae, Coleophoridae, Curculionidae and Noctuidae. There were 109 species, 22 genera and ten families in North America and 34 species, 19 genera and nine families in Europe. We compiled a list of 102 species and 16 genera of host plants, belonging to four families: Pinaceae, Cupressaceae, Taxaceae and Zamiaceae. There were 84 host species, 15 genera and three host families in North America and 46 host species, ten genera and three host families in Europe. Dominant gymnosperm-mining families and dominant host families were generally the same in the two continents.

Screening Potential Reference Genes in Tuta absoluta with Real-Time Quantitative PCR Analysis under Different Experimental Conditions.

Tuta absoluta is one of the most significant invasive pests affecting tomato plants worldwide. RT-qPCR has emerged as one of the most sensitive and accurate methods for detecting gene expression data. The screening of stable internal reference genes is the most critical step for studying the molecular mechanisms of environmental adaptability. The stable reference genes expressed in T. absoluta under specific experimental conditions have not yet been clarified. In this study, seven candidate reference genes (RPL27, RPS13, RPS15, EF1-α, TUB, TBP, and ß-actin) and their optimal numbers were evaluated under biotic (developmental stages and adult tissues) and abiotic (insecticide, temperature, and plant VOC) conditions using four software programs. Our results identified the following reference genes and numbers as optimal: three genes (EF1-α, RPS13, and RPL27) for different developmental stages (egg, larva, pupa, unmated adult), two genes (RPS13 and TBP) for adult tissues (antenna, head, thorax, abdomen, leg), two genes (TBP and RPS13) for insecticides (Bacillus thuringiensis, chlorpyrifos, abamectin-aminomethyl, and chlorantraniliprole), two genes (RPL27 and TUB) for temperature-induced stresses (0, 25, and 40 °C), and two genes (RPS13 and TUB) for VOC-induced stresses (nonanal, α-phellandrene, and tomato leaves). Our results provide a reference for selecting appropriate reference genes for further study of the functional genes of T. absoluta under different experimental conditions.

Water Balance and Desiccation Tolerance of the Invasive South American Tomato Pinworm.

Temperature and dehydration stress are two major co-occurring environmental stressors threatening the physiology, biochemistry, and ecology of insects. As such, understanding adaptive responses to desiccation stress is critical for predicting climate change impacts, particularly its influence on insect invasions. Here, we assessed water balance and desiccation resistance of the invasive Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae), and infer how eco-physiology shapes its niche. We measured basal body water and lipid content, water loss rates (WLRs), and desiccation resistance in larvae (second to fourth instars) and adults. Body -water, -lipid, and WLRs significantly varied across life stages. Second instars recorded the lowest while fourth instars exhibited the highest body water and lipid content. Adult body water and lipid content were higher than second and third instars and lower than fourth instars while proportion of body water and lipid contents were highest in adults and second larval instars respectively. Water loss rates were significantly highest in fourth-instar larvae compared to other life stages, but differences among stages were less apparent at longer exposure durations (48 h). Desiccation resistance assays showed that second instars had greatest mortality while fourth-instar larvae and adults were the most desiccation tolerant. Our results show that T. absoluta fourth-instar larvae and adults are the most resilient developmental stages and potentially contribute most to the invasion success of the pest in arid environments. Incorporation of these species-specific eco-physiological traits in predictive models can help refine invasive species potential spread under changing climates.

Terpenes from herbivore-induced tomato plant volatiles attract Nesidiocoris tenuis (Hemiptera: Miridae), a predator of major tomato pests.

BACKGROUND: Biological control plays a key role in reducing crop damage by Tuta absoluta (Meyrick) and Trialeurodes vaporariorum (Westwood), which cause huge yield losses in tomato (Solanum lycopersicum L.). The mirid predator Nesidiocoris tenuis (Reuter) preys heavily on these pests, with satisfying control levels in tomato greenhouses. Although N. tenuis is known to be attracted to volatiles of tomato plants infested by T. absoluta and whitefly, little is known about the specific attractive compounds and the effect of prey density on the predator response. RESULTS: Y-tube olfactometer bioassays revealed that the attraction of N. tenuis to tomato volatiles was positively correlated with the density of T. absoluta infestation, unlike T. vaporariorum infestation. The predator was also attracted to volatiles of T. absoluta larval frass, but not to T. vaporariorum honeydew or T. absoluta sex pheromone. Among the herbivore-induced plant volatiles (HIPVs) that characterised the attractive plants infested with 20 T. absoluta larvae, olfactometer bioassays revealed that N. tenuis is attracted to the monoterpenes α-pinene, α-phellandrene, 3-carene, ß-phellandrene and ß-ocimene, whereas (E)-ß-caryophyllene was found to repel the predator. In dose-response bioassays, the five-component blend of the attractants elicited a relatively low attraction in the predator, and removal of ß-phellandrene from the blend enhanced the attraction of the predator to the resulting four-component blend, suggesting synergism among four monoterpenes. CONCLUSION: These findings suggest that a four-component blend of α-pinene, α-phellandrene, 3-carene and ß-ocimene could be used as a kairomone-based lure to recruit the predator for the biological control of T. absoluta and T. vaporariorum.