Search Results (69)

Helopeltis cinchonae is an emerging pest of tea and causes severe damage to tea plantations in China. The female of H. cinchonae has been reported to produce a sex pheromone consisting of two components, hexyl (3R)-3-acetoxybutyrate and (5R)-1-acetoxy-5-butyroxyhexane, and lures containing the synthetic compounds have been shown to attract male H. cinchonae to traps in the field. This is the first time that components of the sex pheromone have been identified for a species of Helopeltis bug, but their field application has not been evaluated in detail. The present study shows that a blend of both compounds loaded into a polyethylene vial at 0.2 and 2 mg, respectively, caught significantly more male H. cinchonae bugs than the individual compounds and all the other tested blends. Sticky wing traps baited with the binary blend of compounds at the optimized ratio and dosage caught more bugs than bucket funnel or delta traps, and traps hung at a height of 10 cm above the tea shoots caught more bugs than those at other heights. The optimized traps and lures were used for monitoring the pest and two distinct population peaks of H. cinchonae were observed, the first one during mid-May to early June, and the other one in mid-September. Overall, the results of this study contribute to an environmentally-friendly approach to monitoring and managing H. cinchonae in the field. Full article

The fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) is an important invasive polyphagous crop pest that has been invading the world since 2016. This species consists of two strains adapted to different host plants, the corn strain and the rice strain, which also exhibit differences in their mating behavior, pheromone composition, and pheromone receptor sequences. A way to monitor invasion and control this pest is the use of synthetic sex pheromones to trap adults and disturb the mate-finding process via the release of large amounts of pheromones in the air. However, the efficiency of these methods depends on the specificity and sensitivity of the corresponding pheromone receptors. Yet, only pheromone receptors of the corn strain have been characterized, and nothing is known about the specificity and sensitivity of the rice strain orthologues. To address this gap, we functionally expressed the receptors to the major sex pheromone component of the two strains in Drosophila olfactory sensory neurons and challenged them with a large panel of pheromone compounds using single-sensillum recordings. Although their sequences present subtle mutations, we revealed that they share similar response spectra and sensitivity. The implications of these results on pheromone-based pest management strategies are discussed. Full article

Female mating success for the tortricids codling moth (CM), Cydia pomonella, Oriental fruit moth (OFM), Grapholita molesta, European grape vine moth (EGVM), Lobesia botrana, and five leafroller (LR) species under various mating disruption (MD) programs was reviewed at a time when new dual sex lures can provide alternative tools to assess female mating. Previous reliance on passive assessments such as tethering and virgin female-baited traps with laboratory moths are at odds with active trapping methods of wild moths. Additive factors such as delayed mating, adjustments in female behaviors, and greater levels of natural control may or may not contribute to the apparent success of MD. Current MD programs are not based solely on research, as economics and commercialization require some compromise. The complete sex pheromone blend is not always used. A delay in mating has been reported from the field with one study and suggested that reductions in fecundity would likely be minimal. There is no evidence that MD works better with low population densities. MD is an established technology, but the new dual sex lures are showing that the density of mated females is rather high. Efforts to improve the efficacy of MD are ongoing with a small cadre of researchers. Full article

A four-component blend comprising pear ester, DMNT, linalool oxide, and acetic acid (CM4K) was identified as a potent allelochemical lure for both sexes of codling moth (CM), Cydia pomonella (L.). Studies conducted from 2020 to 2022 in Washington State (USA) examined factors which could impact the lure’s relative performance. The CM4K lure was effective across a range of mating disruption programs and was equally attractive in monitoring wild and sterile CM. The lure remained attractive for at least 10 weeks. Total catch in traps baited with the CM4K was significantly less impacted than a sex pheromone lure located near mating disruption dispensers and female catches were largely unaffected. Traps with the CM4K lure caught significantly more females and fewer males when placed near clusters of fruits in a trellised orchard. Two factors were found to significantly impact the relative performance of the CM4K to sex pheromone lures: the CM4K lure was only equivalent to sex pheromone lures in pear MD orchards, and apple and pear orchards with vigorous weed growth. This is the first report of a monitoring lure for a tortricid moth being negatively impacted by the background odor of non-host weed species present within an orchard. Full article

Insects sense intraspecific or interspecific information about the chemical substances in the habitat through the sensitive olfactory system to carry out foraging, mating, oviposition, and other activities. The antennae serve as the primary olfactory organs in insects. The olfactory process involves the participation of many proteins, such as odorant-binding proteins (OBPs) and odorant receptors (ORs), but ORs play a central role in olfactory specificity and sensitivity. The beet webworm, Loxostege sticticalis, is an omnivorous agricultural pest that endangers crops and poses a significant risk to the agricultural and animal husbandry production in northern China. In this study, Illumina sequencing was conducted on the antennal transcriptome of male L. sticticalis trapped by three different sex pheromone blends. A total of 10,320 DEGs were identified, from which 46 candidate olfactory genes were selected for further analysis. These candidate olfactory genes comprise 13 odorant receptors, 6 ionotropic receptors (IRs), 3 gustatory receptors (GRs), 12 odorant-binding proteins, and 13 chemosensory proteins (CSPs). In summary, we analyzed the antennal transcriptome of male L. sticticalis trapped by three different sex pheromone blends and identified several candidate olfactory genes. This discovery offers a foundation for further molecular-level investigations into the olfactory system of L. sticticalis. Full article

The first occurrence of an invasive pest species, the fall armyworm (Spodoptera frugiperda, Lepidoptera: Noctuidae), in Bulgaria is reported. Different trapping methods (black light trap, traps baited with semiochemical lures, and food attractants) were used to study Noctuidae assemblages in Bulgaria in 2023. Two males of S. frugiperda were caught with sex pheromone traps in maize fields in Knezha, northern Bulgaria, in early November 2023. Additionally, three moths were attracted by black light traps (early November 2023) and one moth by a food lure applied on a tree trunk at the end of October 2023 in the municipalities of Parvomay and Chirpan, southern Bulgaria, respectively. The identification of S. frugiperda was confirmed using morphological and molecular methods. Full article

Tomato leaf miner Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has gained the status of major pest globally. Integrated pest management (IPM) consists of different control methods. This field study was conducted to evaluate the influence of different pheromone-based traps to attract the male population and the potential of sticky pads of four different colors in capturing the adults in the absence of pheromone lures. The trials were conducted in Khyber Pakhtunkhwa (Pakistan) for two consecutive years, 2020 and 2021. The Delta trap with rubber septum type lure was significantly more attractive in both years, with mean number of capturing 76.0 and 86.17, as compared to polymer wax (32.83 and 28.2) and polymer vial (10.37 and 11.77), lures. The highest mean number of capturing of T. absoluta adults were noted as 17.93 and 21.73 with black color sticky trap without pheromone, whereas the lowest number of adults, i.e., 1.33 and 1.47, were captured during the first and second year of the study, respectively, with yellow color sticky traps. However, a significant difference was found in pheromone lures and among black, red, green, and yellow color sticky pads. Hence, Delta traps equipped with rubber septum pheromones lures and black colored sticky pads were more useful for the control of T. absoluta than any other colored sticky pads and pheromone lures alone. These findings could be helpful for the integrated management of T. absoluta. Full article

Eogystia hippophaecolus (Hua, Chou, Fang et Chen) is a drilling pest that damages sea buckthorn, leading to substantial ecological and economic losses in areas where sea buckthorn is cultivated in China. Pheromone lures are widely used to monitor and trap male moths; however, the olfactory recognition mechanisms in male moths require further investigation. In this study, we characterized odorant receptor genes using phylogenetics, gene expression, sequence analyses and molecular docking. A phylogenetic analysis using the maximum likelihood method revealed that odorant receptor co-receptor (EhipOrco) genes clustered with other lepidopteran Orco genes, while pheromone receptor (EhipPR) genes clustered with other lepidopteran PR genes, suggesting that these genes have similar functions. The expression levels of 27 odorant receptor (EhipOR) genes in five tissues of male adults were analyzed using qPCR. Nine EhipOR genes were specifically expressed in the antennae, while several EhipOR genes were highly expressed in the head, feet, and external genitalia. As determined using molecular docking, EhipPR1–3 bound strongly to the primary sex pheromone components of E. hippophaecolus. Additionally, EhipPR1–3 demonstrated a strong binding affinity for longifolene among sea buckthorn volatiles. This study provides a foundation for future functional research on EhipORs and the olfactory recognition mechanisms of E. hippophaecolus. Full article

The emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an invasive forest pest that is causing a rapid decline in ash (Fraxinus spp.). As EABs spread across North America to 35 U.S. states and 5 Canadian provinces, detection of the pest has proven difficult, especially at low population density sites. Panel traps have been commonly used in detection and monitoring of EAB populations. Over two sampling periods from 2016 through 2019, adult catches and detection rates were compared among four combinations of panel trap color, lure, and crown placement in southern Arkansas, northern Louisiana, and eastern Texas. The four combinations were as follows: (1) dark purple baited with (Z)-3-hexenol alone in the mid–upper crown; (2) light green with (Z)-3-hexenol plus (3Z)-lactone in the mid–upper crown; (3) dark purple with (Z)-3-hexenol in the lower crown; and (4) dark purple with (Z)-3-hexenol plus (3Z)-lactone in the lower crown. Mid–upper tree crown placement, ~13 m, of panel traps were more effective for EAB detection and adult capture, especially of males. The sex pheromone (3Z)-lactone deterred females but attracted males, while (Z)-3-hexenol attracted females. The green panel trap with both lures and mid–upper crown placement did not drastically increase male catches, contrary to previous studies at low EAB densities. The use of (3Z)-lactone on dark purple traps at low crown placements, such as those used in the National Survey Program, is not recommended for EAB detection due to its repellent effect on EAB females. Full article

The plum fruit moth (PFM), Grapholita funebrana, and the oriental fruit moth (OFM), G. molesta, are closely related fruit moth species that severely damage fruit trees in Rosaceae. Both species share common primary sex pheromone components Z8-12:Ac and E8-12:Ac. The secondary sex pheromone components of PFMs consist of Z8-12:OH, Z8-14:Ac, and Z10-14:Ac, while those of OFMs include Z8-12:OH and 12:OH. Previous researchers have proved that the inclusion of Z8-14:Ac and Z10-14:Ac did not augment PFM catches but inhibited OFM catches in orchards in Europe, thereby maintaining the species-specificity of the PFM sex attractant. However, which of these components, Z8-14:Ac or Z10-14:Ac, plays the major role in inhibiting OFM attraction remains unclear. In the current study, electroantennogram (EAG) assays indicated that both OFM and PFM males exhibited a moderate EAG response to Z8-14:Ac and Z10-14:Ac. Rubber septa loaded with varying ratios of Z8-14:Ac (1% to 30%) or Z10-14:Ac (5% to 110%) combined with a constant dose of Z8-12:Ac and E8-12:Ac produced diverse trapping effects. Sex attractants containing Z8-14:Ac did not significantly affect the trapping of PFM males but drastically reduced the capture of OFM males, with the reduction reaching up to 96.54%. Attractants containing more than 10% of Z10-14:Ac simultaneously reduced the number of OFM and PFM males captured. Z8-14:Ac was indispensable for maintaining the specificity of sex pheromones. Fluorescence competitive binding assays of recombinant GmolPBP2 showed the lowest K_i value (0.66 ± 0.02 μM) among the PBPs/GOBPs from OFMs, suggesting that it is the most likely target for Z8-14:Ac. Molecular dynamic simulation and site-directed mutagenesis assays confirmed that the Phe12 residue, which forms a π–alkyl interaction with Z8-14:Ac, was crucial for GmolPBP2 binding to Z8-14:Ac. In conclusion, Z8-14:Ac is vital to the specificity of PFM sex pheromones inhibiting OFM attractants when added to Z8-12:Ac and E8-12:Ac. This could be potentially used to develop species-specific sex attractants for the PFM. Full article

During the spring–summer seasons between 2019 and 2023, in the localities of Maquehue (La Araucanía Region) and Llifén (Los Ríos Region), we collected 262 virgin Proholopterus chilensis (1 female/2.3 males) specimens emerging from the live trunks of N. obliqua trees, an atypical sex ratio in Cerambycidae, suggesting high male competition for females. Virgin specimens of both sexes were individually placed in panel traps in the field, capturing only males (n = 184) over the field study seasons and only in traps baited with females. This fact preliminarily suggests the P. chilensis females emit possible “volatile or airborne” pheromones (eventually being a long-range sex pheromone), something unusual in Cerambycinae, the subfamily to which it currently belongs, although the taxonomic status of the species is under debate. In Llifén and Santiago (Metropolitan Region), behavioral observations were conducted, which allowed us to define the conditions necessary for male–female encounters that were replicated when carrying out volatile captures (Head Space Dynamic = HSD) and collections of compounds from terminalias excised from females. In field trials, virgin females less than ten days old were more attractive than older ones and attracted males during the night, i.e., between 23:00 and 5:00 AM, when the ambient temperature exceeded 11.6 °C. The aeration of females under the conditions described above and subsequent analysis of extracts by GC-MS allowed the identification of compounds absent in males and the control, including two oxygenated sesquiterpenes, a nitrogenous compound (C₂₀), and a long-chain hydrocarbon (C₂₆). From the terminalia extracts, hentriacontane, heptacosane, and heneicosyl, heptacosyl and docosyl acetates were identified by GC-MS, and their roles are unknown in the development of short-distance sexual behaviors, but they could serve to mark a trail leading the male towards the female in the final stage of approach for courtship/mating. Thus, we proposed the hypothesis that P. chilensis females emit both a long-range and a trail-pheromone, which, if confirmed, would be a rare case in this family. The specific identity of the compounds obtained by HSD, as well as the activities of these chemicals and those obtained from the terminalias, should be evaluated in future behavioral studies, as well as regarding their potential to attract males under field conditions. The current document is the first report on volatiles obtained from aerations and compounds extracted from female terminalia in P. chilensis. Full article

The Indian meal moth, Plodia interpunctella, poses a significant threat to global agricultural products. Although pheromone-based technologies show promise for P. interpunctella management, limitations such as single-sex targeting necessitate exploring complementary strategies. Vegetable-based oils represent a potential alternative but their efficacy, sex-specificity, and interaction with sex pheromones remain unclear. To address these questions, we first examined the attraction of P. interpunctella female and male adults to 10 commercially available vegetable oils in semi-field conditions. Sesame, olive, and blended oils were the most attractive, capturing significantly more adults compared to other oils. We then evaluated the effectiveness of these three attractive oils and their combinations with P. interpunctella sex pheromones in a grain warehouse. Traps baited with these oils captured significantly more females and males compared to control traps without attractants; however, the addition of sex pheromones did not improve male capture and significantly reduced female capture, suggesting an inhibitory effect. Finally, we demonstrated that female mating status (mated vs. virgin) did not influence the attractiveness of traps baited with these effective oils. Our findings highlight the potential of standalone traps baited with blended, olive, or sesame oil as a practical, economic, and effective management strategy for P. interpunctella in storage facilities. Full article

The invasive mealybug Delottococcus aberiae De Lotto (Hemiptera: Pseudococcidae) has rapidly spread in the Mediterranean basin since its detection in 2009 in the Valencia Community in eastern Spain. The use of sticky traps baited with its sex pheromone, (4,5,5-trimethyl-3-methylenecyclopent-1-en-1-yl)methyl acetate, has allowed to determine the geographical distribution of D. aberiae by means of the surveillance network described in the present work. The population monitoring of the pest over a five-year period (2019–2023) has revealed an increase from 31% to 70% of the affected citrus-growing area. The monitoring network has also allowed a better understanding of the pests’ biological cycle throughout the year. The populations start growing from March to June and reach their maximum in July–August. During autumn, there is a gradual decline in the population. Although the highest annual populations were detected in 2022 and 2023, the greatest crop losses were recorded in 2020 and 2021, with mean values near 18%. Data suggest that the damage responsible for fruit deformation, and thus the economic losses, are related to the population levels in spring (April–May) rather than those in summer (July–August). The findings of this study can be valuable for future research and development of effective pest control strategies. Full article

The rice leaf-roller Cnaphalocrocis medinalis is an important migratory pest of rice. We conducted a study to determine the physiological status of adults trapped by a sex pheromone and floral odor. In the immigrant group, the number of males trapped by the floral odor was greater than the number caught by sex pheromone trapping. The volume of testes was similar in the above two trapping methods but was smaller than in the sweep net method. The ovary developmental grade, mating rate, and number of matings of females caught in floral odor trap were higher than in those caught in the sweep net. In the local breeding group, the number of males trapped by sex pheromones was greater than the number trapped by the floral odor. The volume of testes was smaller in the floral odor trap compared to the pheromone trap group, with the largest in the sweep net group. The ovarian developmental grade, mating rate, and number of matings of females were significantly higher in the floral odor trap group than in the sweep net group. In the emigrant group, the adult olfactory response to the sex pheromone and floral odor was low. The volume of testes was larger in the sweep net group compared to the moths caught by floral odor trapping. The number of eggs laid by female immigrants trapped by the floral odor and sweep net was similar, while the number in the local breeding group was greater in moths caught with the sweep net in comparison with those caught by the floral odor trap. The difference in egg hatchability between the two trapping methods in both immigrants and local breedings was not significant. Full article

Helicoverpa armigera (Hübner) is a destructive agricultural pest. Facultative migration usually causes regional catastrophes; therefore, developing a simple and easy new technology for the monitoring and early warning of immigrant populations is urgent. Between 2021 and 2023, we conducted a population-monitoring study on H. armigera immigrants in Xundian County, Yunnan Province, where the migration pathway for pests from southeast Asia extends to southwest China. Based on the differences in the reproductive organ development parameters of H. armigera at different ages, we established an adult age discrimination model. The monitoring results of field populations with semiochemical attractants and sex pheromones between 2021 and 2023 showed that the daily average age of the adult population of H. armigera fluctuated above 6 days, and the trapping dynamics with semiochemical attractants and sex pheromones were the same. Both trapping methods yielded H. armigera males of different ages and had identical age structures, indicating that the H. armigera population primarily migrated from other regions. The trajectory analysis showed that the H. armigera population that migrated to Xundian between May and September was primarily from South Kunming, and after October, it was primarily the southward-migrating population north of Qujing City, Yunnan Province. Based on the relationship between the daily average fecundity and the age of H. armigera, a dynamic prediction model for the fecundity of the immigrant population was established. In this study, the prediction models and methods based on semiochemical attractants could potentially be used in the surveillance and population alerting of H. armigera. Full article