Addition of Selected Plant-Derived Semiochemicals to Yellow Sticky Traps Does Not Improve Citrus Psyllid Captures.

Fast and effective monitoring and surveillance techniques are crucial for the swift implementation of control methods to prevent the spread of Huanglongbing, a devastating citrus disease, and its invasive psyllid vector, Asian citrus psyllid, Diaphorina citri, into South Africa, as well as to control the native vector, African citrus triozid, Trioza erytreae. Monitoring for citrus psyllid pests can be improved by using semiochemical odorants to augment already visually attractive yellow sticky traps. However, environmental variables such as temperature and humidity could influence odorant release rates. Five field cages were used to test the ability of a selection of odorants to improve yellow sticky trap efficacy in capturing citrus psyllids. Environmental effects on odorant loss from the dispensers were also investigated. The odorants that most improved yellow sticky trap captures in field cages were then tested under open field conditions alongside lower concentrations of those same lures. Gas chromatography-mass spectrometry was used to calculate odorant release rates as well as to determine if any contamination occurred under field conditions. None of the odorants under field cage or field conditions significantly improved psyllid capture on yellow sticky traps. Temperature influenced odorant loss, and release rate from polyethylene bulbs decreased over time. Based on these results, the use of unbaited yellow sticky traps seems to be the most effective method for monitoring of Huanglongbing vectors.

Expression of honey bee (Apis mellifera) sterol homeostasis genes in food jelly producing glands of workers.

Adult workers of Western honey bees (Apis mellifera L.) acquire sterols from their pollen diet. These food sterols are transported by the hemolymph to peripheral tissues such as the mandibular and the hypopharyngeal glands in the worker bees' heads that secrete food jelly which is fed to developing larvae. As sterols are obligatory components of biological membranes and essential precursors for molting hormone synthesis in insects, they are indispensable to normal larval development. Thus, the study of sterol delivery to larvae is important for a full understanding of honey bee larval nutrition and development. Whereas hypopharyngeal glands only require sterols for their membrane integrity, mandibular glands add sterols, primarily 24-methylenecholesterol, to its secretion. For this, sterols must be transported through the glandular epithelial cells. We have analyzed for the first time in A. mellifera the expression of genes which are involved in intracellular movement of sterols. Mandibular and hypopharyngeal glands were dissected from newly emerged bees, 6-day-old nurse bees that feed larvae and 26-day-old forager bees. The expression of seven genes involved in intracellular sterol metabolism was measured with quantitative real-time PCR. Relative transcript abundance of sterol metabolism genes was significantly influenced by the age of workers and specific genes but not by gland type. Newly emerged bees had significantly more transcripts for six out of seven genes than older bees indicating that the bulk of the proteins needed for sterol metabolism are produced directly after emergence.

Ribose-cysteine and levodopa abrogate Parkinsonism via the regulation of neurochemical and redox activities in alpha-synuclein transgenic Drosophila melanogaster models.

Parkinson's disease (PD), the most prevalent type of parkinsonism, is a progressive neurodegenerative condition marked by several non-motor and motor symptoms. PD is thought to have a complex aetiology that includes a combination of age, genetic predisposition, and environmental factors. Increased expression of α-synuclein (α-Syn) protein is central to the evolvement of neuropathology in this devastating disorder, but the potential of ribose-cysteine and levodopa in abating pathophysiologic changes in PD model is unknown. Crosses were set up between flies conditionally expressing a pathological variant of human α-Syn (UAS-α-Syn) and those expressing GAL4 in neurons (elav-GAL4) to generate offspring referred to as PD flies. Flies were randomly assigned to five groups (n = 40) from the total population of flies, with each group having five replicates. Groups of PD flies were treated with either 500 mg/kg ribose-cysteine diet, 250 mg/kg levodopa diet, or a combination of the two compounds for 21 days, whereas the control group (w1118) and the PD group were exposed to a diet without ribose-cysteine or levodopa. In addition to various biochemical and neurochemical assays, longevity, larval motility, and gravitaxis assays were carried out. Locomotive capability, lifespan, fecundity, antioxidant state, and neurotransmitter systems were all significantly (p < 0.05) compromised by overexpression of α-Syn. However, flies treated both ribose cysteine and levodopa showed an overall marked improvement in motor functions, lifespan, fecundity, antioxidant status, and neurotransmitter system functions. In conclusion, ribose-cysteine and levodopa, both singly and in combination, potentiated a therapeutic effect on alpha-synuclein transgenic Drosophila melanogaster models of Parkinsonism.

Unmasking diphtheria in Nigeria: A multifaceted approach to tackle outbreaks and improve immunization rates among the Nigerian population-An updated correspondence.

Background and aims: The World Health Organization has recently declared the frequent outbreaks of diphtheria in Nigeria as a public health concern. Although vaccination efforts have been successful in Nigeria, unfortunately, the recent 2023 outbreak in Nigeria has been nothing short of distressing. Of course, cases of diphtheria incidence are under-reported in Nigeria. This present article aims to proffer a possible multifaceted approach to tackle outbreaks of diphtheria in Nigeria and improve immunization rates against the disease among the Nigerian population. Methods: In writing this study, literature search was done about diphtheria in Nigeria using the following keywords: "diphtheria, prevalence, vaccination, efforts, challenges, and Nigeria" on PubMed, Web of Science, Google Scholar, and ResearchGate within 10 years. Result: This study found that an estimated seven million people remain unvaccinated and are at risk for infection in the country, especially people living in the Northern part of the country. Between the June 30 and August 31, 2023, Nigeria recorded an unusual increase in the number of confirmed cases of diphtheria, where a total of 5898 suspected cases were reported from 59 local government areas in 11 states across Nigeria. The majority (99.4%) of suspected cases of the disease were reported from six states: Kano (1816), Katsina (234), Yobe (158), Bauchi (79), Kaduna (45), and Borno (33). Conclusion: If Nigeria is to emerge beyond these frequent epidemics of diphtheria, the Nigerian government must work on tackling this issue on multiple fronts simultaneously, that is, at the national and international levels, as we believe that these levels would give a holistic way to unmask diphtheria in Nigeria.

ACCEPTANCE AND UTILIZATION OF MODERN FAMILY PLANNING METHODS AMONG WOMEN OF CHILD BEARING AGE IN RURAL COMMUNITIES OF NORTH-EASTERN NIGERIA.

Introduction: Modern family planning is one of the most "health-promoting" and cost-effective activities in public health promotion and has the potential to avert approximately 30% of maternal and 10% of child deaths. Family planning is an important preventive measure against maternal and child morbidity and mortality. It is an essential component of primary health care and reproductive health. It confers important health and development benefits to individuals, families, communities, and the nation at large. Objectives: The study examined the acceptance and utilization of modern family planning methods among women of childbearing age in Potiskum town of Yobe State, North-eastern Nigeria. Methodology: A descriptive cross-sectional study design was adopted for the study. A semi-structured questionnaire was used to collect data from 271 respondents comprising women of childbearing age (15-49 years) residing in Bolewa 'B', Yerimaram, and DogoNini wards of Potiskum town, Yobe State. A multi-stage sampling technique was used to select the participants for the study. Results: The findings of the study revealed that the women of child-bearing age in Potiskum town, Yobe State have a high level of knowledge on modern family planning methods (88.6%) with friends and relatives as the predominant source of information (60.4%). More than half of the respondents (54.2%) have good utilization of modern family planning with cultural and religious misconceptions playing vital roles. The unmet needs were found to be (37.4%). Established determinants of utilization of modern family planning services among the respondents include male noninvolvement, side effects, religion, and distance beyond 5km to a health facility. Conclusion: In conclusion, despite a good level of knowledge of modern contraceptives among the respondents, only half utilize the services. It is recommended among others that, there is a need for the government, through the Ministry of Health, to revive and support family planning education at both household and community levels that targets the woman and her partner. This could be undertaken through community mobilization and engagement using print and mass media, traditional leaders, community resource groups, market places as well as newsletters, posters, and social media.

KNOWLEDGE, ATTITUDE AND PRACTICE OF PREMARITAL SCREENING FOR HIV/AIDS AMONG RESIDENCE OF RURAL AREAS IN NORTH-EASTERN NIGERIA.

Introduction: One of the biggest health challenges threatening the human race in recent times is the HIV/AIDS pandemic. To know one's HIV status is a part of the human right to health. The disease has continued to be on the front burner for many years now, despite initial denials and cover-ups by some countries. Sub-Saharan Africa with just over 10 percent of the world's population has the greatest burden of this disease. It is estimated that close to two-thirds of all people living with HIV are in sub-Saharan Africa with South Africa having the highest number. Objective: This study assessed the knowledge, attitude, and practice of premarital screening of HIV/AIDS among residents of rural areas of Itas Gadau local government area of Bauchi state, North-eastern Nigeria. Methodology: A descriptive cross-sectional design was used for the study. A semi-structured questionnaire was used to collect data from 379 eligible respondents comprising residents of Itas and Gadau towns of Bauchi State. A multi-stage sampling procedure was used to select the participants for the study. Pearson's chi-square test was used in testing for the association between educational status and premarital screening for HIV/AIDS in rural areas. Results: The results show that all (100%) of the respondents have heard of HIV/AIDS and the dominant source of information was from friends (77.6%) followed by healthcare workers (17.4%). In addition, 90% of participants have good knowledge of premarital screening for HIV/AIDS. Majority of the study respondents had undergone premarital screening for HIV/AIDS (64.4%). The result also shows that there is a statistically significant relationship between educational status and the practice of premarital screening for HIV/AIDS in Itas/Gadau, Bauchi State with p-value of 0.001. Conclusion: The study found that there was a very high level of knowledge, good attitude, and practice for HIV/AIDS among the study respondents. Thus we recommend that the community should maintain the mandatory premarital screening and continue with regular health education on premarital screening for HIV/AIDS.

Revising the essential package of health services through stakeholder alignment, Somalia.

Problem: The fragmented health sector in Somalia, burdened by financial challenges and an inadequate regulatory system, struggles to provide equitable essential health services to the entire population. Approach: To revise an essential package of health services that stakeholders could support and that aligned with stakeholders' financial and technical resources, the federal health ministry invited all key stakeholders in 2020 to participate in the revision process of the essential package. The ministry distributed a concept note to invited stakeholders, describing the scope and purpose of the revision process of the essential package. The note also contained a timeline and the expected contribution of each stakeholder. Stakeholders nominated representatives based on their technical expertise and knowledge of the health sector in Somalia. Local setting: The health sector in Somalia involves multiple stakeholders, including the health ministry and many development partners. The private sector plays a substantial role in health-care provision. Public spending is an estimated 17% of the total health expenditure. Relevant changes: After an 18-month revision process, the health ministry and development partners agreed to prioritize high-impact, cost-effective services and use a progressive realization of the package to improve access and coverage. The implementation strategy considers the health system and operational capacity of service providers, particularly in security-compromised areas. Lessons learnt: The approach showed that inclusivity, collaboration and transparency were of importance for a successful revision of the package. These achievements in consensus-building and priority alignment advance the government's pursuit of equitable and comprehensive health care for all.

Differences in the suitability of published honey bee (Apis mellifera) reference genes between the African subspecies Apis mellifera scutellata and European derived Apis mellifera.

Quantitative real-time polymerase chain reaction (qPCR) is a method widely used to determine changes and differences in gene expression. As target gene expression is most often quantified relative to the expression of reference genes, the validation of suitable reference genes is of critical importance. In practice, however, such validation might not be thoroughly conducted if the same species and the same tissue or body parts are used for qPCR experiments. Here we show, that qPCR reference genes published for workers of European honey bee (Apis mellifera) subspecies fail to be stably expressed in workers of the African subspecies Apis mellifera scutellata. This is the case even when the sampled workers are in the same life stage, the same organ was dissected and the same reagents were used. Thus, reference genes need to be thoroughly re-tested before they can be used as suitable references even when the only thing that changes is the subspecies used.

Mandibular glands secrete 24-methylenecholesterol into honey bee (Apis mellifera) food jelly.

Honey bee (Apis mellifera) workers feed their larvae with food jelly that is secreted by specialized glands in their heads - the hypopharyngeal and the mandibular glands. Food jelly contains all the nutrients the larvae need to develop into adult honey bees, including essential dietary sterols. The main sterol in food jelly, 24-methylenecholesterol (24MC), is pollen-derived and delivered in food jelly to the larvae in a complex with two proteins, major royal jelly protein 1 (MRJP1) and apisim. Whereas the proteins are synthesized in the hypopharyngeal glands, the sterol-secreting gland has not been identified. We here identified the mandibular glands as sterol-secreting gland for food jelly production by direct detection of the four main honey bee sterols (24MC, campesterol, ß-sitosterol and isofucosterol). Furthermore, 24MC seems to be specifically enriched in the mandibular glands, thereby ensuring that food jelly contains the amounts of 24MC necessary for complex formation with MRJP1 and apisimin.

Delayed enterocutaneous fistula after 17 years of gunshot wound injury: a case report.

Enterocutaneous fistula (ECF) is a common complication of abdominal surgery. Postoperatively, it may be the result of a small intestinal injury or an anastomosis leak, and it typically manifests days or weeks following surgery. Case presentation: A 56-year-old man with a history of a gunshot wound injury in the abdomen with colon injury managed for colocolic anastomosis 17 years earlier presented to our hospital's general surgery clinic with the complaint of drainage at the scar area. It was discovered that he had an ECF. The patient underwent a laparotomy. Fistula tract excision and segmental colon resection with colocolic anastomosis were done. Clinical discussion: ECF formation after an extraordinarily long latency due to an anastomotic leak, which has not been previously documented in the literature, is a distinctive aspect of the case. As a result, surgeons should consider ECF in their differentials for patients with a history of abdominal operations. Conclusion: Surgical management is the definitive treatment of ECF after proper resuscitation and stabilization of the patient's condition. Preoperative imaging is crucial for determining the anatomy of the fistula and any associated intra-abdominal pathology.

Switched step integral backstepping control for nonlinear motion systems with application to a laboratory helicopter.

In this paper, the energy efficiency of the widespread application of backstepping control to a class of nonlinear motion systems is investigated. A Switched Step Integral Backstepping Control (SSIBC) scheme is introduced to improve immunity to measurement noise and to increase the energy efficiency of conventional backstepping in practice. The SSIBC is realized by switching between two candidate controllers obtained at different steps of the iterative backstepping design process. A bi-state dependent hysteresis rule is developed to supervise stable switching between the different regimes in the presence of noise. The proposed method is experimentally verified on a MIMO twin rotor laboratory helicopter involving coupled nonlinear dynamics, inaccessible states and uncertainties. Experimental results show that in addition to a reduction in power consumption, the SSIBC reduces saturation of the control signal and visible motor jerking in contrast with conventional backstepping. Additional comparisons with a previously proposed optimized decoupling PID controller also show significant improvement in precision achieved with higher energy efficiency. Experimental results obtained with the introduction of an external disturbance into the system also show the robustness of the proposed SSIBC.

Spatial distribution of Glossina morsitans (Diptera: Glossinidae) in Zambia: A vehicle-mounted sticky trap survey and Maxent species distribution model.

BACKGROUND: Tsetse-transmitted African trypanosomiasis is a debilitating and fatal disease of humans and livestock if left untreated. While knowledge of the spatial distribution patterns of tsetse is essential for the development of risk-based vector control strategies, existing distribution maps in Zambia are more than 40 years old and were based on coarse spatial resolution data. The recently developed vehicle-mounted sticky trap (VST) provides an alternative sampling device to aid in updating existing distribution maps but has not been applied outside an experimental setting and is limited to motorable tracks. Therefore, the objective of the present study was to demonstrate the effectiveness of utilizing the VST for area-wide surveys of Glossina morsitans and to use the occurrence records to predict its spatial distribution in Zambia under current environmental conditions using Maxent. METHODOLOGY/PRINCIPAL FINDINGS: Two-sided all-blue VST baited with butanone and 1-octen-3-ol was used to survey 692 and 1020 km of transect routes in G. m. centralis Machado and G. m. morsitans Westwood previously published distribution in Zambia. Maxent species distribution technique was used to predict the potential distribution of the two subspecies using current climatic and environmental data which was then compared to the historical distribution. A total of 15,602 tsetse were captured with G. m. morsitans (58%) being the most abundant. G. m. centralis and G. pallidipes Austin represented 39 and 2% of the catch respectively, and G. brevipalpis Newstead was also detected. The predicted potential distribution for G. m. centralis was 80,863 km2 while that of G. m. morsitans was 70,490 km2 representing a 47 and 29% reduction compared to their historical distributions, respectively. CONCLUSION/SIGNIFICANCE: The VST is effective for sampling G. morsitans outside experimental settings and is recommended for use as an additional tsetse survey tool. The spatial distribution of G. morsitans in Zambia has reduced by 101,051 km2 due to temperature and land cover changes.

Seasonal and elevational changes of plant-pollinator interaction networks in East African mountains.

Across an elevation gradient, several biotic and abiotic factors influence community assemblages of interacting species leading to a shift in species distribution, functioning, and ultimately topologies of species interaction networks. However, empirical studies of climate-driven seasonal and elevational changes in plant-pollinator networks are rare, particularly in tropical ecosystems. Eastern Afromontane Biodiversity Hotspots in Kenya, East Africa. We recorded plant-bee interactions at 50 study sites between 515 and 2600 m asl for a full year, following all four major seasons in this region. We analysed elevational and seasonal network patterns using generalised additive models (GAMs) and quantified the influence of climate, floral resource availability, and bee diversity on network structures using a multimodel inference framework. We recorded 16,741 interactions among 186 bee and 314 plant species of which a majority involved interactions with honeybees. We found that nestedness and bee species specialisation of plant-bee interaction networks increased with elevation and that the relationships were consistent in the cold-dry and warm-wet seasons respectively. Link rewiring increased in the warm-wet season with elevation but remained indifferent in the cold-dry seasons. Conversely, network modularity and plant species were more specialised at lower elevations during both the cold-dry and warm-wet seasons, with higher values observed during the warm-wet seasons. We found flower and bee species diversity and abundance rather than direct effects of climate variables to best predict modularity, specialisation, and link rewiring in plant-bee-interaction networks. This study highlights changes in network architectures with elevation suggesting a potential sensitivity of plant-bee interactions with climate warming and changes in rainfall patterns along the elevation gradients of the Eastern Afromontane Biodiversity Hotspot.

Changes in axonal and clinical function during intravenous and subcutaneous immunoglobulin therapy in chronic inflammatory demyelinating polyneuropathy.

BACKGROUND AND AIMS: Intravenous immunoglobulin (IVIg) has a rapid clinical effect which cannot be explained by remyelination during each treatment cycle in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). This study aimed to investigate axonal membrane properties during the IVIg treatment cycle and their potential correlation with clinically relevant functional measurements. METHODS: Motor nerve excitability testing (NET) of the median nerve was performed before and 4 and 18 days after initiation of an IVIg treatment cycle in 13 treatment-naïve (early) CIDP patients and 24 CIDP patients with long term (late) IVIg treatment, 12 CIDP patients treated with subcutaneous immunoglobulin (SCIg) and 55 healthy controls. Clinical function was measured extensively using the Six Spot Step test, 10-Meter Walk test, 9-Hole Peg test, grip strength, MRC sum score, Overall Neuropathy Limitations Score and Patient Global Impression of Change. RESULTS: Superexcitability and S2 accommodation decreased significantly in the early treatment group from baseline to day 4 and returned to baseline levels at day 18, suggesting temporary depolarization of the axonal membrane. A similar trend was observed for the late IVIg group. Substantial clinical improvement was observed in both early and late IVIg groups during the entire treatment cycle. No statistically significant correlation was found between clinical and NET changes. No change was found in NET or clinical function in the SCIg group or controls. INTERPRETATION: NET suggested temporary depolarization of the axonal membrane during IVIg treatment in treatment naïve CIDP patients. The relation to clinical improvement, however, remains speculative.

A Printed Reconfigurable Monopole Antenna Based on a Novel Metamaterial Structures for 5G Applications.

A novel antenna structure is constructed from cascading multi-stage metamaterial (MTM) unit cells-based printed monopole antenna for 5G mobile communication networks. The proposed antenna is constructed from a printed conductive trace that fetches four MTM unit cells through four T-Resonators (TR) structures. Such a combination is introduced to enhance the antenna gain-bandwidth products at sub-6GHz bands after exiting the antenna with a coplanar waveguide (CPW) feed. The antenna circuitry is fabricated by etching a copper layer that is mounted on Taconic RF-43 substrate. Therefore, the proposed antenna occupies an effective area of 51 × 24 mm2. The proposed antenna provides an acceptable matching impedance with S11 ≤ -10 dB at 3.7 GHz, 4.6 GHz, 5.2 GHz, and 5.9 GHz. The antenna radiation patterns are evaluated at the frequency bands of interest with a gain average of 9.1-11.6 dBi. Later, to control the antenna performance, four optical switches based on LDR resistors are applied to control the antenna gain at 5.85 GHz, which is found to vary from 2 dBi to 11.6 dBi after varying the value of the LDR resistance from 700 Ω to 0 Ω, in descending manner. It is found that the proposed antenna provides an acceptable bit error rate (BER) with varying the antenna gain in a very acceptable manner in comparison to the ideal performance. Finally, the proposed antenna is fabricated to be tested experimentally in in free space and in close to the human body for portable applications.

Optically Remote Control of Miniaturized 3D Reconfigurable CRLH Printed Self-Powered MIMO Antenna Array for 5G Applications.

A novel design of a reconfigurable MIMO antenna array of a 3D geometry-based solar cell integration that is operating at sub-6 GHz for self-power applications in a 5G modern wireless communication network. The proposed antenna array provides three main frequency bands around 3.6 GHz, 3.9 GHz, and 4.9 GHz, with excellent matching impedance of S11 ≤ -10 dB. The proposed MIMO array is constructed from four antenna elements arranged on a cubical structure to provide a low mutual coupling, below -20 dB, over all frequency bands of interest. Each antenna element is excited with a coplanar waveguide (CPW). The proposed radiation patterns are controlled with two optical switches of Light Dependent Resistors (LDRs). The proposed antenna array is fabricated and tested experimentally in terms of S-parameters, gain and radiation patterns. The maximum gain is found to be 3.6 dBi, 6.9 dBi, and 3.5 dBi at 3.6 GHz, 3.9 GHz, and 4.9 GHz, respectively. It is realized that the proposed array realizes a significant beam forming by splitting the antenna beam and changing the main lobe direction at 3.9 GHz after changing LDR switching statuses. Such an antenna array is found to be very applicable for femtocell wireless communication networks in the 5G systems.

Community detection in networks by dynamical optimal transport formulation.

Detecting communities in networks is important in various domains of applications. While a variety of methods exist to perform this task, recent efforts propose Optimal Transport (OT) principles combined with the geometric notion of Ollivier-Ricci curvature to classify nodes into groups by rigorously comparing the information encoded into nodes' neighborhoods. We present an OT-based approach that exploits recent advances in OT theory to allow tuning between different transportation regimes. This allows for better control of the information shared between nodes' neighborhoods. As a result, our model can flexibly capture different types of network structures and thus increase performance accuracy in recovering communities, compared to standard OT-based formulations. We test the performance of our algorithm on both synthetic and real networks, achieving a comparable or better performance than other OT-based methods in the former case, while finding communities that better represent node metadata in real data. This pushes further our understanding of geometric approaches in their ability to capture patterns in complex networks.

Serological and molecular epidemiology of leptospirosis and the role of dogs as sentinel for human infection in Nigeria.

Objective: Prospective cross-sectional study of dogs in Nigeria to study leptospirosis, inferred to be endemic in all regions of the country by researchers. Aim is to generate empirical updated evidence of leptospiral infection and delineate serovars involved. Methods: Study determined the sero-prevalence and infection rate in 342 dogs using sero-assays, culture isolation and novel qPCR. In-house designed primers targeting conserved regions were used to amplify genes in quantitative Real-Time PCR (qRT-PCR) for leptospiral detection to serogroups. Molecular analysis of the leptospiral 16S rRNA and LipL32 genes were used for identification of pathogenic Leptospira species. Primers targeting the O-antigen (rfb) region of the Leptospira lipopolysaccharide (LPS) were used for differentiating serovars based on comparative melting temperature (Tm) analysis against reference serogroups. Results: Overall serological and bacteriological prevalence of 56 (16.4%) and 40 (11.7%) respectively was recorded. Vaccination, ages and season(s) were the strongest determinants of infection. Unvaccinated animals, stray dogs and symptomatic dogs presented statistically significant (P < 0.05) higher risk of infection: OR 25.531 (6.108, 106.712; 95% CI). Discussion: The evidence suggests 1 of every 10 dogs is infected and could be symptomatic for the disease or a carrier of leptospires in the studied region in Nigeria with attendant public health risks.

The Endophyte Trichoderma asperellum M2RT4 Induces the Systemic Release of Methyl Salicylate and (Z)-jasmone in Tomato Plant Affecting Host Location and Herbivory of Tuta absoluta.

The use of endophytic fungi has dramatically increased plant performance through the enhancement of plant protection against abiotic and biotic stressors. We previously demonstrated that the endophytic fungus Trichoderma asperellum M2RT4 improves tomato defenses against the tomato leafminer Tuta absoluta through the reduction of oviposition, leafmining, pupation, and adult emergence. However, the underlying mechanism by which the presence of this endophytic fungus within tomato host plant affects T. absoluta host selection and life-history traits is unknown. We tested the behavioral responses of T. absoluta in Y-tube olfactometer bioassays and found that females preferred non-inoculated tomato plants against those inoculated by endophytes. Additionally, T. absoluta females were not attracted to non-inoculated infested nor to inoculated-infested tomato plants. Chemical analysis revealed the emission of methyl salicylate in inoculated tomato plant and an increase in the amounts of monoterpenes emitted from non-inoculated infested plants. Additionally, we found that upon herbivory, T. asperellum M2RT4 modulates tomato plant chemistry through the production of (Z)-jasmone thus activating both salicylic and jasmonic acid defense pathways. Further, T. absoluta females were attracted to monoterpernes including α-pinene, 2-carene, and ß-phellandrene but repelled by methyl salicylate. Methyl salicylate could therefore be considered as a good semiochemical-based candidate for sustainable T. absoluta management using a "push-pull" approach. However, in dose-response bioassays, females of T. absoluta did not show any preference to the four component-blend (α-pinene, 2-carene, ß-phellandrene, and methyl salicylate). (Z)-jasmone-treated tomato leaflets significantly reduced the leafmining activity of the pest at the concentration of 10 ng/µL and causing the highest larval mortality rate (83%) with the shortest LT50 (1.73 days) 7 days post-treatment. T. asperellum M2RT4 effect on herbivore performance was then (Z)-jasmone-mediated. These findings expand our understanding of how the endophytic fungus T. asperellum M2RT4 could mediate chemical interactions between T. absoluta and its host plant which are potentially important for development of environmentally friendly T. absoluta management programs.