Dual Choice Research Articles

Compatibility of Chrysoperla carnea (Neuroptera: Chrysopidae) with nanoformulations of natural active substances.

Nanoformulations of essential oils (EOs) improve stability of the active ingredient, and thereby its biological activity and persistence. Because compatibility of EOs with natural enemies is not explored sufficiently, we evaluated the impact of nanoformulations of EOs (aniseed, lemon) or pure products (farnesol) on different activities of the generalist predator Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae). In dual choice bioassay, chrysopid larvae were significantly attracted to aniseed-treated pepper disks and deterred by farnesol. Larval activities (resting, walking, and preying) on treated leaves infested with Myzus persicae (Sulzer) (Hemiptera: Aphididae) were compared. There were no differences among nanoemulsions, nor aphid consumption varied. We studied the toxicity of nanoformulations to larvae and evaluated their development after contact with treated leaf disks, ingestion of treated artificial diet, and both routes of exposure (application of biopesticides on aphid-infested plants). This is the first evidence of the compatibility of EO nanoformulations with C. carnea by single route of exposure. Whether any effect appeared, it was sublethal. Compounds significantly reduced aphid consumption after 6 h on double route exposure, but this negative short-term effect disappeared as time progressed. Our results showed the optimal biopesticide to apply depends on which biological feature of the natural enemy we targeted. The key element to introduce these nanoemulsions is to match their persistence period on the crop with the release of the appropriate biological stage of C. carnea. This reinforces the fact that the main activities of C. carnea can be substantially maintained in joint application with nanoemulsions of EOs.

A wireless, remotely operable and easily customizable robotic flower system

Abstract Understanding the complex interactions between external and internal factors that influence pollinator foraging behaviour is essential to understand ecosystem functioning, design agricultural practices or develop effective conservation strategies. However, it remains challenging to collect large and reliable data sets with reasonable personnel and workload. In this study, we present a wireless and cost‐effective robotic flower equipped with internet of things (IoT) technology that automatically offers nectar to visiting insects while monitoring visitation time and duration. The robotic flower is easy to manipulate and settings such as nectar refill rates can be remotely altered, making it ideal for field settings. The system transmits data completely wirelessly and autonomously, is mobile and easy to clean. The prototype settings allow for approximately 2 weeks of uninterrupted data collection for each battery charge. As a proof‐of‐concept application, a foraging preference dual choice experiment with bumblebees was performed. On average, more than 7000 flower visits per colony were registered daily with a set‐up consisting of 16 robotic flowers. The data show a gradual preference shift away from the pre‐trained low concentration, confirming the hypothesis of favouring sugar water with higher concentration. The robotic flower provides accurate and reliable data on insect behaviour, significantly reducing the price and/or labour costs. Although primarily designed for (bumble)bees, the system could be easily adapted for other flower‐visiting insects. The robotic flower is user‐friendly and can be easily adapted to address a wide range of research questions in pollination ecology, conservation biology, biocontrol and ecotoxicology, and allows for detailed studies on how nectar traits, flower colour and shape or pollutants affect foraging behaviour.

Assessment of the efficacy of Piper methysticum (Micrembryeae: Piperaceae) as a bioinsecticide, and/or spinosad combined with attractive plant volatiles for a novel lure and kill strategy against Bactrocera tryoni (Diptera: Tephritidae) in laboratory.

The Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), is a crop pest of global economic importance because of its wide range of hosts and its invasiveness capacities. To develop a novel integrated and sustainable crop protection, we have investigated the insecticidal properties of different varieties of kava (Piper methysticum [Frost]) extracted by two methods and the attractive effects of six plant volatiles identified from B. tryoni host plants to female, mated or not. We did not identify any significant insecticidal effect of the traditional Pacific kava plant at the tested concentrations. Among mated females, ethyl acetate compared to the no odor control elicited the highest attraction (87%, of which 60% for this odor), while ethyl butyrate was preferred compared with ethyl acetate in dual choice assays. Flies' preferences for specific odors depended on their mating status and the odor landscape they were confronted with. Combination with the commercial ingestion insecticide (Success 4: spinosad, 480 g/l, Dow AgroSciences, Valbonne, France) with the plant volatiles were tested to detect an increase in mortality related to the addition of an attractant. The 2-heptanone slightly showed a tend to increase the attractiveness of mated females within 4-6 h to the food bait, but the results were not statistically significant after 8 h. Further tests should be performed with other concentrations or mixtures of the identified host plant volatiles to develop a strong lure and kill strategy.

Experience of financial toxicity and coping strategies in young and middle-aged patients with stroke: a qualitative study

BackgroundWhile financial toxicity (FT) is prevalent in patients with cancer, young and middle-aged patients with stroke are also affected by FT, which can exacerbate their physical and psychological challenges. Understanding the patient’s experience and response measures can further understand the impact of FT on patients with stroke, to help alleviate FT. However, little is known concerning the experience of patients with stroke with FT or their coping strategies. Therefore, this study aimed to describe the experiences of FT in young and middle-aged patients with stroke and their coping strategies.MethodsA phenomenological method was utilized. Semi-structured interviews were conducted with 21 young and middle-aged stroke patients (aged 18–59) between October 2022 and March 2023. The participants were recruited from a tertiary hospital in Shanghai, China. The research team used NVivo 12.0 software. Giorgi’s phenomenological analysis method was used to analyse the interview data.ResultsThe interview results were divided into two categories in terms of patients’ experiences of FT and their coping strategies. Nine subthemes were constructed. The experience category included four subthemes: (1) taking on multifaceted economic pressure, (2) dual choice of treatment, (3) decline in material living standards, and (4) suffering from negative emotions such as anxiety and depression. The coping strategy category included five subthemes: (1) reducing expenses, (2) improving living habits, (3) proactive participation in medical decision-making, (4) making a job position choice, and (5) seeking social support.ConclusionsFT in young and middle-aged patients with stroke, which affected their physical and mental health, led them to implement strategies for dealing with FT. The Chinese government needs to broaden the reach of health insurance coverage and advance the fairness of healthcare policies. Healthcare professionals must pay active attention to FT in such patients in terms of strengthening their health education and considering their needs and preferences. Patients need to improve their sense of self-efficacy, actively reintegrate into society, and adhere to rehabilitation and treatment. Individuals at a high risk of stroke are recommended to purchase health insurance. Multifaceted efforts are needed to reduce the impact of FT in young and middle-aged patients with stroke.

In Vivo Bioassay of the Repellent Activity of Caraway Essential Oil against Green Peach Aphid.

An in vivo dual choice bioassay with white cabbage as a host plant was used to determine the repellent effect of three different accessions of caraway (Carum carvi L.) essential oils (EOs) against the green peach aphid Myzus persicae (Sulzer). The dominant components of the EO were D-Carvone (47.3-74.4%) and D-limonene (25.2-51.9%), which accounted for 99.2-99.5% of the EOs determined by GC/MS. The EO with the highest D-limonene content (51.9%) showed the highest repellence (Repellency Index (RI) = +41%), which was stable up to 330 min. The incorporation of several surfactants with different hydrophilic-lipophilic balance values (from 12.4 to 16.7) with caraway EO caused a general inhibition of the repellent effect during the testing period (RI from +41% to -19%). Overall, the findings indicate that caraway EO could be used as a green peach aphid repellent, but more work is needed to formulate the EO into a ready-to-use product.

Susceptibility of Rhyzopertha dominica (Coleoptera: Bostrichidae) and Sitophilus oryzae (Coleoptera: Curculionidae) to the fungal entomopathogen Beauveria bassiana (Balsamo-Crivelli) Vuillemin s.l. (Hypocreales: Clavicipitaceae)

Control measures of stored grain pests include the excessive utilization of chemical insecticides that generate negative environmental impact. Current trends in integrated pest management are oriented towards the preservation of the environment using natural biopesticides, among these products arise entomopathogenic fungi. This study aimed to test the efficacy of a native strain of Beauveria bassiana to control two main stored grain pests such as Sitophilus oryzae and Rhyzopertha dominica and also evaluate the persistence of the fungus on wheat grains. The B. bassiana strain controlled 89%±0.07 of R. dominica adults and 80% ±0.14 of S. oryzae. The survival analysis showed that MST was 4.27 ±0.19 days for R. dominica adults and 4.27 ±0.20 days for S. oryzae. Furthermore, results of long rank test for the comparison of the Kaplan-Meier curves did not present significant differences between the survival of both stored grain pests. Dual choice tests demonstrated that B. bassiana LPSc1227 presented a repellent action against both stored grain pests. The seed persistence of conidia was 100% in treated seeds after 45 days. Further research will contribute to elucidate more insecticidal features of the B. bassiana LPSc 1227 strain against S. oryzae and R. dominica, two main stored grain insect pests. Highlights: bassiana presented insecticidal activity against R. dominica and S. oryzae. bassiana demonstrated a repellent action against both stored grain pests. bassiana was able to persist on the surface of wheat grains after 45 days storage.

Chemotactic responses and parasitism of Trichogramma pretiosum after successive generations in Spodoptera frugiperda

AbstractTrichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) is an important parasitoid of lepidopteran pests. Its parasitism success is related to its foraging behavior, mediated by kairomones from its hosts. We aimed to evaluate the chemotactic responses and parasitism of T. pretiosum from Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) eggs as well as the parasitoid maintained for three generations in Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) eggs. Chemotactic responses of T. pretiosum from both hosts were evaluated in a dual choice olfactometer. Females were submitted to a choice between washed vs. unwashed eggs of E. kuehniella or S. frugiperda, as well as to unwashed eggs of both hosts. Egg extracts of both hosts were also contrasted with hexane and with each other. Parasitism of T. pretiosum exposed to eggs of the two species was also evaluated. Females from E. kuehniella were more attracted to odors from eggs of this host whenever it was present. Third generation parasitoids from S. frugiperda eggs were more attracted to eggs and egg extract of S. frugiperda than to those from E. kuehniella. The highest number of parasitized eggs and emerged parasitoids in S. frugiperda was observed in parasitoids coming from the third generation in this host. Therefore, imaginal conditioning could be an alternative to be considered for T. pretiosum learning before releasing, possibly optimizing its search and parasitism process in S. frugiperda eggs.

Nature to Nurture: Chitosan nanopowder a natural carbohydrate polymer choice of egg parasitoid, Trichogramma Japonicum Ashmead

Chitosan is a naturally occurring linear biopolymer made of partially deacetylated acetyl and N-acetyl glucosamine. Its biocompatible physiochemical and biochemical properties are unmatched. Chitosan is transformed to nanopowder for use in agriculture and associated industries as nanocarriers for existing agrochemicals, ensuring the delayed release of chemicals with better solubility. Chitosan nanopowder applied to leaves or soil can activate a plant's natural defences against insects and pathogens. These studies were carried out because there is a potential for toxicological risk linked with products created utilizing nanotechnology, such as chitosan nanopowder, and therefore researchers felt the need to investigate this. The egg parasitoides Trichogramma Japonicum Ashmead was used as a low-cost biomarker to determine the potential toxicity of chitosan nanopowder. This study looked into the possibility that the adult stage of the egg parasitoids, Trichogramma Japonicum Ashmead might be negatively impacted by chitosan nanopowder (80–100 nm). Unpaired t-test statistical analysis has been carried out. According to the statistical analysis, host eggs exposed to chitosan nanopowder showed noticeably greater parasitization than the control group. As a natural supply of carbohydrate polymers chitosan nanopowder promotes the parasitization of T. Japonicum. The findings showed that T. Japonicum favoured chitosan nanopowder. Through Y dual choice, eight-arm multiple choice, and no-choice olfactometer experiments, as well as images from a stereozoom microscope and a scanning electron microscope (SEM), the data was thoroughly supported. Future agricultural applications of chitosan nanopowder will benefit from a deeper understanding of our findings.

Blueberries infected with the fungal pathogen Colletotrichum fioriniae release odors that repel Drosophila suzukii.

Spotted-wing drosophila, Drosophila suzukii, is a serious pest of thin-skinned fruits. Alternative methods to control this pest are needed to reduce insecticide use, including new repellents. Previous research demonstrated that D. suzukii adults use odor cues to avoid blueberries infected with the fungal pathogen Colletotrichum fioriniae, which causes the disease anthracnose. To identify novel D. suzukii repellents, we investigated the volatile emission from experimentally-infected fruit, which were inoculated with C. fioriniae isolates in the laboratory, and from field-collected fruit, which were naturally infected and harvested from a field. We then tested the pathogen-induced volatiles on D. suzukii adult behavior. Volatile emission was similar between all five C. fioriniae strains, with good agreement between experimentally-infected and field-collected berries. In total, 14 volatiles were found to be more abundant in infected versus uninfected fruit headspace. In multiple-choice bioassays, nine of the 14 volatiles elicited repellency responses from adult D. suzukii. These nine volatiles were further evaluated in dual choice assays, where all nine reduced fly capture by 43-96% compared to the control. The most repellent compounds tested were the esters ethyl butanoate and ethyl (E)-but-2-enoate, which were more or equally repellent to the known D. suzukii repellents 1-octen-3-ol, geosmin, and 2-pentylfuran. Dose-response assays identified concentration-dependent effects on D. suzukii repellency and oviposition when applied individually and consistent aversion observed across doses of a 1:1 blend. We report two repellents from C. fioriniae-infected blueberries that could be useful semiochemicals for the behavioral manipulation of D. suzukii in the field. © 2023 Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Companion crops alter olfactory responses of the fall armyworm (Spodoptera frugiperda) and its larval endoparasitoid (Cotesia icipe)

BackgroundThe fall armyworm (FAW), Spodoptera frugiperda, is a devastating invasive pest and a threat to food security in Africa, with yield losses of 20–50%. Recent studies highlighted the importance of cereal crops such as maize and sorghum as the most preferred host plants for FAW oviposition. In the current work, we investigated the olfactory responses of FAW and its key larval endoparasitoid Cotesia icipe to odours from the preferred host (maize) in the presence of six potential companion crops including beans, groundnut, sweet potato, greenleaf- and silverleaf desmodium, and cassava. We hypothesized that odours released by companion crops in maize-based intercropping systems would alter host preferences of FAW for oviposition and its parasitoid responses.ResultsIn dual choice oviposition bioassays, FAW laid significantly more eggs on maize than on the other plants. However, in the multiple-choice bioassays, significantly fewer eggs were laid on maize when companion plants were present except cassava. While wind tunnel bioassays confirmed the differential behavioural responses of FAW, we found that its larval endoparasitoid C. icipe was attracted to volatiles from the companion plants tested individually and/or when they were combined with maize. Coupled gas chromatography–mass spectrometry (GC–MS) analysis detected several potential behaviour-modifying compounds including (Z)-3-hexenyl acetate, (E)-β-ocimene, (E)-4,8-dimethyl-1,3,7-nonatriene, (E)-β-caryophyllene, camphor, methyl salicylate and (E, E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene.ConclusionsOur findings provide evidence supporting diversified maize cropping system could reduce FAW damage by repelling the pest while simultaneously recruiting its natural enemies. Hence, diversifying cereal cropping system with companion crops could serve as an ecologically sustainable FAW management strategy.Graphical

The MTego trap: a potential tool for monitoring malaria and arbovirus vectors

BackgroundOdour-baited traps are useful for vector surveillance and control. However, most existing traps have shown inconsistent recapture rates across different mosquito species, necessitating the need for more effective and efficient traps. The MTego trap with integrated thermal stimuli has been developed as an alternative trap. This study was undertaken to determine and compare the efficacy of the MTego trap to that of the Biogents (BG) modular BG-Pro (BGP) trap for sampling different mosquito species in a semi-field system.MethodsFully balanced Latin square design experiments (no-choice and dual choice) were conducted in semi-field chambers using laboratory-reared female Anopheles gambiae sensu stricto, Anopheles funestus, Anopheles arabiensis, Culex quinquefasciatus and Aedes aegypti. There were 16 replicates, and 50 mosquitoes of each species were released in each chamber per replicate. The evaluated traps were as follows: the MTego trap baited with PM6 (MT-PM6), the MTego trap baited with BG-Lure (BGL) (MT-BGL), and the BGP trap baited with BG-Lure (BGP-BGL).ResultsIn the no-choice test, the MT-BGL and BGP-BGL traps captured a similar proportion of An. gambiae (31% vs 29%, P-value = 0.519) and An. funestus (32% vs 33%, P = 0.520). The MT-PM6 and BGP-BGL traps showed no significant difference in capturing Ae. aegypti (33% vs 31%, P = 0.324). However, the BGP-BGL caught more An. arabiensis and Cx. quinquefasciatus mosquitoes than the other traps (P < 0.0001). In the dual-choice test of MT-PM6 vs BGP-BGL, similar proportions of An. funestus (25% vs 27%, P = 0.473) and Ae. aegypti (29% vs 25%, P = 0.264) were captured in the traps, while the BGP-BGL captured more An. gambiae, An. arabiensis and Cx. quinquefasciatus mosquitoes than the MT-PM6 (P < 0.0001).ConclusionsThis study demonstrated that the MTego trap has potential as a tool that can be used interchangeably with the BGP trap for sampling anthropophilic mosquitoes including African malaria vectors An. gambiae and An. funestus and the principal arbovirus vector Ae. aegypti.Graphical abstract

The influence of manure-based organic fertilisers on the oviposition behaviour of Anopheles arabiensis

The rice agroecosystem provides suitable breeding habitat for many malaria vector species, and rice-adjacent communities are consequently exposed to a greater malaria transmission risk than non-rice-associated communities. As part of efforts to expand rice production in Africa, sustainable and climate-adapted practices such as the System of Rice Intensification (SRI) are being promoted. SRI encourages the use of organic fertilisers (OFs) such as cow and chicken dung, as opposed to inorganic industrially produced fertilisers, due to their lower resource cost, apparent benefit to the rice agroecosystem and as a means to reduce the greenhouse gas emissions associated with the production of industrial fertilisers. However, the impact of OFs on mosquito fauna is not well documented and may have knock-on consequences on malaria transmission risk. Here, we demonstrate, using dual choice egg count assays, that both cow and chicken dung modulate the oviposition behaviour of Anopheles arabiensis, a major malaria vector in Sub-Saharan Africa. A significantly reduced proportion of eggs were laid in water treated with either cow or chicken dung compared to untreated water, with higher dung concentrations resulting in further reduced proportions. When presented in competition, significantly fewer eggs were laid in water treated with chicken dung than with cow dung. Moreover, there was no evidence of egg retention in any experiment, including in no-choice experiments where only dung-containing dishes were available. These results suggest both cow and chicken dung may act as oviposition deterrents to malaria vector species and that the application of manure-based OFs in rice agriculture may modulate the oviposition behaviour of An. gambiae s.l. within agroecosystems. Quantification of the ammonia present in dung-infused water showed higher concentrations were present in the chicken dung infusion, which may be one contributing factor to the difference in observed deterrence between the two dung types. Deterrence of mosquito oviposition in OF-treated farms may potentially affect the overall production of malaria vectors within rice fields and their contribution to local malaria transmission.

Elucidating the insecticidal mechanisms of zein nanoparticles on Anticarsia gemmatalis (Lepidoptera: Erebidae).

Previous research suggested that positively charged zein nanoparticles [(+)ZNP] were toxic to neonates of Anticarsia gemmatalis Hübner and deleterious to noctuid pests. However, specific modes of action for ZNP have not been elucidated. Diet overlay bioassays attempted to rule out the hypothesis that A. gemmatalis mortality was caused by surface charges from component surfactants. Overlay bioassays indicated that negatively charged zein nanoparticles [(-)ZNP] and its anionic surfactant, sodium dodecyl sulfate (SDS), exhibited no toxic effects when compared to the untreated check. Nonionic zein nanoparticles [(N)ZNP] appeared to increase mortality compared to the untreated check, though larval weights were unaffected. Overlay results for (+)ZNP and its cationic surfactant, didodecyldimethylammonium bromide (DDAB), were found to be consistent with former research indicating high mortalities, and thus, dosage response curves were conducted. Concentration response tests found the LC50 for DDAB on A. gemmatalis neonates was 208.82 a.i./ml. To rule out possible antifeedant capabilities, dual choice assays were conducted. Results indicated that neither DDAB nor (+)ZNP were antifeedants, while SDS reduced feeding when compared to other treatment solutions. Oxidative stress was tested as a possible mode of action, with antioxidant levels used as a proxy for reactive oxygen species (ROS) in A. gemmatalis neonates, which were fed diet treated with different concentrations of (+)ZNP and DDAB. Results indicated that both (+)ZNP and DDAB decreased antioxidant levels compared to the untreated check, suggesting that both (+)ZNP and DDAB may inhibit antioxidant levels. This paper adds to the literature on potential modes of action by biopolymeric nanoparticles.

Response of some mango-infesting fruit flies to aqueous solutions of the basil plant Ocimum tenuiflorum L

IntroductionHorticulture is an important sub-sector for many African countries. Tephritid fruit flies continue to cause serious direct and indirect damage to the sub-sector. The male annihilation technique (MAT) using methyl eugenol (ME) is among the most revered techniques in fruit fly management. However, ME-based lures are only available to some farmers in Africa. Several basils of the genus Ocimum produce ME.MethodsIn laboratory experiments, we used a dual choice olfactometer to assess the attraction of adult oriental fruit fly Bactrocera dorsalis to intact plants, 100 µL commercial methyl eugenol (ME) (positive control), 10 mg/mL of O. tenuiflorum aqueous extract (Otae), and a negative control (blank). Large arena experiments were conducted to compare the responses of four fruit fly species of economic importance in Africa to Otae-baited traps.ResultsIn dual choice olfactometer assay, more B. dorsalis males (78.6%) than females (23.8%) were attracted to Otae. Most B. dorsalis males were attracted to the positive control (90.5%) and 10 mg/mL Otae (88.5%) compared to the whole plant (84.0%). In large arena experiments, Otae attracted the most B. dorsalis males (47.7%), followed by Zeugodacus cucurbitae males (25.1%), while males of Ceratitis species were the least attracted. The analysis of headspace volatiles from aerial plants, Otae and essential oil using gas chromatography-mass spectrometry detected 97 compounds. The intact plant without flowers, intact plant with flowers, Otae, and the O. tenuiflorum essential oil contributed 76, 62, 33 and 28 compounds, respectively. ME comprised the top three most abundant compounds, especially in the essential oil.DiscussionOur study confirms the potential of O. tenuiflorum as a source of ME for tephritid fruit fly integrated management in Africa. Otae, a readily available alternative to commercial ME, can be used to develop fruit fly-baited traps, particularly for smallholder farmers.

Chikungunya Virus Infection and Gonotrophic Cycle Shape Aedes aegypti Oviposition Behavior and Preferences.

Targeting gravid females through chemical lures is a promising strategy in vector control; however, it requires the understanding of the factors susceptible to alter female oviposition behavior. Here, we evaluated the effect of infection with chikungunya virus (CHIKV) and the number of gonotrophic cycles (GCs) on oviposition activity in A. aegypti. Dual choice oviposition assays were performed, where dodecanoic acid, pentadecanoic acid, n-heneicosane and a Sargasssum fluitans (Børgesen) Børgesen extract were tested in uninfected females and females infected with CHIKV, at the 1st and 2nd GC. Infected females displayed a lower percentage of oviposition and a higher number of eggs laid at the 1st GC. Then, the combined effects of GC and CHIKV were observed on oviposition preferences, with a chemical-dependent effect. For instance, the deterrent effect of n-heneicosane and pentadecanoic acid increased at the 2nd GC in infected females. These results allow for a deeper understanding of the mechanisms involved in oviposition site selection and highlight the need for taking into account physiological stage changes to increase the control programs' efficacy.

Oviposition and olfactometry response of codling moth (Cydia pomonella) to quince (Cydonia oblonga) cultivars

AbstractQuince (Cydonia oblonga Miller) is one of the common hosts of the codling moth, Cydia pomonella L. Knowledge of the chemical ecology of codling moth is based on its behaviour against apples and pears but not quince. Here, we present a laboratory study on olfactometry and oviposition behavior preference of mated females and neonate larvae of codling moth against four quince cultivars. Oviposition of mated females was evaluated on dual‐choice test, whereas olfactometry response was evaluated in a Y‐tube olfactometer. Neonate larvae were evaluated in a dual‐choice test between pieces of fruit of quince cultivars in pairwise comparisons. In the Y‐tube olfactometer assay, mated females always responded positively to the fruit‐scented arm to quince fruit volatiles. Smyrna and Champion cultivars showed significant differences in the time that mated females spent in the fruit‐scented arm. In the oviposition assay, all pairwise comparisons showed significant differences in the number of the eggs laid, with Smyrna and Champion being the cultivars most preferred. No significant differences were detected in dual choice of neonate larvae. All comparisons elicited the behaviour of contacting the fruit source. Based on the potential emission of recognized kairomones and the results found here, cultivars Smyrna and Champion are suggested as cultivars most susceptible to codling moth infestation.

Cigarettes smoking and e-cigarettes using among university students: a cross-section survey in Guangzhou, China, 2021

BackgroundThere is an increase in the use of cigarettes and e-cigarettes worldwide, and the similar trends may be observed in young adults. Since 2014, e-cigarettes have become the most commonly used nicotine products among young adults (Sun et al., JAMA Netw Open 4:e2118788, 2021). With the increase in e-cigarette use and the decrease in use of cigarettes and other tobacco products, however, there is limited information about Chinese smokers, e-cigarettes users and trends in cigarettes and e-cigarettes use among university students. Therefore, our objective was to investigate the using status of cigarettes, e-cigarettes and smoking behavior among the students from 7 universities in Guangzhou, China.MethodsStudents at 7 different universities in Guangzhou were investigated online in 2021 through a cross-sectional survey. A total of 10,008 students were recruited and after screening, 9361 participants were adopted in our statistics. Descriptive analysis, Chi-square analysis, and multiple logistic regression analysis were used to explore the smoking status and influencing factors.ResultsThe average age of the 9361 university students was 22.4 years (SD = 3.6). 58.3% of participants were male. 29.8% of the participants smoked or used e-cigarettes. Among the smokers and users of e-cigarettes, 16.7% were e-cigarettes only users, 35.0% were cigarettes only users, and 48.3% were dual users.Males were more likely to smoke or use e-cigarettes. Medical students, students from prestigious Chinese universities, and students with higher levels of education were less likely. Students with unhealthy lifestyles (e.g., drinking alcohol frequently, playing video games excessively, staying up late frequently) were more likely to smoke or use e-cigarettes. Emotion can have significant impacts on both cigarettes and e-cigarettes dual users when choosing cigarettes or e-cigarettes to use. More than half of dual users said they would choose cigarettes when they were depressed and e-cigarettes when they were happy.ConclusionWe identified factors influencing the use of cigarettes and e-cigarettes among university students in Guangzhou, China. Gender, education level background, specialization, lifestyle habits and emotion all influenced the use of cigarettes and e-cigarettes among university students in Guangzhou, China. Male, low education level, from non-prestigious Chinese universities or vocational schools, non-medical specialization, and presence of unhealthy lifestyles were influencing factors for the use of cigarettes and e-cigarettes among university students in Guangzhou and students with these factors were more likely to smoke or use e-cigarettes. Besides, emotions can influence dual users' choice of products.This study provides more information to better understand young people's preferences for cigarettes and e-cigarettes by elucidating the characteristics of cigarettes and e-cigarettes use, as well as related influencing factors, among university students in Guangzhou. Further research involving more variables connected to the use of cigarettes and e-cigarettes will be required in our future study.

Drosophila Free-Flight Odor Tracking is Altered in a Sex-Specific Manner By Preimaginal Sensory Exposure.

In insects such as Drosophila melanogaster, flight guidance is based on converging sensory information provided by several modalities, including chemoperception. Drosophila flies are particularly attracted by complex odors constituting volatile molecules from yeast, pheromones and microbe-metabolized food. Based on a recent study revealing that adult male courtship behavior can be affected by early preimaginal exposure to maternally transmitted egg factors, we wondered whether a similar exposure could affect free-flight odor tracking in flies of both sexes. Our main experiment consisted of testing flies differently conditioned during preimaginal development in a wind tunnel. Each fly was presented with a dual choice of food labeled by groups of each sex of D. melanogaster or D. simulans flies. The combined effect of food with the cis-vaccenyl acetate pheromone (cVA), which is involved in aggregation behavior, was also measured. Moreover, we used the headspace method to determine the "odorant" identity of the different labeled foods tested. We also measured the antennal electrophysiological response to cVA in females and males resulting from the different preimaginal conditioning procedures. Our data indicate that flies differentially modulated their flight response (take off, flight duration, food landing and preference) according to sex, conditioning and food choice. Our headspace analysis revealed that many food-derived volatile molecules diverged between sexes and species. Antennal responses to cVA showed clear sex-specific variation for conditioned flies but not for control flies. In summary, our study indicates that preimaginal conditioning can affect Drosophila free flight behavior in a sex-specific manner.

Magnetic monopoles with no strings attached: a portal to the dark side of dual electrodynamics

It has long been known that in the absence of electric charges and currents, Maxwell’s electromagnetism in 4 dimensional vacuum Minkowski space-time is invariant under SO(2) dual transformations that mix its electric and magnetic fields. Extending this symmetry to include the coupling to electrically charged matter, requires a dual coupling to magnetically charged matter as well, leading to Maxwell equations for SO(2) dual electrodynamics. Based on a doubled ensemble of SO(2) dual 4-vector gauge potentials which does away with the need of Dirac string singularities for magnetic monopoles, a local Lagrangian action principle for SO(2) dual electromagnetism is known, which manifestly displays all the required space-time and internal symmetries, and reduces to the experimentally well established Maxwell electrodynamics in the absence of magnetic charges and currents. Applying the same considerations for the matter action of electrically and magnetically charged point particles, a unique SO(2) dual generalised Lorentz force is identified for SO(2) dual electrodynamics, truly different from the usual SO(2) dual invariant choice motivated by simplicity, but yet made arbitrarily and which does not derive from some action principle. This generalised Lorentz force involves a single real and new coupling constant of unknown value, without the requirement of a Dirac–Schwinger–Zwanziger quantisation condition for electric and magnetic charges of dyons. A physical consequence for SO(2) dual electrodynamics of this coupling constant if nonvanishing, is to open a channel, or portal between the otherwise mutually totally “dark” sectors of electric and magnetic charges for electromagnetic interactions.

Cotton plants as ideal models for teaching and research on inducible direct plant defenses

Cotton (Gossypium hirsutum) stores defensive compounds in glands covering its leaves and other tissues. The density and the chemical filling of these glands increase systematically in developing leaves in response to herbivory on older leaves. Cotton seedlings are known to respond more strongly to actual caterpillar herbivory than to mere physical damage. It is not clear whether this amplified response is linked to insect-derived elicitors or difference in damage properties. To investigate this, we assessed the effect of repeated artificial damage without and with application of regurgitant from Spodoptera exigua caterpillars. Repeated mechanical damage led to a systemic increase of gland density, gland size, and content of defensive terpenes, with no detectable additional elicitation upon regurgitant treatment. Dual choice feeding assays further showed that defense induction triggered by just physical damage made newly developing leaves far less palatable to S. exigua larvae as compared to leaves from undamaged seedlings, whereas they did not distinguish between leaves from damaged plants treated with or without regurgitant. Our study confirms that the systemic induction of cotton glands is an unspecific response to physical damage, although cotton is known to respond to caterpillar-associated elicitors for other defensive traits. Cotton glands induction can be readily visualized under modest magnification, making the experiments described in this study highly suited to teach chemical ecology and aspects of plant defense theory in practical classes.