Influence of total and specific IgE, serum tryptase, and age on severity of allergic reactions to Hymenoptera stings

The aim of this study was to analyze the influence of total serum IgE and other potential risk factors on severity of systemic allergic Hymenoptera sting reactions.

Antennal courtship and functional morphology of tyloids in the parasitoid wasp Syrphoctonus tarsatorius (Hymenoptera: Ichneumonidae: Diplazontinae)

Courtship behaviour and associated morphological characters are believed to evolve under diversifying sexual selection. In Hymenoptera, sexually dimorphic antennal structures, the 'tyloids', show a large variability. Although crucial for functional interpretation, the link between tyloid morphology and courtship behaviour has gained only limited attention. Here, we investigate antennal morphology and antennal courtship in the parasitoid wasp Syrphoctonus tarsatorius (Hymenoptera: Ichneumonidae: Diplazontinae). We confirm the glandular nature of the tyloids by light and scanning electron microscopy. Moreover, we report a new form of antennation during courtship, antennal double-coiling, which links morphology and behaviour by bringing the tyloids in direct contact with the antennae of the female, thus probably facilitating the transfer of a contact pheromone. We show that a change in haemolymph pressure is the activator of the antennal movement and that it can be reproduced in the laboratory using amputated antennae. Investigations of antennal structure and movement in three additional hymenopteran species suggest that the number and location of tyloids coincide with the modality of antennal coiling. Our method for simulating antennal movement will enable retrieving information about courtship behaviour from museum specimens, thus leading to a better understanding of the evolution of courtship behaviour in Hymenoptera.

The evolution of antennal courtship in diplazontine parasitoid wasps (Hymenoptera, Ichneumonidae, Diplazontinae)

Background As predicted by theory, traits associated with reproduction often evolve at a comparatively high speed. This is especially the case for courtship behaviour which plays a central role in reproductive isolation. On the other hand, courtship behavioural traits often involve morphological and behavioural adaptations in both sexes; this suggests that their evolution might be under severe constraints, for instance irreversibility of character loss. Here, we use a recently proposed method to retrieve data on a peculiar courtship behavioural trait, i.e. antennal coiling, for 56 species of diplazontine parasitoid wasps. On the basis of a well-resolved phylogeny, we reconstruct the evolutionary history of antennal coiling and associated morphological modifications to study the mode of evolution of this complex character system. Results Our study reveals a large variation in shape, location and ultra-structure of male-specific modifications on the antennae. As for antennal coiling, we find either single-coiling, double-coiling or the absence of coiling; each state is present in multiple genera. Using a model comparison approach, we show that the possession of antennal modifications is highly correlated with antennal coiling behaviour. Ancestral state reconstruction shows that both antennal modifications and antennal coiling are highly congruent with the molecular phylogeny, implying low levels of homoplasy and a comparatively low speed of evolution. Antennal coiling is lost on two independent occasions, and never reacquired. A zero rate of regaining antennal coiling is supported by maximum parsimony, maximum likelihood and Bayesian approaches. Conclusions Our study provides the first comparative evidence for a tight correlation between male-specific antennal modifications and the use of the antennae during courtship. Antennal coiling in Diplazontinae evolved at a comparatively low rate, and was never reacquired in any of the studied taxa. This suggests that the loss of antennal coiling is irreversible on the timescale examined here, and therefore that evolutionary constraints have greatly influenced the evolution of antennal courtship in this group of parasitoid wasps. Further studies are needed to ascertain whether the loss of antennal coiling is irreversible on larger timescales, and whether evolutionary constraints have influenced courtship behavioural traits in a similar way in other groups.

An increase in serum tryptase even below 11.4 ng/mL may indicate a mast cell-mediated hypersensitivity reaction: a prospective study in Hymenoptera venom allergic patients

During a systemic hypersensitivity reaction (SR), an increase in serum tryptase compared to the baseline value is an indicator of mast cell activation, most often due to an IgE-mediated mechanism.

The evolution of host associations in the parasitic wasp genus Ichneumon (Hymenoptera: Ichneumonidae): convergent adaptations to host pupation sites

Background: The diversification of organisms with a parasitic lifestyle is often tightly linked to the evolution of their host associations. If a tight host association exists, closely related species tend to attack closely related hosts; host associations are less stable if associations are determined by more plastic traits like parasitoid searching and oviposition behaviour. The pupal-parasitoids of the genus Ichneumon attack a variety of macrolepidopteran hosts.They are either monophagous or polyphagous, and therefore offer a promissing system to investigate the evolution of host associations. Ichneumon was previously divided into two groups based on general body shape; however, a stout shape has been suggested as an adaptation to buried host pupation sites, and might thus not represent a reliable phylogenetic character. Results: We here reconstruct the first molecular phylogeny of the genus Ichneumon using two mitochondrial (CO1 and NADH1) and one nuclear marker (28S). The resulting phylogeny only supports monophyly of Ichneumon when Ichneumon lugens Gravenhorst, 1829 (formerly in Chasmias, stat. rev.) and Ichneumon deliratorius Linnaeus, 1758 (formerly Coelichneumon) are included. Neither parasitoid species that attack hosts belonging to one family nor those attacking butterflies (Rhopalocera) form monophyletic clades. Ancestral state reconstructions suggest multiple transitions between searching for hosts above versus below ground and between a stout versus elongated body shape. A model assuming correlated evolution between the two characters was preferred over independent evolution of host-searching niche and body shape. Conclusions: Host relations, both in terms of phylogeny and ecology, evolved at a high pace in the genus Ichneumon. Numerous switches between hosts of different lepidopteran families have occurred, a pattern that seems to be the rule among idiobiont parasitoids. A stout body and antennal shape in the parasitoid female is confirmed as an ecological adaptation to host pupation sites below ground and has evolved convergently several times. Morphological characters that might be involved in adaptation to hosts should be avoided as diagnostic characters for phylogeny and classification, as they can be expected to show high levels of homoplasy.

Hymenoptera aculeata der Provinzen West- und Ostpreussen

Neu bearbeitet von C. G. A. Brischke

Variaciones numéricas de Diaphorina citri Kuwayama (Sternorrhyncha: Psyllidae) y del Ectoparasitoide Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) en una plantación de naranjos de Entre Ríos, Argentina

Diaphorina citri es vector de la bacteria que produce la enfermedad HLB en cítricos, una de las más destructivas. En lotes comerciales de naranja dulce en Entre Ríos se analizó la abundancia espacio-temporal de adultos de D. citri y del ectoparasitoide Tamarixia radiata. Quincenalmente y durante tres años se colectaron adultos en 10 trampas cromotrópicas y los datos obtenidos fueron relacionados con el porcentaje medio de brotación de otra plantación. El número de D. citri/trampa/quincena se analizó mediante Kruskal-wallis y prueba de Mantel y la respuesta de agregación de T. radiata mediante correlación. Ambas poblaciones exhibieron la mayor abundancia el primer año: las frecuentes aplicaciones de abamectina en el segundo y tercero provocaron una marcada reducción. Espacialmente, la diferencia numérica de D. citri entre árboles no estuvo asociada a su cercanía pero la correlación entre ellos fue significativa. Temporalmente se evidenciaron cuatro picos de abundancia: tres asociados a brotación (invernal, primaveral y estival), y un cuarto no asociado a brotación. La mayor abundancia de T. radiata ocurrió en los árboles con mayor abundancia de D. citri y hubo una significativa correlación espacial entre ambas especies. El enrollamiento anti-horario del gráfico entre D. citri - T. radiata en árboles individuales sugiere una interacción huésped- parasitoide, estructurada como poblaciones locales.

Evaluación de los efectos de la composición de la dieta artificial para la cría de Diatraea saccharalis (Lepidoptera: Crambidae) y Cotesia flavipes (Hymenoptera: Braconidae)

El control biológico aumentativo de Diatrae saccharalis Fabricius (Lepidoptera: Crambidae) requiere la cría masiva del parasitoide Cotesia flavipes Cameron (Braconidae: Microgastrinae) y por ello, es necesario el desarrollo de dietas artificiales eficientes. El objetivo fue examinar los efectos de distintos tipos de dieta sobre parámetros biológicos de D. saccharalis y su impacto en la producción de cocones de C. flavipes. Se sembraron 46136 huevos de D. saccharalis en once combinaciones de dietas artificiales, con dos tipos de harinas y tres tipos de antibióticos. Los resultados mostraron que la composición de la dieta afectó los parámetros biológicos de ambas especies. La mayor eficiencia en la cría se obtuvo con el empleo de combinaciones de harina de poroto y ampicilina. Sin embargo, si se considera la relación entre costos de producción y parámetros biológicos, la dieta con harina de poroto, oxitetraciclina y estreptomicina resulta más adecuada para la cría masiva.

Ecotoxicity of insecticides of frequent use in tomatoes on Trichogramma achaeae (Hymenoptera: Trichogrammatidae)

Since Tuta absoluta(Meyrick) (Lepidoptera: Gelechiidae) was detected in 2006 as a new pest in tomato crops in Spain, several natural enemies have been reported tocontrol this pest. In biological control programs, the native parasitoid Trichogramma achaeae Nagaraja&Nagarkatti (Hymenoptera: Trichogrammatidae) is used against T.absoluta. However, the most common control practice is based on use of pesticides,and in the frame of Integrated Pest Management (IPM) programs, the knowledge on the activity of insecticides towards beneficial insects is needed for its joint use. In thiswork, we evaluated lethal and sublethal effects of insecticides commonly applied on tomato crops on adults of T. achaeae. Pesticides were sprayed on tomato plants or T. Absoluta eggs till run off at their maximum field recommended concentration. Mortality was scored after 24, 48 and 72 hours, as well as beneficial capacity and percentage of emergence.

Compatibilidad de Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) y Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae), importantes enemigos naturales de la mosca blanca Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) en cultivos hortícolas, con nuevas barreras físicas selectivas y modernos plaguicidas

Los programas de Gestión Integrada de Plagas (GIP) promueven el uso de estrategias de control que sean respetuosas con el medio ambiente, sin embargo el uso de insecticidas en los cultivos hortícolas sigue siendo necesario para el control de determinadas plagas, como es el caso de la mosca blanca Bemisia tabaci (Gennadius). Por ello, el objetivo de esta tesis es el estudio de la integración de las tres estrategias de control más empleadas hoy en día para el control de plagas: el control biológico, el físico y el químico. Una primera parte de este trabajo ha consistido en el estudio de los efectos letales y subletales de once insecticidas, aplicados a la dosis máxima de campo, sobre los enemigos naturales Eretmocerus mundus Mercet y Amblyseius swirskii Athias-Henriot, mediante ensayos de laboratorio y persistencia (laboratorio extendido). Para la evaluación de la toxicidad de los insecticidas sobre los estados de vida más protegidos de estos enemigos naturales, se trataron bajo la Torre de Potter las pupas de E. mundus y los huevos de A. swirskii. Además, se llevaron a cabo ensayos de contacto residual para determinar los efectos letales y subletales de estos insecticidas sobre el estado adulto de ambas especies de enemigos naturales. Para ello, los pesticidas se aplicaron sobre placas de cristal (laboratorio) o sobre plantas (laboratorio extendido: persistencia). Los resultados mostraron que los insecticidas flonicamida, flubendiamida, metaflumizona, metoxifenocida, spiromesifen y spirotetramat eran compatibles con el estado de pupa de E. mundus (OILB 1: Inocuos). Sin embargo, abamectina, deltametrina y emamectina fueron categorizadas como ligeramente tóxicas (OILB 2) al causar efectos deletéreos. Los dos pesticidas más tóxicos fueron spinosad y sulfoxaflor, los cuales redujeron significativamente la emergencia de las pupas tratadas (OILB 4: Tóxicos). Flonicamida, flubendiamida, metoxifenocida y spiromesifen fueron compatibles con el estado adulto de E. mundus (OILB 1: Inocuos). Abamectina, deltametrina, emamectina, metaflumizona y spiromesifen pueden ser recomendados para su uso en programas de GIP, si se usan los plazos de seguridad apropiados, de acuerdo con la persistencia de cada uno de estos insecticidas, antes de la liberación del enemigo natural. Al contrario, spinosad y sulfoxaflor no resultaron ser compatibles (OILB D: Persistentes), aunque la realización de ensayos adicionales es necesaria para ver los efectos de los mismos en campo. Todos los insecticidas estudiados, excepto el spirotetramat (OILB 2: Ligeramente tóxico), fueron selectivos para el estado de huevo de A. swirskii (OILB 1: Inocuos). Flonicamida, flubendiamida, metaflumizona, metoxifenocida, spiromesifen, spirotetramat y sulfoxaflor, fueron compatibles con el estado adulto de A. swirskii (OILB 1: Inocuos). Abamectina, deltametrina, emamectina y spinosad pueden ser recomendados para su uso en programas de GIP, si se usan los plazos de seguridad apropiados, de acuerdo con la persistencia de cada uno de estos insecticidas, antes de la liberación del enemigo natural. Entre las nuevas estrategias de la GIP, los plásticos y mallas fotoselectivas han demostrado ser una herramienta importante para el control de plagas y enfermedades en cultivos hortícolas protegidos. Por ello, en una segunda parte de este trabajo, se estudiaron tanto los efectos directos, como la combinación de efectos directos y mediados por planta y plaga de ambientes pobres en luz UV, en presencia o ausencia del Virus del rizado amarillo del tomate (TYLCV), sobre E. mundus. En primer lugar, se realizó un ensayo al aire libre para la evaluación de la capacidad de vuelo de E. mundus en cajas tipo túnel (1 x 0,6 x 0,6 m) cubiertas con distintas barreras absorbentes de luz UV. Se detectó un efecto directo en la capacidad de orientación de E. mundus, debido a que este parasitoide utiliza estímulos visuales para localizar a sus huéspedes, únicamente en las barreras que bloqueaban más del 65% de la luz UV (malla G). En segundo lugar, bajo condiciones de invernadero, se evaluó la combinación de efectos directos y mediados por planta y plaga sobre E. mundus, usando plantas de tomate sanas o infectadas con el TYLCV y cajas (30 x 30 x 60 cm) cubiertas con los distintos plásticos fotoselectivos. En este caso, no se observó ningún efecto en la capacidad benéfica del parasitoide cuando este estaba en contacto con plantas de tomate infestadas con ninfas de B. tabaci, lo que demuestra que este insecto usa estímulos táctiles para encontrar a sus huéspedes a cortas distancias. Además, las diferentes condiciones de radiación UV estudiadas tuvieron cierto impacto en la morfología, fisiología y bioquímica de las plantas de tomate, infestadas o no con el virus de la cuchara, detectándose pequeñas alteraciones en alguno de los parámetros estudiados, como el peso fresco y seco, el contenido en H y el espesor de las cutículas y de las paredes celulares de la epidermis foliar. Por último, no se observaron efectos de la radiación UV mediados por planta, ni en B. tabaci ni en su parasitoide, E. mundus. En una tercera parte, se evaluaron los efectos de una malla tratada con bifentrin sobre ambos enemigos naturales, en ensayos de laboratorio, semicampo y campo. Las mallas tratadas fueron diseñadas originariamente para el control de mosquitos vectores de la malaria, y actualmente se está trabajando para su uso en agricultura, como una nueva estrategia de control de plagas. En ensayos de laboratorio, cuando adultos de E. mundus y A. swirskii se expusieron por contacto durante 72 horas con la malla tratada (cajas de 6 cm diámetro), se registró una alta mortalidad. Sin embargo, en el ensayo de preferencia, estos enemigos naturales no fueron capaces de detectar la presencia de bifentrin y, en aquellos individuos forzados a atravesar la malla tratada, no se observó mortalidad a corto plazo (72 horas). En estudios de semicampo, llevados a cabo bajo condiciones de invernadero en cajas de 25 x 25 x 60 cm de altura, la capacidad benéfica de E. mundus no se vio afectada. Finalmente, en ensayos de campo llevados a cabo en invernaderos comerciales (4000m2) en Almería, A. swirskii no se vio afectado por la presencia en el cultivo de la malla tratada con bifentrin y los niveles de infestación de B. tabaci y F. occidentalis detectados bajo dicha malla, fueron inferiores a los del control. Por último, se ha evaluado la composición de la microflora bacteriana de tres especies de parasitoides, E. mundus, Eretmocerus eremicus Rose & Zolnerowich y Encarsia formosa Gahan, y la influencia de la misma en su susceptibilidad a insecticidas. Se llevó a cabo una extracción total de ADN de los insectos y la región variable V4 del ARNr se amplificó usando cebadores universales bacterianos. Para identificar las secuencias de los géneros bacterianos presentes en los parasitoides, se realizó una Next Generation sequencing (Illumina sequencing). Una vez identificados los géneros bacterianos, el gen ADNr 16S de las Actinobacterias se amplificó del ADN extraído de los insectos, usando cebadores universales bacterianos y específicos de Actinobacterias, y los productos de la Nested PCR fueron clonados para identificar todas las especies del género Arthrobacter. Tres bacterias (A. aurescens Phillips, A. nicotinovarans Kodama, Yamamoto, Amano and Amichi y A. uratoxydans Stackebrandt, Fowler, Fiedler and Seiler), próximas a las especies de Arthrobacter presentes en los parasitoides, se obtuvieron de la colección bacteriana del BCCMTM/LMG y se midió su actividad esterasa. Finalmente, se realizaron ensayos con antibióticos (tetraciclina) y de contacto residual con insecticidas (abamectina) para determinar la influencia de las especies de Arthrobacter en la susceptibilidad de E. mundus a insecticidas. Los resultados muestran que este género bacteriano puede afectar a la toxicidad de E. mundus a abamectina, mostrando la importancia de la comunidad microbiana en enemigos naturales, factor que debe ser considerado en los estudios de evaluación de los riesgos de los insecticidas. ABSTRACT Integrated Pest Management (IPM) programs promote the use of control strategies more respectful with the environment; however the use of insecticides in vegetable crops is still needed to control certain pests, such as the whitefly Bemisia tabaci (Gennadius). Therefore, the objective of this work is to study the integration of the three most commonly used pest control strategies nowadays: biological, physical and chemical control. Firstly, the lethal and sublethal effects of eleven insecticides, applied at their maximum field recommended concentration, on the parasitic wasp Eretmocerus mundus Mercet and the predator Amblyseius swirskii Athias-Henriot has been assessed in the laboratory and in persistence tests (extended laboratory). To test the effects of pesticides on the most protected life stage of these natural enemies, E. mundus pupae and A. swirskii eggs were sprayed under a Potter precision spray tower. Laboratory contact tests were therefore conducted to determine the lethal and sublethal effects of these pesticides on the adult stage of these natural enemies. In the residual contact tests the pesticides were applied on glass plates (laboratory) or plants (extended laboratory: persistence). The study showed that the insecticides flonicamid, flubendiamide, metaflumizone, methoxyfenozide, spiromesifen and spirotetramat were selective for E. mundus pupae (IOBC 1: Harmless). Nevertheless, abamectin, deltamethrin and emamectin were categorized as slightly harmful (IOBC 2) due to the deleterious effects caused. The two most harmful pesticides were spinosad and sulfoxaflor, which significantly reduced the adult emergence from treated pupae (IOBC 4: Harmful). Flonicamid, flubendiamide, methoxyfenozide and spiromesifen were compatible with E. mundus adults (IOBC 1: Harmless). Base on the duration of the harmful activity, abamectin, deltamethrin, emamectin, metaflumizone and spirotetramat could be recommended for use in IPM programs if appropriate safety deadlines are used before the natural enemy release. On the contrary, spinosad and sulfoxaflor were not compatible (IOBC D: persistent), although additional studies are required to determine their effects under field conditions. All the pesticides tested, except spirotetramat (IOBC 2: Slightly harmful), were selective for A. swirskii eggs (IOBC 1: Harmless). Flonicamid, flubendiamide, metaflumizone, methoxyfenozide, spiromesifen, spirotetramat and sulfoxaflor were compatible with A. swirskii adults (IOBC 1: Harmless). However, abamectin, deltamethrin, emamectin and spinosad could be recommended for use in IPM programs if appropriate safety deadlines are used before the natural enemy release. Among new IPM strategies, UV-absorbing photoselective plastic films and nets have been shown to be an important tool for the control of pests and diseases in horticultural protected crops. Because of that, we secondly studied the plant and pest insect-mediated and/or the direct effects on E. mundus under different UV radiation conditions, in presence or absence of the Tomato Yellow Leaf Curl Virus (TYLCV). In the first experiment, performed outdoors, the flight activity of E. mundus was studied in one-chamber tunnels (1 x 0.6 x 0.6 m) covered with different photoselective barriers. Because E. mundus uses visual cues for host location at a long distance, a direct effect on its host location ability was detected, but only in the UV-absorbing barriers blocking more than 65% of the UV light (G net). In a second experiment, the direct and plant and pest insect-mediated effects of different UV radiation conditions on E. mundus were studied, inside cages (30 x 30 x 60 cm) covered with the different UVplastic films and under greenhouse conditions, using healthy or TYLCV-virus infected tomato plants. In this case, not any effect on the beneficial capacity of this parasitoid was detected, proving that he uses tactile cues at a short distance of the host. Moreover, the different UV radiation conditions studied had a certain direct impact in the morphology, physiology and biochemistry of tomato plants infested or not with the TYLCV, and small alterations in some parameters such as fresh and dry weight, H percentage and cuticle and cell wall thickness of epidermal cells of the leaves, were detected. Finally, none plant-mediated UV effects neither in the whitefly B. tabaci nor in their parasitic wasp were found. Thirdly, the effects of a bifenthrin treated net were evaluated in different laboratory, semi-field and field experiments on the natural enemies studied. Treated nets were developed long time ago aiming at the control of the mosquitoes vectors of malaria, and nowadays, there is a great interest on assessing the possibility of their use in agriculture. In laboratory assays, a high mortality was recorded when E. mundus and A. swirskii adults were exposed by contact to the bifenthrin treated net for 72 hours in small cages (12 cm diameter). However, these natural enemies were not able to detect the presence of bifenthrin in a dual-choice test and no short-term mortality (72 hours) was recorded in those individuals that went through the treated net. In semi-field assays, performed under greenhouse conditions with cages of 25 x 25 x 60 cm high, the beneficial capacity of E. mundus was not affected. Finally, in field assays carried out in commercial multispan greenhouses (4000 m2) in Almería, A. swirskii was not affected by the presence of the bifenthrin treated net in the crop and the B. tabaci and F. occidentalis infestation levels were significantly lower than in the control. Finally, the composition of the microflora present in three species of parasitoids, E. mundus, Eretmocerus eremicus Rose & Zolnerowich and Encarsia formosa Gahan, and its influence in their susceptibility to insecticides, have been assessed. A total DNA extraction was performed on insects and universal bacterial primers were used to amplify the variable V4 region of the rRNA. A Next Generation sequencing (Illumina sequencing) was performed to identify the sequences of the bacterial genera present in the parasitic wasps. Once, the bacterial genera were identified, 16S rDNA gene of Actinobacteria were amplified from insects DNA extracts using the universal bacterial and actinobacterial primers, and the nested PCR products, were cloned to identify the Arthrobacter species. Three bacteria (A. aurescens Phillips, A. nicotinovarans Kodama, Yamamoto, Amano and Amichi and A. uratoxydans Stackebrandt, Fowler, Fiedler and Seiler), having the closest match with the Arthrobacter species present in the parasitic wasps, were obtained from the BCCMTM/LMG bacteria collection and its esterase activity was measured. Finally, antibiotic and residual contact tests were done to determine the influence of Arthrobacter species in the susceptibility of E. mundus to pesticides (abamectin). The results suggest that this bacterial genus can affect the toxicity of E. mundus to abamectin, which in turn supports the importance of the microbial community in natural enemies that it should be considered as a factor in risk assessment tests of pesticides.