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Sex pheromones emitted by female moths play important roles in mate attraction. The molecular mechanism underlying pheromone biosynthesis activating neuropeptide (PBAN)‐regulated sex pheromone biosynthesis has been well elucidated in many moth species, although this mechanism is species‐dependent. Spodoptera litura, an important pest, has caused serious economic losses to agricultural production, yet the mechanism for its sex pheromone biosynthesis has not been fully identified. The present study investigates in detail mechanism underlying PBAN‐regulated sex pheromone biosynthesis in S. litura. The transcriptome sequencing of S. litura pheromone glands (PGs) was analysed to identify a serial of candidate genes potentially involved in sex pheromone biosynthesis. Further investigation revealed a bimodal pattern in both sex pheromone release and mating frequency. PBAN was found to regulate sex pheromone biosynthesis via its receptor by using Ca2+ as a secondary messenger, as demonstrated by RNA interference and the application of pharmacological inhibitors. Furthermore, PBAN/Ca2+ signalling activated calcineurin (CaN) and acetyl‐CoA carboxylase (ACC), which mediated sex pheromone biosynthesis in response to PBAN stimulation. Mostly importantly, hexokinase 2 (HK2) was confirmed to be activated by PBAN/PBANR /Ca2+/PKC signalling via phosphorylation at two specific sites (ser423 and ser434 sites of HK2). Overall, our findings shed light on the intricate processes involved in sex pheromone production in S. litura, in which PBAN regulates sex pheromone biosynthesis through PBAN/PBANR/Ca2+/CaN/ACC and PBAN/PBANR/Ca2+/PKC/HK2 signalling pathways. These insights significantly contribute to our comprehension of the specific mechanisms underlying sex pheromone biosynthesis in this moth species. [ABSTRACT FROM AUTHOR]

Sex pheromones, which consist of multiple components in specific ratios promote intraspecific sexual communications of insects. Plutella xylostella (L.) is a worldwide pest of cruciferous vegetables, the mating behavior of which is highly dependent on its olfactory system. Long trichoid sensilla on male antennae are the main olfactory sensilla that can sense sex pheromones. However, the underlying mechanisms remain unclear. In this study, 3 sex pheromone components from sex pheromone gland secretions of P. xylostella female adults were identified as Z11‐16:Ald, Z11‐16:Ac, and Z11‐16:OH in a ratio of 9.4 : 100 : 17 using gas chromatography – mass spectrometry and gas chromatography with electroantennographic detection. Electrophysiological responses of 581 and 385 long trichoid sensilla of male adults and female adults, respectively, to the 3 components were measured by single sensillum recording. Hierarchical clustering analysis showed that the long trichoid sensilla were of 6 different types. In the male antennae, 52.32%, 5.51%, and 1.89% of the sensilla responded to Z11‐16:Ald, Z11‐16:Ac, and Z11‐16:OH, which are named as A type, B type, and C type sensilla, respectively; 2.93% named as D type sensilla responded to both Z11‐16:Ald and Z11‐16:Ac, and 0.34% named as E type sensilla were sensitive to both Z11‐16:Ald and Z11‐16:OH. In the female antennae, only 7.53% of long trichoid sensilla responded to the sex pheromone components, A type sensilla were 3.64%, B type and C type sensilla were both 0.52%, D type sensilla were 1.30%, and 1.56% of the sensilla responded to all 3 components, which were named as F type sensilla. The responding long trichoid sensilla were located from the base to the terminal of the male antennae and from the base to the middle of the female antennae. The pheromone mixture (Z11‐16:Ald : Z11‐16:Ac : Z11‐16:OH = 9.4 : 100 : 17) had a weakly repellent effect on female adults of P. xylostella. Our results lay the foundation for further studies on sex pheromone communications in P. xylostella. [ABSTRACT FROM AUTHOR]

Simple Summary: The number of invasive pests has increased worldwide, mainly due to international trade. This problem is further exacerbated by climate change and the continued restrictions on the quantity and number of pesticides imposed by international authorities. Delottococcus aberiae, a mealybug native to South Africa, was first detected in Europe in 2009, specifically in the Valencia Community (Spain). The identification of its sex pheromone allowed the development of a monitoring network for this pest a decade later. This network facilitated the mapping of the affected citrus area and its subsequent expansion over time. The monitoring network has revealed that from 2019 until 2023, the citrus area affected by the pest has considerably increased. This network, in conjunction with fruit damage assessments conducted at the end of the crop cycle, has also allowed us to know that the damage to the fruit is independent of the maximum annual population level of the pest. The male catches obtained during the months of March to June, when fruit setting occurs, seem to be related to economic losses due to fruit damage. 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. [ABSTRACT FROM AUTHOR]

Simple Summary: The rice leaf-roller Cnaphalocrocis medinalis is a migratory pest of rice. Monitoring its population is important in integrated pest management systems. Trapping them with a sex pheromone or plant odor has been used in population monitoring. We studied the physiological status of adults trapped by sex pheromones and floral odors. In the immigrant group, the number of males caught in the floral trap was greater than those caught by the sex pheromone trap. The volumes of testes in adults caught using the above two trapping methods were similar. In the local breeding group, the number of males caught by sex pheromone trapping was greater than that by floral trapping. The volume of testes was smaller in males caught in the floral odor trap compared to the pheromone trap. In the emigrant group, the adult olfactory response to the sex pheromone and floral odor was low. The number of eggs laid by the females in the local breeding group was greater in those caught in the sweep net in comparison with those caught in the floral odor trap. 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. [ABSTRACT FROM AUTHOR]

Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) is a quarantine pest for certain export markets due to its phytosanitary status in affected crops in sub‐Saharan Africa, including citrus. Consequently, there is a zero‐tolerance policy for T. leucotreta in export markets. In South Africa, an integrated pest management strategy, incorporating a systems approach is used to achieve complete control of T. leucotreta. Preharvest management is multi‐faceted, including reliance on sex pheromone tools such as monitoring, attract‐and‐kill, mating disruptions, and sterile insect technique (SIT). Geographically isolated populations of T. leucotreta occur in South Africa, and there is speculation concerning the possible loss of sexual communication between these isolated populations, thereby compromising the efficiency of sex pheromone tools. To investigate this possibility, we collected samples from five geographically isolated populations of T. leucotreta and a population used for SIT in South Africa. These were subjected to sexual attraction trials under choice and no‐choice scenarios in a semi‐natural environment. Results of the choice tests revealed that males of each population preferred their corresponding population females, except irradiated males. However, when we deprived males of their preferred females, these preferences dissipated, and they were equally attracted to females from all populations. These results indicate that local adaptation and other selection forces in contrasting environments are important in sexual communication and selection in T. leucotreta but do not necessarily prevent recognition of sexual signals and attraction between geographically isolated populations. These findings are crucial for area‐wide IPM and precision control of T. leucotreta. [ABSTRACT FROM AUTHOR]

Juvenile diet can profoundly affect subsequent adult development, morphology and reproductive investment. Yet, little is known about how juvenile diet affects adult investment into chemical‐based sexual signalling, perhaps due to the historical assumption that pheromone production is not costly. We explored how juvenile diet influenced the reproductive investment of adults in the gumleaf skeletonizer moth, Uraba lugens. Juveniles were reared on different host plant species (Eucalyptus camaldulensis and Eucalyptus moorei) and on E. moorei host plants with different fertilizer treatments (fertilized and non‐fertilized). These juvenile diets differ in foliage carbon and nitrogen content. Several adult life history traits were influenced by juvenile diet, including body size in females, and longevity in males. However, we found no evidence from Y‐maze olfactometer assays that diet affected the attractiveness of female pheromones to males. Finally, host plant species affected male pre‐copulatory investment: males reared on E. moorei had longer antennae, but less dense sensilla. Combined, our experiments suggest that the effects of juvenile diet on investment in reproductive traits, including those associated with signalling, differ between males and females. Females allocate nutrients to adult body size, which determines fecundity. In contrast, males allocate nutrients to adult longevity and antennae size, both of which improve mate search and mating success. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Conogethes punctiferalis is a crop and fruit pest that has caused serious economic losses to agricultural production. This pest relies heavily on its sex pheromone to ensure sexual encounters and subsequent mating success. However, the molecular mechanism underlying sex pheromone biosynthesis in this species remains elusive. The present study investigated the detailed mechanism underlying PBAN-regulated sex pheromone biosynthesis in C. punctiferalis by transcriptome sequencing of the C. punctiferalis pheromone glands (PGs) and subsequent functional identification of the target genes. The results showed that female mating started from the first scotophase, and peaked at the second to fifth scotophases in accordance with the release of sex pheromones. PBAN regulated sex pheromone biosynthesis by employing Ca2+ and cAMP as secondary messengers, as demonstrated by RNA interference (RNAi), pharmacological inhibitors, and behavioral assays. Further investigation revealed that calcineurin (CaN) and acetyl-CoA carboxylase (ACC) were activated by PBAN/Ca2+ signaling, and the RNAi-mediated knockdown of CaN and ACC transcripts significantly reduced sex pheromone production, ultimately leading to a significantly reduced ability of females to attract males. Importantly, hexokinase (HK) was found to regulate sex pheromone biosynthesis in response to the PBAN/cAMP/PKA signaling pathway, as demonstrated by RNAi, enzyme activity, and pharmacological inhibitor assays. Furthermore, Far2 and Desaturase1 were found to participate in PBAN-regulated sex pheromone biosynthesis. Altogether, our findings revealed that PBAN regulates sex pheromone biosynthesis through the PBANR/Ca2+/CaN/ACC and PBANR/cAMP/PKA/HK pathways in C. punctiferalis, which enriches our comprehension of the details of sex pheromone biosynthesis in moths.

The tea tussock moth is a pest that damages tea leaves, affecting the quality and yield of tea and causing huge economic losses. The efficient asymmetric total synthesis of the sex pheromone of the tea tussock moth was achieved using commercially available starting materials with a 25% overall yield in 11 steps. Moreover, the chiral moiety was introduced by Evans' template and the key C-C bond construction was accomplished through Julia–Kocienski olefination coupling. The synthetic sex pheromone of the tea tussock moth will facilitate the subsequent assessment and implementation of pheromones as environmentally friendly tools for pest management. [ABSTRACT FROM AUTHOR]

Chemical, electrophysiological, and field trapping experiments were carried out to identify the female-produced sex pheromone of the asparagus moth, Parahypopta caestrum, a very serious pests of asparagus cultivations in southern Europe. Gas chromatography coupled with mass spectrometry and electroantennogram detection (GC-MS-EAD) analysis of hexane and solid-phase microextraction (SPME) extracts of sex pheromone glands of calling females consistently detected four compounds eliciting EAG responses in male moth antennae. According to their GC retention times, mass spectra, and comparative EAG analyses with reference standards, these EAD-active compounds were identified as (Z)-9-tetradecenol (Z9-14:OH), (Z)-5-tetradecenyl acetate (Z5-14:Ac), (Z)-7-tetradecenyl acetate (Z7-14:Ac), and (Z)-9-tetradecenyl acetate (Z9-14:Ac), respectively. In the SPME extracts from the head-space of individual abdominal tips, Z9-14:Ac, Z5-14:Ac, Z7-14:Ac, and Z9:14 OH were detected in the ratio of 82:9:5:4. In EAG dose-response experiments, Z9-14:Ac was the strongest antennal stimulant at different doses tested. In field trapping experiments, Z9-14:Ac, Z7-14:Ac, and Z5-14:Ac proven to be essential for male attraction and a their 85:5:10 blend loaded onto green rubber septum dispensers was significantly more effective than single-, two-, and any other three-component blend of these compounds. The addition of Z9-14:OH to the optimal blend resulted in a significant reduction of male catches. The attractive blend here identified allowed for an effective and accurate monitoring of P. caestrum flight activity in southern Italy. [ABSTRACT FROM AUTHOR]

Sex pheromones are considered to play critical roles in partner communication of most parasitic Hymenoptera. However, the identification of sex pheromone components remains limited to a few families of parasitoid wasps. In this study, we functionally characterized a candidate sex pheromone component in Microplitis mediator (Hymenoptera: Braconidae), a solitary parasitoid of Noctuidae insects. We found that the body surface extract from female wasps could significantly stimulate courtship behavior of males. Gas chromatography‐electroantennographic detection (GC‐EAD) analysis revealed that a candidate semiochemical from extract triggered significant electrophysiological response of antennae of males. By performing gas chromatography‐mass spectrometer (GC‐MS) measurement, GC‐EAD active compound was identified as n‐octyl acrylate, a candidate sex pheromone component in female M. mediator. In electroantennogram (EAG) tests, antennae of male wasps showed significantly higher electrophysiological responses to n‐octyl acrylate than those of females. Y‐tube olfactometer assays indicated that male wasps significantly chose n‐octyl acrylate compared with the control. Furthermore, male wasps showed a remarkable preference for n‐octyl acrylate in a simulated field condition behavioral trial; simultaneously, n‐octyl acrylate standard could also trigger significant courtship behavior in males. We propose that n‐octyl acrylate, as a candidate vital sex pheromone component, could be utilized to design behavioral regulators of M. mediator to implement the protection and utilization of natural enemies. [ABSTRACT FROM AUTHOR]

Sex pheromones play a crucial role in mate location and reproductive success. Insects face challenges in finding mates in low-density environments. The population dynamics of locusts vary greatly, ranging from solitary individuals to high-density swarms, leading to multiple-trait divergence between solitary and gregarious phases. However, differences in sexual communication between solitary and gregarious locusts have not been sufficiently explored. Herein, we found that solitary locusts but not gregarious ones heavily rely on a single compound, dibutyl phthalate (DBP), for sexual communication. DBP is abundantly released by solitary female locusts and elicits strong attraction of male solitary and gregarious locusts. Solitary adult males display much higher electrophysiological responses to DBP than adult females. Additionally, LmigOr13 was identified as the DBP-specific odorant receptor expressed in neurons housed in basiconic sensilla. Male LmigOr13-/- mutants generated by CRISPR/Cas9 have low electrophysiological responses and behavioral attraction to DBP in both laboratory and field cage experiments. Notably, the attractiveness of DBP to male locusts becomes more evident at lower population densities imposed by controlling the cage size. This finding sheds light on the utilization of a sex pheromone to promote reproductive success in extremely low-density conditions and provides important insights into alternative approaches for population monitoring of locusts. [ABSTRACT FROM AUTHOR]

Volatile sex pheromones are vital for sexual communication between males and females. Females of the American cockroach, Periplaneta americana, produce and emit two sex pheromone components, periplanone-A (PA) and periplanone-B (PB). Although PB is the major sex attractant and can attract males, how it interacts with PA in regulating sexual behaviors is still unknown. In this study, we found that in male cockroaches, PA counteracted PB attraction. We identified two odorant receptors (ORs), OR53 and OR100, as PB/PA and PA receptors, respectively. OR53 and OR100 were predominantly expressed in the antennae of sexually mature males, and their expression levels were regulated by the sex differentiation pathway and nutrition-responsive signals. Cellular localization of OR53 and OR100 in male antennae further revealed that two types of sensilla coordinate a complex two-pheromone-two-receptor pathway in regulating cockroach sexual behaviors. These findings indicate distinct functions of the two sex pheromone components, identify their receptors and possible regulatory mechanisms underlying the male-specific and age-dependent sexual behaviors, and can guide novel strategies for pest management. [ABSTRACT FROM AUTHOR]

The Lichen moth, Lyclene dharma dharma (Arctiidae, Lithosiinae), plays a significant role in forest ecosystem dynamics. A concise and novel method to synthesize the active sex pheromone components, (S)-14-methyloctadecan-2-one ((S)-1), (S)-6-methyloctadecan-2-one ((S)-2), and their enantiomers has been developed. Key steps in the synthesis include the use of Evans' chiral auxiliaries, Grignard cross-coupling reactions, hydroboration–oxidation, and Wacker oxidation. The synthesized sex pheromone components hold potential value for studies on communication mechanisms, species identification, and ecological management. [ABSTRACT FROM AUTHOR]

Simple Summary: Mass outbreaks of the pine sawfly Diprion pini can cause severe damage to pine forests. The larvae of this herbivorous insect feed selectively on the needles of pine trees, notably Pinus sylvestris. During mass outbreak periods, the females release large amounts of sex pheromones. A prior study revealed that the survival rate of sawfly eggs laid on pheromone-exposed pine needles was lower than that of eggs on unexposed pine. In our study, we found that D. pini females avoided oviposition on pheromone-exposed pine, possibly as a counter-adaptation to the enhanced defenses of previously pheromone-exposed trees against sawfly eggs. The females only discriminated between pheromone-exposed and unexposed trees when they had the chance to touch the needles, but not when exposed to the odor of these types of trees. However, the performance of larvae did not significantly differ on pheromone-exposed and unexposed trees. These results underscore the complexity of the chemical ecology of sawfly–pine interactions and highlight the nuanced roles that pheromones play in shaping the relationships between herbivores and their host plants. Insect pheromones have been intensively studied with respect to their role in insect communication. However, scarce knowledge is available on the impact of pheromones on plant responses, and how these in turn affect herbivorous insects. A previous study showed that exposure of pine (Pinus sylvestris) to the sex pheromones of the pine sawfly Diprion pini results in enhanced defenses against the eggs of this sawfly; the egg survival rate on pheromone-exposed pine needles was lower than that on unexposed pine. The long-lasting common evolutionary history of D. pini and P. sylvestris suggests that D. pini has developed counter-adaptations to these pine responses. Here, we investigated by behavioral assays how D. pini copes with the defenses of pheromone-exposed pine. The sawfly females did not discriminate between the odor of pheromone-exposed and unexposed pine. However, when they had the chance to contact the trees, more unexposed than pheromone-exposed trees received eggs. The exposure of pine to the pheromones did not affect the performance of larvae and their pupation success. Our findings indicate that the effects that responses of pine to D. pini sex pheromones exert on the sawfly eggs and sawfly oviposition behavior do not extend to effects on the larvae. [ABSTRACT FROM AUTHOR]

Sex pheromone analogs have high structural similarity to sex pheromone components. They also play a role in studying many agricultural pests. In our study, (Z , Z , Z)-3,6,9-nonadecadiene (Z 3 Z 6 Z 9-19:Hy) was successfully synthesized, which is an analogue to 1 of 2 sex pheromone components of Ectropis grisescens Warren (Z , Z , Z)-3,6,9-octadecatriene (Z 3 Z 6 Z 9-18:Hy), and it showed potential inhibition in experiments. In the electroantennogram test, Z3Z6Z9-19:Hy showed a dose-dependent response, and only measured half the response of Z 3 Z 9-6,7-epo-18:Hy. However, the compound significantly reduced positive response of E. grisescens males by up to 70% in the Y-tube olfactometer. Furthermore, in the wind tunnel, it significantly inhibited all types of behavioral responses. The percentage of moths contacting the pheromone odor source was reduced even at the lowest dose tested. In silico study afterward, molecular docking results showed affinity between Z 3 Z 6 Z 9-19:Hy and sensory neuron membrane protein 1. Our study revealed the potential of Z 3 Z 6 Z 9-19:Hy as a sex pheromone inhibitor, which would provide new tools for monitoring and mating disruption of E. grisescens. [ABSTRACT FROM AUTHOR]

Firefly flashes are well-known visual signals used by these insects to find, identify, and choose mates. However, many firefly species have lost the ability to produce light as adults. These "unlighted" species generally lack developed adult light organs, are diurnal rather than nocturnal, and are believed to use volatile pheromones acting over a distance to locate mates. While cuticular hydrocarbons, which may function in mate recognition at close range, have been examined for a handful of the over 2000 extant firefly species, no volatile pheromone has ever been identified. In this study, using coupled gas chromatography - electroantennographic detection, we detected a single female-emitted compound that elicited antennal responses from wild-caught male winter fireflies, Photinus corruscus. The compound was identified as (1S)-exo-3-hydroxycamphor (hydroxycamphor). In field trials at two sites across the species' eastern North American range, large numbers of male P. corruscus were attracted to synthesized hydroxycamphor, verifying its function as a volatile sex attractant pheromone. Males spent more time in contact with lures treated with synthesized hydroxycamphor than those treated with solvent only in laboratory two-choice assays. Further, using single sensillum recordings, we characterized a pheromone-sensitive odorant receptor neuron in a specific olfactory sensillum on male P. corruscus antennae and demonstrated its sensitivity to hydroxycamphor. Thus, this study has identified the first volatile pheromone and its corresponding sensory neuron for any firefly species, and provides a tool for monitoring P. corruscus populations for conservation and further inquiry into the chemical and cellular bases for sexual communication among fireflies.

Given the limited availability of resources in nature, sexual attractiveness may trade off with immunocompetence, as the immunocompetence handicap hypothesis (ICHH) posits. In invertebrates, a direct link between trade‐offs through hormonal/molecular effectors in sexual signals and immunity has not been found so far. Here, we assessed how variation in sexual signals affected parasite infection in two sex pheromone selected lines of the moth Chloridea virescens: an attractive line with a low ratio of 16:Ald/Z11‐16:Ald and an unattractive line with a high ratio. When infecting these lines with an apicomplexan parasite, we found that the attractive Low line was significantly more susceptible to the parasite infection than the unattractive High line. Since the ratio difference between these two lines is determined by a delta‐11‐desturase, we hypothesized that this desaturase may have a dual role, i.e., in the quality of the sexual signal as well as an involvement in immune response, comparable to testosterone in vertebrates. However, when we used CRISPR/cas9 to knockout delta‐11‐desturase in the attractive Low line, we found that the pheromonal phenotype did change to that of the High line, but the infection susceptibility did not. Notably, when checking the genomic location of delta‐11‐desaturase in the C. virescens, we found that mucin is adjacent to delta‐11‐desaturase. When comparing the mucin sequences in both lines, we found four nonsynonymous SNPs in the coding sequence, as well as intronic variation between the two lines. These differences suggest that genetic hitchhiking may explain the variation in susceptibility to parasitic infection. [ABSTRACT FROM AUTHOR]

A concise synthesis of the sex pheromones of elm spanworm as well as painted apple moth has been achieved. The key steps were the alkylation of acetylide ion, Sharpless asymmetric epoxidation and Brown's P2-Ni reduction. This approach provided the sex pheromone of the elm spanworm (1) in 31% total yield and those of the painted apple moth (2, 3) in 26% and 32% total yields. The ee values of three final products were up to 99%. The synthesized pheromones hold promising potential for use in the management and control of these pests. [ABSTRACT FROM AUTHOR]

The paulownia bagworm, Clania variegata Snell, is an economically important pest of agriculture and forests. The sex pheromone of this pest and its stereoisomers were synthesized, and two of the stereoisomers were prepared for the first time. Our strategy was efficient and mainly included the ring-opening reaction of (S)-2-methyloxirane, the coupling of chiral sulfonate, the oxidative cleavage of olefin, and Yamaguchi esterification. Moreover, the overall yields of our synthesis were 23–29%, with eight steps in the longest route. [ABSTRACT FROM AUTHOR]

Bactrocera tryoni (Froggatt) and Bactrocera neohumeralis (Hardy) are sibling fruit fly species that are sympatric over much of their ranges. Premating isolation of these close relatives is thought to be maintained in part by allochrony—mating activity in B. tryoni peaks at dusk, whereas in B. neohumeralis , it peaks earlier in the day. To ascertain whether differences in pheromone composition may also contribute to premating isolation between them, this study used solid-phase microextraction and gas chromatography-mass spectrometry to characterize the rectal gland volatiles of a recently collected and a more domesticated strain of each species. These glands are typical production sites and reservoirs of pheromones in bactrocerans. A total of 120 peaks were detected and 50 were identified. Differences were found in the composition of the rectal gland emissions between the sexes, species, and recently collected versus domesticated strains of each species. The compositional variation included several presence/absence and many quantitative differences. Species and strain differences in males included several relatively small alcohols, esters, and aliphatic amides. Species and strain differences in females also included some of the amides but additionally involved many fatty acid esters and 3 spiroacetals. While the strain differences indicate there is also heritable variation in rectal gland emissions within each species, the species differences imply that compositional differences in pheromones emitted from rectal glands could contribute to the premating isolation between B. tryoni and B. neohumeralis. The changes during domestication could also have significant implications for the efficacy of Sterile Insect Technique control programs. [ABSTRACT FROM AUTHOR]

In moths, pheromone receptors (PRs) are crucial for intraspecific sexual communication between males and females. Moth PRs are considered as an ideal model for studying the evolution of insect PRs, and a large number of PRs have been identified and functionally characterized in different moth species. Moth PRs were initially thought to fall into a single monophyletic clade in the odorant receptor (OR) family, but recent studies have shown that ORs in another lineage also bind type‐I sex pheromones, which indicates that type‐I PRs have multiple independent origins in the Lepidoptera. In this study, we investigated whether ORs of the pest moth Spodoptera frugiperda belonging to clades closely related to this novel PR lineage may also have the capacity to bind type‐I pheromones and serve as male PRs. Among the 7 ORs tested, only 1 (SfruOR23) exhibited a male‐biased expression pattern. Importantly, in vitro functional characterization showed that SfruOR23 could bind several type‐I sex pheromone compounds with Z‐9‐tetradecenal (Z9‐14:Ald), a minor component found in female sex pheromone glands, as the optimal ligand. In addition, SfruOR23 also showed weak responses to plant volatile organic compounds. Altogether, we characterized an S. frugiperda PR positioned in a lineage closely related to the novel PR clade, indicating that the type‐I PR lineage can be extended in moths. [ABSTRACT FROM AUTHOR]

Simple Summary: The tea geometrid (Ectropis obliqua (Prout)) is a major defoliator of tea plants and seriously affects the tea quality and yield in China. The females release three Type-II sex pheromone components for mate communication, but knowledge about the biosynthesis of these compounds is still limited. In this study, we screened for the candidate genes in the sex pheromone biosynthetic pathway with a combination of comparative RNAseq, phylogenetic relationship, and tissue expression pattern analyses. A total of seven tentative biosynthetic enzymes were identified, including two ELOs (ELO3 and ELO5), two FARs (FAR2 and FAR9), one DEC (CYP4G173), one LIP (LIP1), and one epoxidase (CYP340BD1). Overall, our results provide a foundation for further functional elucidation of the vital genes involved in E. obliqua sex pheromone biosynthesis. Ectropis obliqua, a notorious tea pest, produces a Type-II sex pheromone blend for mate communication. This blend contains (Z,Z,Z)-3,6,9-octadecatriene, (Z,Z)-3,9-cis-6,7-epoxy-octadecadiene, and (Z,Z)-3,9-cis-6,7-epoxy-nonadecadiene. To elucidate the genes related to the biosynthesis of these sex pheromone components, transcriptome sequencing of the female E. obliqua pheromone gland and the abdomen without pheromone gland was performed. Comparative RNAseq analyses identified 52 putative genes, including 7 fatty acyl-CoA elongases (ELOs), 9 fatty acyl-CoA reductases (FARs), 1 decarbonylase (DEC), 3 lipophorins (LIPs), and 32 cytochrome P450 enzymes (CYPs). Tissue expression profiles revealed that two ELOs (ELO3 and ELO5), two FARs (FAR2 and FAR9), one DEC (CYP4G173), and one LIP (LIP1) displayed either abdomen-centric or -specific expression, suggesting potential roles in sex pheromone biosynthesis within the oenocytes of E. obliqua. Furthermore, the tissue expression patterns, combined with phylogenetic analysis, showed that CYP340BD1, which was expressed specifically and predominantly only in the pheromone gland, was clustered with the previously reported epoxidases, highlighting its potential role in the epoxidation of the unsaturated polytriene sex pheromone components. Collectively, our research provides valuable insights into the genes linked to sex pheromone biosynthesis. [ABSTRACT FROM AUTHOR]

The peach fruit moth (Carposina sasakii Matsumura) is one of China's most serious fruitboring pests. Sex pheromone-based pest control has the advantages of being highly efficient, environmentally benign and rarely inducing pest resistance. However, the sex pheromone of the peach fruit moth, (Z)-12-decadecadecene-9-one and (Z)-13-decadecene-10-one, is extremely low in the pest. Therefore, it is insufficient for large-scale pest control via artificial extraction. An efficient synthesis of the sex pheromone has been developed via 7 steps including tetrahydro-2H-pyran-2-yl (THP) protection, nucleophilic substitution, Brown P2-Ni reduction, the addition of Grignard reagent and the oxidation with pyridinium dichromate (PDC) from 3-bromopropan-1-ol. Notably, Brown P2-Ni reduction was firstly used to construct a carbon-carbon double bond of the sex pheromone.The total yield was 5%. Our study has the advantages of simple operation and target pheromone with high regional selectivity (Z: E > 99:1), which could be used for the green control of the peach fruit moth. [ABSTRACT FROM AUTHOR]

BACKGROUND: Bactrocera minax is a devastating pest of citrus fruits. However, there have been no effective control measures before. Few reports on the sex pheromones of B. minax are available. RESULTS: In this study, nine of the volatile compounds in adult females were identified using headspace solid‐phase microextraction (HS‐SPME) in combination with gas chromatography–mass spectrometry (GC–MS). Among them, d‐limonene, caprolactam, 2‐Nitro‐1H‐imidazole, and creatinine could evoke antennal responses in males. Field bioassays showed that only d‐limonene could lure male flies, with a relative lure rate of 78.18% in all tested samples, which was significantly higher than that of paraffin oil control, while all volatile compounds did not have any lure effective to female flies. Moreover, d‐limonene was diluted with paraffin oil into differential concentrations, the lure effect on males was better at 100, 500, and 800 μL d‐limonene mL−1 than pure d‐limonene (1000 μL mL−1). The relative male lure rate of d‐limonene at 100 μL mL−1 was 85.88%, which was significantly higher than that of food−baits (14.12%) on day 3. However, d‐limonene was unattractive to female and male Bactrocera dorsalis and Zeugodacus tau. Further kinetic analysis showed that female adults released d‐limonene around 15‐day post eclosion. Electroantennography 1 results showed that 500 μL mL−1 d‐limonene evoked the strongest responses to antennae of 10‐ to 25‐day‐old male flies. CONCLUSION: Our results indicated that d‐limonene could be a sex pheromone from female flies of B. minax, and it could be used as a male‐specific sex attractant for B. minax. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Mate recognition is paramount for sexually reproducing animals, and many insects rely on cuticular hydrocarbons (CHCs) for close-range sexual communication. To ensure reliable mate recognition, intraspecific sex pheromone variability should be low. However, CHCs can be influenced by several factors, with the resulting variability potentially impacting sexual communication. While intraspecific CHC variability is a common phenomenon, the consequences thereof for mate recognition remain largely unknown. We investigated the effect of CHC variability on male responses in a parasitoid wasp showing a clear-cut within-population CHC polymorphism (three distinct female chemotypes, one thereof similar to male profiles). Males clearly discriminated between female and male CHCs, but not between female chemotypes in no-choice assays. When given a choice, a preference hierarchy emerged. Interestingly, the most attractive chemotype was the one most similar to male profiles. Mixtures of female CHCs were as attractive as chemotype-pure ones, while a female–male mixture negatively impacted male responses, indicating assessment of the entire, complex CHC profile composition. Our study reveals that the evaluation of CHC profiles can be strict towards 'undesirable' features, but simultaneously tolerant enough to cover a range of variants. This reconciles reliable mate recognition with naturally occurring variability. [ABSTRACT FROM AUTHOR]

Diabrotica balteata LeConte is one of the most important polyphagous agricultural pests. The sex pheromone of this pest was synthesized using Evans asymmetric alkylation, ring‐opening reaction of (R)‐2‐methyloxirane, SN2 alkylation of secondary tosylate, and coupling of chiral tosylate with Grignard reagent as central strategies. The sex pheromone prepared herein would be useful to control D. balteata. [ABSTRACT FROM AUTHOR]

Triatomines (Hemiptera: Heteroptera: Reduviidae), commonly known as conenose or kissing bugs, includes species of outstanding medical importance given their role as vectors of the protozoan parasite Trypanosoma cruzi Chagas (Kinetoplastida: Trypanosomatidae), the aetiological agent of Chagas disease. Herein, we present an updated review of the chemical ecology of triatomines, with special reference to molecules involved in the communication of these insects. Infochemicals, including hormones and semiochemicals (pheromones and allelochemicals), have a pivotal role in mediating information and shaping interactions within and between triatomines, during distinct behavioural contexts. We analyse the new findings about the chemical composition of alarm, aggregation and sex pheromones, as well as on cuticular hydrocarbons, host attractants and repellents. We also discuss how triatomine hormones may serve as communication signals and highlight the importance of the reverse chemical ecology approach in studying the complex chemoecology of these arthropod vectors. In the final section, we outline how knowledge about triatomine chemical ecology can be used for implementing real-world control operations with proven epidemiological impact. [ABSTRACT FROM AUTHOR]

As differences in sex pheromones usually act as a barrier against interspecific mating, the fact that the closely related moths Xylena fumosa (Butler) and X. formosa (Butler) (Lepidoptera: Noctuidae: Xyleninae) are commonly attracted to the sex pheromone lure for Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae: Heliothinae) seems unlikely, suggesting that some mechanisms exist between them to mitigate a potential reproductive interference in pheromone communications. Thus, we examined the overlaps in ecological niches of the two species, and their attractiveness to commercial pheromone lures for other moths, through pheromone trap surveys and published reports. Long‐term field surveys using traps baited with five to six types of artificial sex pheromone lures including those designed for H. armigera, and information in published works revealed that there was a nonnegligible overlap between the two species in terms of seasonal timing of captures, geographic habitats and host plants. These factors, therefore, did not appear to provide conclusive evidence mitigating reproductive interference. However, there was a slight but significant difference between them in the trends of attraction to different artificial pheromone lures; X. formosa was attracted albeit in a small number to the lures for Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae), whereas X. fumosa was only attracted to those for H. armigera. This suggests that differences in pheromone composition, rather than differences in temporal and spatial distributions, between the two species could play a more significant role in premating reproductive isolations. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Entomology is the property of Chinese Journal of Applied Entomology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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.

Pheromone receptors (PRs) are key proteins in the molecular mechanism of pheromone recognition, and exploring the functional differentiation of PRs between closely related species helps to understand the evolution of moth mating systems. Pheromone components of the agricultural pest Mythimna loreyi have turned into (Z)‐9‐tetradecen‐1‐yl acetate (Z9‐14:OAc), (Z)‐7‐dodecen‐1‐yl acetate (Z7‐12:OAc), and (Z)‐11‐hexadecen‐1‐yl acetate, while the composition differs from that of M. separata in the genus Mythimna. To understand the molecular mechanism of pheromone recognition, we sequenced and analyzed antennal transcriptomes to identify 62 odorant receptor (OR) genes. The expression levels of all putative ORs were analyzed using differentially expressed gene analysis. Six candidate PRs were quantified and functionally characterized in the Xenopus oocytes system. MlorPR6 and MlorPR3 were determined to be the receptors of major and minor components Z9‐14:OAc and Z7‐12:OAc. MlorPR1 and female antennae (FA)‐biased MlorPR5 both possessed the ability to detect pheromones of sympatric species, including (Z,E)‐9,12‐tetradecadien‐1‐ol, (Z)‐9‐tetradecen‐1‐ol, and (Z)‐9‐tetradecenal. Based on the comparison of PR functions between M. loreyi and M. separata, we analyzed the differentiation of pheromone recognition mechanisms during the evolution of the mating systems of 2 Mythimna species. [ABSTRACT FROM AUTHOR]

BACKGROUND: Mythimna loreyi is an important agricultural pest with a sensitive sex pheromone communication system. To clarify the pheromone binding proteins (PBPs) and pheromone receptors (PRs) involved in sex pheromone perception is important for both understanding the molecular olfactory mechanism and developing a new pest control strategy in M. loreyi. RESULTS: First, the electroantennogram (EAG) assay showed that male M. loreyi displayed the highest response to the major sex pheromone component Z9‐14:Ac, and higher responses to two minor components, Z7‐12:Ac and Z11‐16:Ac. Second, the fluorescence competition binding assay showed that PBP1 bound all three pheromones and other tested compounds with high or moderate affinity, while PBP2 and PBP3 each bound only one pheromone component and few other compounds. Third, functional study using the Xenopus oocyte system demonstrated that, of the six candidate PRs, PR2 was weakly sensitive to the major pheromone Z9‐14:Ac, but was strongly sensitive to pheromone analog Z9‐14:OH; PR3 was strongly and specifically sensitive to a minor component Z7‐12:Ac; PR4 and OR33 were both weakly sensitive to another minor component, Z11‐16:Ac. Finally, phylogenetic relationship and ligand profiles of PRs were compared among six species from two closely related genera Mythimna and Spodoptera, suggesting functional shifts of M. loreyi PRs toward Spodoptera PRs. CONCLUSION: Functional differentiations were revealed among three PBPs and six PRs in sex pheromone perception, laying an important basis for understanding the molecular mechanism of sex pheromone perception and for developing new control strategies in M. loreyi. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Sex pheromones have proven to be a viable tool for monitoring and controlling pests and is an important part of integrated pest management (IPM). The noctuid moth Macdunnoughia crassisigna Warren poses a significant threat as a defoliator pest, impacting soybean and cruciferous vegetable production and quality in East Asia. However, a lack of comprehensive knowledge about its sexual chemical signaling hampers the development of semiochemical‐based IPM approaches for M. crassisigna. RESULTS: We first determined the mating rhythms of M. crassisigna. We then collected pheromones from the sex glands of virgin females at the mating peak and analyzed their components using gas chromatography–electroantennogram detection analysis. The results showed that three components elicited significant electrophysiological responses in male antennae. Gas chromatography–mass spectrometry analysis characterized these components as (Z)‐7‐dodecene acetate (Z7‐12:OAc), (Z)‐9‐tetradecene acetate (Z9‐14:OAc), and (Z)‐11‐hexadecen‐1‐ol (Z11‐16:OH). Further field experiments indicated that the mixture of Z7‐12:OAc and Z9‐14:OAc at a ratio of 3:1 displayed significant attractivity to males, confirming its role as a putative sex pheromone of M. crassisigna. Long‐term monitoring tests showed that traps baited with these pheromone lures effectively mirrored the population dynamics of M. crassisigna. CONCLUSION: This study successfully identified and validated the sex pheromone released by female M. crassisigna and formulated potent sex lures for field‐based pest monitoring. These findings enriched our understanding of chemical communication in Noctuidae and laid a foundation for developing practical monitoring and control methods against M. crassisigna. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The mealybug, Planococcus ficus (Signoret), is a primary vineyard pest in California and other grape-growing regions throughout the World. Mating disruption programs are commercially available to manage Pl. ficus, but widespread adoption has been limited, in part, by high costs compared with insecticide programs. To improve mating disruption economic effectiveness, different deployment technologies (passive, aerosol, and microencapsulated formulations) were individually examined. Adult male Pl. ficus captures in pheromone traps and categorical ratings of vine infestation or crop damage suggest that all deployment strategies lowered mealybug densities or damage. Using passive dispensers, deployment rates of 310 and 465 per ha lowered Pl. ficus crop damage similar to 615 per ha, a rate commonly used in commercial operations; reduced rates would lower product and deployment costs. Meso dispensers, containing more a.i., deployed at 35 per ha did not have a treatment impact, but a microencapsulated formulation and aerosol canisters lowered male flight captures and/or crop damage. Male mealybug flight activity was greatest from 0500-1100 hr, which coincided with temperatures >16° and

Lyonetia clerkella Linnaeus is one of the notorious pests that are found in orchards. A new and efficient asymmetric synthesis of the sex pheromone of this pest has been developed. Central to this approach were 4-(dimethylamino)pyridine N-oxide (DMAPO)/Boc2O-mediated Nacylation, Evans'chiral auxiliaries and the coupling of chiral tosylate with n-propyl magnesium bromide. Furthermore, we have demonstrated the scalability of the new acylation. [ABSTRACT FROM AUTHOR]

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.

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.

The tea tussock moth is a pest that damages tea leaves, affecting the quality and yield of tea and causing huge economic losses. The efficient asymmetric total synthesis of the sex pheromone of the tea tussock moth was achieved using commercially available starting materials with a 25% overall yield in 11 steps. Moreover, the chiral moiety was introduced by Evans’ template and the key C-C bond construction was accomplished through Julia–Kocienski olefination coupling. The synthetic sex pheromone of the tea tussock moth will facilitate the subsequent assessment and implementation of pheromones as environmentally friendly tools for pest management.

Insect pheromones have been intensively studied with respect to their role in insect communication. However, scarce knowledge is available on the impact of pheromones on plant responses, and how these in turn affect herbivorous insects. A previous study showed that exposure of pine (Pinus sylvestris) to the sex pheromones of the pine sawfly Diprion pini results in enhanced defenses against the eggs of this sawfly; the egg survival rate on pheromone-exposed pine needles was lower than that on unexposed pine. The long-lasting common evolutionary history of D. pini and P. sylvestris suggests that D. pini has developed counter-adaptations to these pine responses. Here, we investigated by behavioral assays how D. pini copes with the defenses of pheromone-exposed pine. The sawfly females did not discriminate between the odor of pheromone-exposed and unexposed pine. However, when they had the chance to contact the trees, more unexposed than pheromone-exposed trees received eggs. The exposure of pine to the pheromones did not affect the performance of larvae and their pupation success. Our findings indicate that the effects that responses of pine to D. pini sex pheromones exert on the sawfly eggs and sawfly oviposition behavior do not extend to effects on the larvae.

The Lichen moth, Lyclene dharma dharma (Arctiidae, Lithosiinae), plays a significant role in forest ecosystem dynamics. A concise and novel method to synthesize the active sex pheromone components, (S)-14-methyloctadecan-2-one ((S)-1), (S)-6-methyloctadecan-2-one ((S)-2), and their enantiomers has been developed. Key steps in the synthesis include the use of Evans’ chiral auxiliaries, Grignard cross-coupling reactions, hydroboration–oxidation, and Wacker oxidation. The synthesized sex pheromone components hold potential value for studies on communication mechanisms, species identification, and ecological management.

The vine mealybug, Planococcus ficus, is a significant pest of vineyards in all major grape growing regions of the world. This pest causes significant aesthetic damage to berry clusters through its feeding behavior and secretion of ''honeydew'', which leads to significant decreases in crop marketability. More importantly, the vine mealybug is a vector of several grapevine viruses which are the causal agent of grapevine leafroll disease, one of the most destructive and economically devastating diseases of the grape industry worldwide. As there is no cure for grapevine leafroll disease, the only control measures available to reduce its spread are to remove infected vines whilst simultaneously controlling mealybug populations. Using transcriptomic libraries prepared from male and female mealybugs and a draft genome, we identified and evaluated expression levels of members of the odorant receptor gene family. Interestingly, of the 50 odorant receptors identified from these P. ficus genetic resources, only 23 were found to be expressed in females, suggesting this flightless life stage has a decreased reliance on the olfactory system. In contrast, 46 odorant receptors were found to be expressed in the alate male life stage. Heterologous expression of eight of these receptors, along with the obligate co-receptor, Orco, in HEK293 cells allowed for the identification of two receptors that respond to lavandulyl senecioate, the sole constituent of the sex pheromone used by this species. Interestingly, one of these receptors, PficOR8, also responded to the sex pheromone used by the Japanese mealybug, Planococcus kraunhiae. The data presented here represent the first report of odorant receptor gene family expression levels, as well as the identification of the first sex pheromone receptor, in soft-scale insects. The identification of a receptor for the vine mealybug sex pheromone will allow for the development of novel, species-specific pest control tools and monitoring devices.

Copyright of Journal of Guangxi Normal University - Natural Science Edition is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: General odor‐binding proteins (GOBPs) play critical roles in insect olfactory recognition of sex pheromones and plant volatiles. Therefore, the identification of GOBPs in Hyphantria cunea (Drury) based on their characterization to pheromone components and plant volatiles is remain unknown. RESULTS: In this study, two H. cunea (HcunGOBPs) genes were cloned, and their expression profiles and odorant binding characteristics were systematically analyzed. Firstly, the tissue expression study showed that both HcunGOBP1 and HcunGOBP2 were highly expressed in the antennae of both sexes, indicating their potential involvement in the perception of sex pheromones. Secondly, these two HcunGOBPs genes were expressed in Escherichia coli and ligand binding assays were used to assess the binding affinities to its sex pheromone components including two aldehydes and two epoxides, and some plant volatiles. HcunGOBP2 showed high binding affinities to two aldehyde components (Z9, Z12, Z15‐18Ald and Z9, Z12‐18Ald), and showed low binding affinities to two epoxide components (1, Z3, Z6‐9S, 10R‐epoxy‐21Hy and Z3, Z6‐9S, 10R‐epoxy‐21Hy), whereas HcunGOBP1 showed weak but significant binding to all four sex pheromone components. Furthermore, both HcunGOBPs demonstrated variable binding affinities to the plant volatiles tested. Thirdly, in silico studies of HcunGOBPs utilized homology, structure modeling, and molecular docking revealed critical hydrophobic residues might be involved in the binding of HcunGOBPs to their sex pheromone components and plant volatiles. CONCLUSION: Our study suggests that these two HcunGOBPs may serve as potential targets for future studies of HcunGOBPs ligand binding, providing insight in the mechanism of olfaction in H. cunea. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Identifying the sex pheromone systems of local pest populations facilitates their management, especially for moth species that show significant geographic variation in sex pheromone communication. We investigated the pheromone production and behavioral responses of the Asian corn borer (Ostrinia furnacalis Guenée; ACB) in Xinjiang, China. The ACB produces three compounds: (Z)-12-tetradecenyl acetate (Z12-14:Ac) and (E)-12-tetradecenyl acetate (E12-14:Ac) which are two sex pheromone compounds, and n-tetradecyl acetate (14:Ac) which has variable roles in mediating behavioral responses. The ratios of these three compounds produced in female gland are geographically distinct among different populations. Quantitative analysis of pheromone production showed that the proportions of Z12-14:Ac in the E/Z isomers (i.e., Z and E12-14:Ac) and the proportions of 14:Ac in the ternary blend respectively averaged 60.46% (SD=5.26) and 25.00% (SD=7.37), with their probabilities normally or near-normally distributed. Trapping experiments in a cornfield indicated that deploying the E/Z isomers and the three compounds in rubber septa close to their gland ratios yielded the most captured males, while other ratios that deviated from the gland ratios showed reduced field captures. The ternary blend was significantly more attractive to males than the E/Z isomers in the field, indicating a functional role of 14:Ac as the third pheromone component used by the local population. Additionally, the dose-response test demonstrated that the application of the three compounds at dosages between 200 and 350 μg attracted significantly more males compared to other dosages. Therefore, the characterization of this local ACB pheromone system provides additional information about its geographic variation and serves as a basis for optimizing the pheromone-mediated control of this pest in Xinjiang.

A concise synthesis of the sex pheromones of elm spanworm as well as painted apple moth has been achieved. The key steps were the alkylation of acetylide ion, Sharpless asymmetric epoxidation and Brown’s P2-Ni reduction. This approach provided the sex pheromone of the elm spanworm (1) in 31% total yield and those of the painted apple moth (2, 3) in 26% and 32% total yields. The ee values of three final products were up to 99%. The synthesized pheromones hold promising potential for use in the management and control of these pests.