RESUMO
Food insecurity and malnutrition have reached critical levels with increased human population, climate fluctuations, water shortage; therefore, higher-yielding crops are in the spotlight of numerous studies. Abiotic factors affect the yield of staple food crops; among all, wheat stem sawfly (Cephus cinctus Norton) and orange wheat blossom midge (Sitodiplosis mosellana) are two of the most economically and agronomically harmful insect pests which cause yield loss in cereals, especially in wheat in North America. There is no effective strategy for suppressing this pest damage yet, and only the plants with intrinsic tolerance mechanisms such as solid stem phenotypes for WSS and antixenosis and/or antibiosis mechanisms for OWBM can limit damage. A major QTL and a causal gene for WSS resistance were previously identified in wheat, and 3 major QTLs and a causal gene for OWBM resistance. Here, we present a comparative analysis of coding and non-coding features of these loci of wheat across important cereal crops, barley, rye, oat, and rice. This research paves the way for our cloning and editing of additional WSS and OWBM tolerance gene(s), proteins, and metabolites.
Assuntos
Dípteros/patogenicidade , Resistência à Doença/genética , Genoma de Planta , Himenópteros/patogenicidade , Doenças das Plantas/genética , Locos de Características Quantitativas , Triticum/genética , Animais , Avena/genética , Avena/imunologia , Avena/parasitologia , Mapeamento Cromossômico/métodos , Dípteros/fisiologia , Grão Comestível , Código Genético , Hordeum/genética , Hordeum/imunologia , Hordeum/parasitologia , Humanos , Himenópteros/fisiologia , Oryza/genética , Oryza/imunologia , Oryza/parasitologia , Doenças das Plantas/imunologia , Doenças das Plantas/parasitologia , Característica Quantitativa Herdável , Secale/genética , Secale/imunologia , Secale/parasitologia , Especificidade da Espécie , Triticum/imunologia , Triticum/parasitologiaRESUMO
Fopius arisanus (Sonan), an egg-pupal parasitoid of numerous fruit fly species, was recently introduced into Africa for the control of the Oriental fruit fly, Bactrocera dorsalis (Hendel). In this study, life-table data of F. arisanus were generated under laboratory conditions at six constant temperatures (15, 20, 25, 30, 28 and 35 °C; 75% RH, L12:D12 photoperiod) and under variable conditions in a screenhouse on B. dorsalis. Several non-linear functions were fitted to model species development, mortality, longevity and oviposition using the Insect Life Cycle Modeling (ILCYM) software. The established phenology models were stochastically simulated at variable temperatures to estimate the life table parameters. Fopius arisanus completed development from egg to adult at all the temperatures tested except at 35 °C. Mean developmental time from egg to adult was inversely proportional to the temperature. The minimum temperature threshold (Tmin) from egg to adult was 8.15 °C, while the maximum temperature threshold (Tmax) was estimated at 34.2 °C. The optimal temperature for immature stages survival was predicted for 20-30 °C. The optimum fecundity estimated was 251 eggs/female at 22 °C. Following the stochastic simulations under natural conditions of the selected agro-ecological zones, it appears that the Humid Forest with Bimodal Rainfall provides a suitable thermal condition for potential population growth of F. arisanus. The present study shows the importance of temperature on the demographic parameters of F. arisanus. Implications of present findings on the biological control of B. dorsalis under climate change scenarios is discussed.
Assuntos
Himenópteros/fisiologia , Controle Biológico de Vetores , Tephritidae/parasitologia , Termotolerância , Animais , Temperatura Corporal , Himenópteros/crescimento & desenvolvimento , Himenópteros/patogenicidade , OviposiçãoRESUMO
Different factitious hosts were used to mass rear Trichogramma japonicum Ashmead in different parts of the globe because thorough details were lacking in both the laboratory and the field. The objective of this study was to compare, parasitoid, T. japonicum reared in different factitious hosts. Three commonly used factitious host eggs, Corcyra cephalonica (Stainton), Ephestia kuehniella Zeller and Sitotroga cerealella Olivier were tested under laboratory conditions and then in the field over a yellow stem borer, Scirpophaga incertulus (Walker) of rice. The highest parasitism by T. japonicum was observed on E. kuehniella eggs. The parasitoid's highest emergence (88.99%) was observed on S. cerealella eggs at 24 h exposure, whereas at 48 h it was on E. kuehniella eggs (94.66%). Trichogramma japonicum females that emerged from E. kuehniella eggs were significantly long-lived. The days of oviposition by hosts and the host species were significant individually, but not their interaction. Higher proportions of flying T. japonicum were observed when reared on E. kuehniella and C. cephalonica eggs. Field results showed that T. japonicum mass-reared on E. kuehniella showed higher parasitism of its natural host, S. incertulus eggs. Hence, by considering these biological characteristics and field results, E. kuehniella could be leveraged for the mass rearing of quality parasitoids of T. japonicum in India, the Asian continent and beyond.
Assuntos
Interações Hospedeiro-Parasita/genética , Himenópteros/genética , Lepidópteros/parasitologia , Controle Biológico de Vetores , Animais , Ovos/parasitologia , Feminino , Especificidade de Hospedeiro/genética , Himenópteros/patogenicidade , Índia , Larva/patogenicidade , Lepidópteros/genética , Mariposas/parasitologia , Oryza/parasitologia , Oviposição/genética , Vespas/patogenicidadeRESUMO
The egg parasitoid Trichogramma evanescens Westwood is considered as an efficient biological control agent for managing several lepidopteran pests and it is widely distributed throughout the world. Mass rearing protocols of parasitoids that are currently in use in biocontrol programs require a meticulous quality control plan, in order to optimize their efficacy, but also their progeny production capacity. In this paper, the effect of different factors on the quality control in mass rearing of T. evenescens, using Plodia interpunctella (Hübner) and Galleria mellonella L. as host species, were investigated. The impact of egg agewas significant in the rates of parasitism, for both host species tested. Significantly highest percent of parasitoid emergence was noticed in two day-old eggs for both host species, while one day-old eggs day exhibited the maximum emergence when both species were used togetherin the same trials. Age-dependent storage egg preservation at either 4 or 9°C significantly influenced the parasitism percentages on both species. The highest parasitism percentage was recorded in two day-old G. mellonella eggs that are kept for 15 days at 9°C while the lower in one day-old P. interpunctella eggs for 60 d storage. Moreover, the highest parasitoid mortality was recorded in T. evanescens reared either on P. interpunctella or G. mellonella at 20°C. Rearing of the parasitoid on a mixture of eggs of both host species resulted in higher parasitism, but not always in higher rates of parasitoid emergence. The results of the present work provide useful information that can be further utilized in rearing protocols of T. evanescens.
Assuntos
Criopreservação , Himenópteros/genética , Controle Biológico de Vetores , Simbiose/genética , Animais , Agentes de Controle Biológico , Ovos/parasitologia , Especificidade de Hospedeiro/genética , Himenópteros/patogenicidade , Lepidópteros/parasitologia , Lepidópteros/patogenicidade , Mariposas/parasitologia , Vespas/parasitologiaRESUMO
The presence of three species of the genus Anagyrus Howard (Hymenoptera: Encyrtidae) parasitizing the obscure mealybug Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae) in agricultural ecosystems of citrus, persimmon and ornamental plants from Eastern Spain is recorded. Anagyrus aligarhensis Agarwal Alam is recorded for the first time as parasitoid on this mealybug. Anagyrus fusciventris (Girault) is a new record for Spain. Anagyrus borrianensis sp. nov., reared as a specific primary parasitoid of this mealybug, is described and illustrated. The joint presence of Anagyrus pseudococci (Girault) and Anagyrus vladimiri Triapitsyn on citrus crops is confirmed. A key to species of Anagyrus parasitoids of Planococcus and Pseudococcus mealybugs in Eastern Spain is provided.
Assuntos
Citrus , Hemípteros/parasitologia , Himenópteros/classificação , Animais , Ecossistema , Himenópteros/patogenicidade , EspanhaRESUMO
Classical biological control is a pest control tool involving the release of imported natural enemies. The Sterile Insect Technique (SIT) comprises releasing sexually sterile insects of a pest into the wild population for suppression or eradication. Both these approaches are environmentally friendly and their combination can result in a synergistic impact on pest populations and improve eradication. However, stringent regulation surrounding the introduction of biological control agents limits their use in eradication owing to the perceived risk of effects on non-target organisms. We investigated the irradiation biology of the egg parasitoid Trissolcus basalis to ascertain whether sterile parasitoids could mitigate the risk of potential sustained non-target impacts. Mated female T. basalis were gamma-irradiated at doses between 120 and 150 Gy and exposed to egg masses of their host Nezara viridula throughout their lifespans. This resulted in host mortality, despite a substantial reduction in developing parasitoid offspring, which followed a negative dose-response. There was no emergence of parasitoid offspring at 140 Gy and above. Irradiation did not affect oviposition behaviour but caused an increase in longevity. Consequently, sterile parasitoids could possibly alleviate concerns regarding the irreversibility of biological control release, which promotes further investigation of their potential role in eradication.
Assuntos
Infertilidade Feminina/patologia , Infertilidade/genética , Longevidade/efeitos da radiação , Óvulo/efeitos da radiação , Controle Biológico de Vetores , Animais , Feminino , Raios gama , Heterópteros/patogenicidade , Heterópteros/efeitos da radiação , Interações Hospedeiro-Parasita/efeitos da radiação , Himenópteros/patogenicidade , Himenópteros/efeitos da radiação , Infertilidade/patologia , Infertilidade Feminina/etiologia , Oviposição/efeitos da radiação , Óvulo/patologiaRESUMO
Introduction: Annona macroprophyllata Donn. Smith. (Annonaceae) (syn. Annona diversifolia Saff.) is a valued fruit tree species known as papausa. In Mexico and Central America, this fruit has become an important crop because of its tasty flavor and high pulp content. Its fruits are frequently damaged by the incidence of wasps of the genus Bephratelloides Girault (Hymenoptera: Eurytomidae), which develop inside the seeds. Objective: To report the interaction of Bephratelloides cubensis Ashmead during its life cycle in fruits of A. macroprophyllata. Methods: We periodically collected fruits in different states of growth recording a) oviposition, b) the moment of evident infection, c) the development of the wasps inside the seeds, and d) their emergence as adults. We also determined the proportion of damaged fruits and seeds. Results: The data indicate that wasps preferred to oviposit on fruits with a diameter of less than 8 cm, oviposition was more frequent between 11:00 am and 03:00 pm., and there was 26 % infestation of fruits, and 9 % of seeds. Conclusion: It is an obligatory interaction for the wasp, the highest proportion of attack on fruits was in the early stages of fruit development and control actions should focus on the protection of these early stages.
Introducción: Annona macroprophyllata Donn. Smith. (Annonaceae) es una especie de árbol frutal, conocida como papausa. En México y América Central, esta fruta se ha convertido en un cultivo importante y valorado debido a su delicioso sabor y la cremosa textura de su pulpa. Sus frutos son frecuentemente dañados por la incidencia de avispas del género Bephratelloides Girault (Hymenoptera: Eurytomidae), que se desarrollan dentro de las semillas. Objetivo: Describir la interacción de Bephratelloides cubensis Ashmead durante su ciclo de vida en frutos de A. macroprophyllata. Método: Recolectamos frutos en diferentes estados de crecimiento registrando a) la ovoposición, b) el momento de la infección evidente, c) el desarrollo de las avispas dentro de las semillas, y d) su emergencia como adultos. También determinamos la proporción de frutas y semillas dañadas. Resultados: Los datos indican que las avispas preferían ovipositar en frutas con un diámetro de menos de 8 cm, la oviposición era más frecuente entre las 11:00 a.m. y las 3:00 p.m., y que había un 26 % de la infestación en las frutas y un 9 % en semillas. Conclusión: Es una interacción obligada para la avispa y la mayor proporción de ataque a los frutos fue en las etapas tempranas de desarrollo de frutos y las acciones de control se deberían enfocar a la protección de estas etapas.
Assuntos
Animais , Annona/parasitologia , Himenópteros/patogenicidade , Oviposição , Vespas , AnnonaceaeRESUMO
A parasitoid's decision to reject or accept a potential host is fundamental to its fitness. Superparasitism, in which more than one egg of a given parasitoid species can deposit in a single host, is usually considered sub-optimal in systems where the host is able to support the development of only a single parasitoid. It follows that selection pressure may drive the capacity for parasitoids to recognize parasitized hosts, especially if there is a fitness cost of superparasitism. Here, we used microsatellite studies of two distinct populations of Cotesia vestalis to demonstrate that an egg laid into a diamondback moth (Plutella xylostella) larva that was parasitized by a conspecific parasitoid 10 min, 2 or 6 h previously was as likely to develop and emerge successfully as was the first-laid egg. Consistent with this, a naive parasitoid encountering its first host was equally likely to accept a healthy larva as one parasitized 10 min prior, though handling time of parasitized hosts was extended. For second and third host encounters, parasitized hosts were less readily accepted than healthy larvae. If 12 h elapsed between parasitism events, the second-laid egg was much less likely to develop. Discrimination between parasitized and healthy hosts was evident when females were allowed physical contact with hosts, and healthy hosts were rendered less acceptable by manual injection of parasitoid venom into their hemolymph. Collectively, these results show a limited capacity to discriminate parasitized from healthy larvae despite a viability cost associated with failing to avoid superparasitism.
Assuntos
Genética Populacional , Interações Hospedeiro-Parasita/genética , Mariposas/parasitologia , Seleção Genética/genética , Animais , Aptidão Genética/genética , Himenópteros/genética , Himenópteros/patogenicidade , Repetições de Microssatélites/genética , Mariposas/genética , Oviposição/genética , Óvulo/parasitologiaRESUMO
PURPOSE OF REVIEW: In Hymenoptera venom allergy, the research focus has moved from whole venoms to individual allergenic molecules. Api m 10 (icarapin) has been described as a major allergen of honeybee venom (HBV) with potentially high relevance for diagnostics and therapy of venom allergy. Here, we review recent studies on Api m 10 characteristics as well as its role in component-resolved diagnostics and potential implications for venom-specific immunotherapy (VIT). RECENT FINDINGS: Api m 10 is a major allergen of low abundance in HBV. It is an obviously unstable protein of unknown function that exhibits homologs in other insect species. Despite its low abundance in HBV, 35 to 72% of HBV-allergic patients show relevant sensitization to this allergen. Api m 10 is a marker allergen for HBV sensitization, which in many cases can help to identify primary sensitization to HBV and, hence, to discriminate between genuine sensitization and cross-reactivity. Moreover, Api m 10 might support personalized risk stratification in VIT, as dominant sensitization to Api m 10 has been identified as risk factor for treatment failure. This might be of particular importance since Api m 10 is strongly underrepresented in some therapeutic preparations commonly used for VIT. Although the role of Api m 10 in HBV allergy and tolerance induction during VIT is not fully understood, it certainly is a useful tool to unravel primary sensitization and individual sensitization profiles in component-resolved diagnostics (CRD). Moreover, a potential of Api m 10 to contribute to personalized treatment strategies in HBV allergy is emerging.
Assuntos
Alérgenos/uso terapêutico , Venenos de Artrópodes/uso terapêutico , Venenos de Abelha/uso terapêutico , Dessensibilização Imunológica/métodos , Himenópteros/patogenicidade , Mordeduras e Picadas de Insetos/terapia , Animais , Venenos de Artrópodes/farmacologia , Venenos de Abelha/farmacologia , Humanos , Fatores de RiscoRESUMO
BACKGROUND: Hymenoptera venom allergy (HVA) is of great concern because of the possibility of anaphylaxis, which may be fatal. Venom immunotherapy (VIT) is the only disease-modifying treatment in HVA and, although efficient, its mechanism remains partially unknown. Gene expression analysis may be helpful for establishing a proper model of tolerance induction during the build-up phase of VIT. The present study aimed to analyze how the start of VIT changes the expression of 15 selected genes. METHODS: Forty-five patients starting VIT with a wasp venom allergy were enrolled. The diagnosis was established based on anaphylaxis history (third or fourth grade on the Mueller scale) and positive soluble immunoglobulin E and/or skin tests. Two blood collections were performed in the patient group: before and after 3 months of VIT. One sample was taken in the control group. Gene expression analysis was performed using a reverse transcriptase-polymerase chain reaction with microfluidic cards and normalized to the 18S housekeeping gene. RESULTS: Commd8 was the only gene that changed expression significantly after the start of VIT (p = 0.012). Its expression decreased towards the levels observed in the healthy controls. Twelve out of 15 genes (commd8, cldn1, cngb3, fads1, hes6, hla-drb5, htr3b, prlr, slc16a4, snx33, socs3 and twist2) revealed a significantly different expression compared to the healthy controls. CONCLUSIONS: The present study shows that commd8 changes significantly its expression during initial phase of VIT. This gene might be a candidate for VIT biomarker in future studies.
Assuntos
Biomarcadores/metabolismo , Dessensibilização Imunológica/métodos , Himenópteros/imunologia , Hipersensibilidade Imediata/terapia , Mordeduras e Picadas de Insetos/terapia , Venenos de Vespas/uso terapêutico , Vespas/imunologia , Adolescente , Adulto , Idoso , Animais , Estudos de Casos e Controles , Dessaturase de Ácido Graxo Delta-5 , Feminino , Perfilação da Expressão Gênica , Humanos , Himenópteros/patogenicidade , Hipersensibilidade Imediata/etiologia , Hipersensibilidade Imediata/metabolismo , Imunoglobulina E/imunologia , Mordeduras e Picadas de Insetos/complicações , Mordeduras e Picadas de Insetos/metabolismo , Masculino , Pessoa de Meia-Idade , Prognóstico , Testes Cutâneos , Adulto JovemRESUMO
Trichogramma leucaniae is believed to be an efficient biological control agent for controlling the soybean pod borer [SPB; Leguminivora glycinivorella]. The large eggs of Chinese oak silkworm, Antheraea pernyi, are one of the best alternative host for mass production of Trichogramma. However, they are considered poor host for the growth and development of T. leucaniae. Here, we determine the feasibility of successive rearings of T. leucaniae on the large eggs for eight generations and evaluated their capacity of parasitizing SPB eggs of different ages. In the first four generations, the suitability of T. leucaniae reared on large eggs exhibited a significant increasing tendency and then decreased with the successive generations thereafter. The percentage of parasitized eggs and number of emerged adults per egg were increased from 40.0% and 10.8 adults/egg in F1 generation to 86.7% and 36.4 adults/egg in F4 generation respectively. In addition, T. leucaniae reared on A. pernyi for four generations significantly parasitized more SPB eggs regardless of egg age compared with those reared on Corcyra cephalonica eggs. These results provided useful information on the feasibility of mass production of T. leucaniae by reared for successive generations on A. pernyi large eggs.
Assuntos
Bombyx/parasitologia , Ovos/parasitologia , Himenópteros/crescimento & desenvolvimento , Controle Biológico de Vetores/métodos , Animais , Feminino , Interações Hospedeiro-Parasita , Humanos , Himenópteros/patogenicidade , Masculino , Óvulo/parasitologia , Glycine max/parasitologiaRESUMO
Plants respond to insect infestation with defenses targeting insect eggs on their leaves and the feeding insects. Upon perceiving cues indicating imminent herbivory, such as damage-induced leaf odors emitted by neighboring plants, they are able to prime their defenses against feeding insects. Yet it remains unknown whether plants can amplify their defenses against insect eggs by responding to cues indicating imminent egg deposition. Here, we tested the hypothesis that a plant strengthens its defenses against insect eggs by responding to insect sex pheromones. Our study shows that preexposure of Pinus sylvestris to pine sawfly sex pheromones reduces the survival rate of subsequently laid sawfly eggs. Exposure to pheromones does not significantly affect the pine needle water content, but results in increased needle hydrogen peroxide concentrations and increased expression of defense-related pine genes such as SOD (superoxide dismutase), LOX (lipoxygenase), PAL (phenylalanine ammonia lyase), and PR-1 (pathogenesis related protein 1) after egg deposition. These results support our hypothesis that plant responses to sex pheromones emitted by an herbivorous insect can boost plant defensive responses to insect egg deposition, thus highlighting the ability of a plant to mobilize its defenses very early against an initial phase of insect attack, the egg deposition.
Assuntos
Interações Hospedeiro-Parasita/imunologia , Himenópteros/patogenicidade , Óvulo/imunologia , Pinus sylvestris/imunologia , Atrativos Sexuais/imunologia , Animais , Feminino , Herbivoria/fisiologia , Peróxido de Hidrogênio/imunologia , Peróxido de Hidrogênio/metabolismo , Himenópteros/fisiologia , Masculino , Odorantes , Oviposição/imunologia , Pinus sylvestris/parasitologia , Folhas de Planta/imunologia , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Proteínas de Plantas/imunologia , Proteínas de Plantas/metabolismo , Atrativos Sexuais/metabolismoRESUMO
Summary: Hymenoptera venom allergy (HVA) is the most frequent cause of anaphylaxis in Europe, accounting for most of the severe reactions occurring in adults, and being the second cause of anaphylaxis in children. Prevention of further episodes in patients who developed a systemic reaction (SR) is based on the correct management of the allergic emergency, the referral to an allergist for a correct diagnosis, prescription of adrenaline auto-injectors (AAI) and specific venom immunotherapy (VIT), if recommended. Diagnosis is based on the classification of the type of reaction, confirmation of an IgE-mediated pathogenesis and the identification of the offending insect. The use of component resolved diagnostics may be helpful in case of poly-sensitization or negative allergy tests with a proven history of previous SRs. When a severe SR occurs, baseline serum tryptase levels should always be assessed. The prescription of AAI is recommended or suggested for untreated patients, patients undergoing VIT and after discontinuation of treatment, according to multiple evidence. VIT is the most effective treatment available for HVA patients, as confirmed by recent European guidelines. VIT has an early, sustained and persistent protective effect and modifies the natural course of the disease. Moreover, VIT proved to be safe and well tolerated. According to a recent systematic review, no treatment-related fatalities were recorded to date. Compared to AAI, VIT significantly improves the quality of life of HVA patients by reducing the anxiety and limitations in daily activities caused by the fear of stinging insects. The memory of a life-threatening experience is the most likely reason why adherence to VIT is higher compared to immunotherapy with inhalant allergens. Several risk factors in HVA have been identified that can influence not only the severity of sting reactions in untreated patents, but also the occurrence of side effects, treatment effectiveness and the risk of relapse after discontinuation of VIT. Patient and treatment-related risk factors must be considered while selecting the best candidates for VIT, the type and duration of treatment. In this paper we address the most important issues related to HVA and VIT that may have an impact on daily clinical practice.
Assuntos
Anafilaxia/patologia , Venenos de Artrópodes/imunologia , Himenópteros/imunologia , Mordeduras e Picadas de Insetos/imunologia , Alérgenos/imunologia , Animais , Dessensibilização Imunológica/métodos , Epinefrina/uso terapêutico , Humanos , Himenópteros/patogenicidade , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Triptases/sangueRESUMO
Pachycrepoideus vindemmiae is a wasp that parasitizes and host-feeds on pupae of the invasive spotted-wing drosophila (SWD, Drosophila suzukii). Few studies have addressed interactions between these two species and little is known about the potential of this parasitoid as a biocontrol agent of SWD and the different variables that may affect it. Here, we investigated the impact of extrinsic and intrinsic factors on life-history traits of P. vindemmiae. Both constant (entire adulthood) and limited (30 minutes) supplies of water + honey, honey, or host increased parasitoid survival compared to controls (water or fasting). Water + honey caused the highest parasitoid survivals (35-60 days), independent of supply period, sex, and host availability. Females were intrinsically more resistant to water- and honey-deprivation than males, and host-feeding elevated such resistance even higher. Constant honey supply (either with or without water) supported the highest host-killing capacities (= capacity to kill hosts) (ca. 600 SWD pupae/wasp). However, in young females (4-9 days old), the impact of honey availability (with or without water) was insignificant while water deprivation (either with or without honey) caused the highest host-killing potential. This indicates that although sugar becomes a critical nutritional resource as females age, young females depend more on water than sugar to reproduce. Neither water nor honey affected the sex ratio of young females, but when we considered the entire adulthood, the availability of honey caused the lowest proportion of females (0.50), independent of water availability. Neither water nor honey affected parasitoid emergence rate (0.97), independent of female age. Based on survival and host-killing capacity, we conclude that P. vindemmiae has a tremendous biocontrol potential against SWD. Both limited and constant supply of water, sugar, and host increase parasitoid survival, while constant supply of water and/or honey enhance its host-killing potential and decrease sex ratio depending on maternal age.
Assuntos
Drosophila/parasitologia , Interações Hospedeiro-Parasita/fisiologia , Himenópteros/patogenicidade , Reprodução/fisiologia , Animais , Drosophila/metabolismo , Drosophila/fisiologia , Feminino , Mel , Himenópteros/metabolismo , Himenópteros/fisiologia , Masculino , Pupa/parasitologia , Pupa/fisiologia , Razão de Masculinidade , Açúcares/metabolismo , Asas de Animais/fisiologiaRESUMO
Introduction: Many risk factors that facilitate venom allergy and increase systemic reaction severity have been described in various studies, but the data are limited regarding this issue. We aimed to evaluate the impact of total immunoglobulin E (tIgE), specific IgE, and tryptase levels on the severity of systemic reactions in patients with a history of allergic reactions to Hymenoptera stings. Method: Eighty-two patients with a history of allergic reaction to Hymenoptera venom admitted to our outpatient clinic between March 2016 and August 2017 were included. Venom-specific IgE (Apis mellifera and Vespula vulgaris), total IgE, and basal tryptase levels were measured. Skin-prick tests were performed with inhalant allergens. The levels of specific IgE, total IgE, and tryptase were compared between patients with large local reactions and systemic reactions, and the relation of these parameters with the severity of systemic reaction was evaluated. Results: There were no significant differences in the specific IgE, total IgE, and tryptase values in patients with large local reactions and a history of systemic reactions (p > 0.05). The age, basal tryptase, and V. vulgaris-specific IgE levels of patients with a grade IV reaction history were higher than those with grades I-III reaction history (p < 0.05). An important finding was that high basal tryptase levels were a risk factor for grade IV reactions (p = 0.047, χ² = 4.512). There was a strong positive correlation between total IgE levels and V. vulgaris- and A. mellifera-specific IgE values in patients with a grade IV reaction history (r = 0.94, p = 0.005; and r = 0.88, p = 0.021, respectively). Conclusion: Baseline serum tryptase levels were a risk factor for the development of severe systemic reactions in venom allergy. This risk increases with increasing age in these patients. Another notable finding was the correlation between total IgE and venom-specific IgE values in patients with severe systemic reactions.
Assuntos
Venenos de Artrópodes/imunologia , Himenópteros/patogenicidade , Hipersensibilidade/etiologia , Fatores Etários , Alérgenos/efeitos adversos , Animais , Feminino , Humanos , Hipersensibilidade/patologia , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Masculino , Fatores de Risco , Testes Cutâneos , Triptases/sangueRESUMO
Chelonus insularis (Hymenoptera: Braconidae) is an egg-larval endoparasitoid that attacks several lepidopteran species, including the fall armyworm (FAW), Spodoptera frugiperda, as one of its main hosts. In this study, we identified the volatiles emitted by maize plants undamaged and damaged by S. frugiperda larvae that were attractive to virgin C. insularis females. In a Y-glass tube olfactometer, parasitoid females were more attracted to activated charcoal extracts than Porapak Q maize extracts. Chemical analysis of activated charcoal extracts from maize plants damaged by S. frugiperda larvae by gas chromatography coupled with electroantennography (GC-EAD) showed that the antennae of virgin female wasps consistently responded to three compounds, identified by gas chromatography-mass spectrometry (GC-MS) as α-pinene, α-longipinene and α-copaene. These compounds are constitutively released by maize plants but induction via herbivory affects their emissions. α-Longipinene and α-copaene were more abundant in damaged maize plants than in healthy ones, whereas α-pinene was produced in higher amounts in healthy maize plants than in damaged ones. Female parasitoids were not attracted to EAD-active compounds when evaluated singly; however, they were attracted to the binary blend α-pinene + α-copaene, which was the most attractive blend, even more attractive than the tertiary blend (α-pinene + α-longipinene + α-copaene) and the damaged maize plant extracts. We conclude that C. insularis is attracted to a blend of herbivore-induced volatiles emitted by maize plants.
Assuntos
Herbivoria , Himenópteros/patogenicidade , Spodoptera/parasitologia , Compostos Orgânicos Voláteis/metabolismo , Zea mays/metabolismo , Animais , Feminino , Cromatografia Gasosa-Espectrometria de MassasRESUMO
The wheat stem sawfly (WSS), Cephus cinctus Norton (Hymenoptera: Cephidae), is an important pest of wheat and other cereals, threatening the quality and quantity of grain production. WSS larvae feed and develop inside the stem where they are protected from the external environment; therefore, pest management strategies primarily rely on host plant resistance. A major locus on the long arm of wheat chromosome 3B underlies most of the variation in stem solidness; however, the impact of stem solidness on WSS feeding has not been completely characterized. Here, we used a multiomics approach to examine the response to WSS in both solid- and semi-solid-stemmed wheat varieties. The combined transcriptomic, proteomic, and metabolomic data revealed that two important molecular pathways, phenylpropanoid and phosphate pentose, are involved in plant defense against WSS. We also detected a general downregulation of several key defense transcripts, including those encoding secondary metabolites such as DIMBOA, tricetin, and lignin, which suggested that the WSS larva might interfere with plant defense. We comparatively analyzed the stem solidness genomic region known to be associated with WSS tolerance in wild emmer, durum, and bread wheats, and described syntenic regions in the close relatives barley, Brachypodium, and rice. Additionally, microRNAs identified from the same genomic region revealed potential regulatory pathways associated with the WSS response. We propose a model outlining the molecular responses of the WSS-wheat interactions. These findings provide insight into the link between stem solidness and WSS feeding at the molecular level.
Assuntos
Brachypodium/genética , Himenópteros/patogenicidade , Oryza/genética , Imunidade Vegetal/genética , Caules de Planta/genética , Sintenia , Triticum/genética , Animais , Brachypodium/parasitologia , Cromossomos de Plantas/genética , Metaboloma , Oryza/parasitologia , Caules de Planta/metabolismo , Proteoma/genética , Proteoma/metabolismo , Transcriptoma , Triticum/parasitologiaRESUMO
Cabbage looper, Trichoplusia ni (Hübner) is an important lepidopteran pest on many vegetable and greenhouse crops, and some field crops. Although there are no commercial transgenic Bt vegetable or greenhouse crops, T. ni is a target of Bollgard II cotton, which produces Cry1Ac and Cry2Ab. We expand on previous work that examined the effect of Bt crops on parasitoids using Bt-resistant lepidopteran populations as hosts. Cry1Ac/Cry2Ab-resistant T. ni larvae were used to eliminate host quality effects and to evaluate the direct effects of Bt cotton on the parasitoids Copidosoma floridanum (Ashmead) and Cotesia marginiventris (Cresson). These tri-trophic studies confirm that Bt cotton had no significant impact on development, success of parasitism, survival and adult longevity of C. marginiventris when using Bt-resistant T. ni fed on Bt cotton. Similarly, this Bt cotton had no significant impact on the development, mummy weight and the number of progeny produced by C. floridanum. Our studies verified that lyophilized Bt crop tissue maintained its insecticidal bioactivity when incorporated into an artificial diet, demonstrating that hosts and parasitoids were exposed to active Cry proteins. The egg-larval parasitoid C. floridanum, or similar species that consume their entire host, should be considered useful surrogates in risk assessment of Bt crops to non-target arthropods.
Assuntos
Proteínas de Bactérias/genética , Endotoxinas/genética , Gossypium/parasitologia , Proteínas Hemolisinas/genética , Himenópteros/patogenicidade , Animais , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/metabolismo , Resistência à Doença , Endotoxinas/metabolismo , Gossypium/genética , Proteínas Hemolisinas/metabolismo , Interações Hospedeiro-Parasita , TransgenesRESUMO
In Brazil, the species Diatraea flavipennella and D. saccharalis play an important role in the sugar and alcohol agribusiness by causing many damages in sugarcane fields. The egg, larva, pupa, and adult stages are very morphologically similar between these species, and the identification can be confused. The internal transcribed spacer 2 (ITS 2) from ribosomal DNA has important features as evolutionary divergence. It is a good marker for species identification, participates in the rDNA processing, and has been applied in phylogenetic and population studies. This study aimed to make available a molecular marker to assist on the identification method of pests' species of Diatraea and to identify possible traces of Cotesia in the resistant host. The DNA was extracted from the egg, larva, and adult samples. PCR amplicons were purified and sequenced. The sequences were analyzed in MEGA 5.01. The ITS 2 length was 410 bp in D. flavipennella and 448 bp in D. saccharalis. The GC content was similar between the species. Three microsatellite loci were present in D. saccharalis and absent in D. flavipennella, contributing to differences in ITS 2 length in the species. An additional 367-bp band was attributed to Cotesia spp. The differences among ITS 2 from D. flavipennella, D. saccharalis, and Cotesia sp were sufficient to identify them on electrophoresis gel and sequencing. The presence of Cotesia sp traits in adult D. flavipennella showed possible host refractoriness, but further studies are necessary.
Assuntos
Código de Barras de DNA Taxonômico/métodos , DNA Espaçador Ribossômico , Himenópteros/genética , Lepidópteros/genética , Animais , Genoma de Inseto , Himenópteros/patogenicidade , Lepidópteros/crescimento & desenvolvimento , Lepidópteros/parasitologia , Repetições de MicrossatélitesRESUMO
Venoms secreted by the venom gland (VG) of parasitoid wasp help ensure successful parasitism by host immune suppression and developmental regulation. Cotesia vestalis, a larval endoparasitoid, and Diadromus collaris, a pupal endoparasitoid, parasitize the diamondback moth (DBM), Plutella xylostella. To explore and compare the venom components of two endoparasitoids, we sequenced transcriptomes of the VGs and wasp bodies without VGs (BWVGs) of the two endoparasitoids. Statistically enriched GO terms and KEGG pathways of the two VGs compared to respective whole-body background were similar and reflected active protein biosynthesis activities in the two VGs. 1,595 VG specific genes of the D. collaris VG and 1,461 VG specific genes of the C. vestalis VG were identified by comparative transcript profiling. A total of 444 and 513 genes encoding potential secretory proteins were identified and defined as putative venom genes in D. collaris VG and C. vestalis VG, respectively. The putative venom genes of the two wasps showed no significant similarity or convergence. More venom genes were predicted in D. collaris VG than C. vestalis VG, especially hydrolase-coding genes. Differences in the types and quantities of putative venom genes shed light on different venom functions.