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1.
J Insect Sci ; 21(2)2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33861348

RESUMO

The potential of the parasitoid Psyllaephagus bliteus Riek for the biological control of the eucalyptus pest Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae) nymphs is high. This research sought to analyze the courtship, male competition, and mating behavior of P. bliteus at the proportions of 1:1 and 2:1 males to female in a Petri dish (5 cm diameter), and to describe the ovary histology of virgin and mated females of this parasitoid. At 1:1, males touch the antennae and thorax-abdomen of females during courtship, but females avoid mate attempts before they are 48 h old. At 2:1, the competition between male parasitoids inhibits mating. The histology of ovaries of virgin and mated P. bliteus females is similar, with two well-defined germarium and vitellarium regions, with oocytes at different developmental stages, including mature ones rich in yolk and with eggshell. A clearer understanding of the reproductive behavior and histology of P. bliteus aids in the use of this parasitoid for the biological control of G. brimblecombei.


Assuntos
Himenópteros/anatomia & histologia , Himenópteros/fisiologia , Comportamento Sexual Animal , Animais , Corte , Feminino , Hemípteros/crescimento & desenvolvimento , Hemípteros/parasitologia , Interações Hospedeiro-Parasita , Controle de Insetos , Masculino , Ninfa/parasitologia , Ovário/anatomia & histologia , Controle Biológico de Vetores
2.
Bull Entomol Res ; 111(3): 348-356, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33345769

RESUMO

Parasitoids can be used as biological agents of pest control. Anagyrus saccharicola Timberlake (Hymenoptera: Encyrtidae) is a parasitoid of the pink sugarcane mealybug Saccharicoccus sacchari (Cockerell) (Hemiptera: Pseudococcidae). Although this mealybug is present in all sugarcane-producing countries, there is limited information regarding this pest and its parasitoid. Aiming to elucidate information on bioecological parameters of A. saccharicola, were evaluated the survival of parasitoid females and males at three temperatures, the host preference of the parasitoid, and the fecundity and longevity of the host. In addition, the parasitism rate of A. saccharicola was estimated based on three factors, feeding, mating, and time. Survival was evaluated at 20, 25, and 30°C. Host preference was conducted on 15-, 20-, and 30-day-old mealybugs. And the parasitism rate was evaluated in fed and unfed, mated and unmated parasitoids and with 24 h and newly emerged. The temperature of 20°C was the most favorable for parasitoid survival. Parasitism occurred at all evaluated ages of the mealybug; however, the preference was for those that were 30-days-old. The parasitized mealybugs longevity was approximately 8 additional days after parasitization, and non-parasitized mealybugs lived for an additional 20 days for mealybugs aged 30 and 20 days at the outset of the tests, and a further 13 days for the 15 days. Feeding and mating after 24 h of emergence resulted in a higher parasitism rate. These findings can contribute to more efficient rearing of A. saccharicola and in the planning of the biological control of S. sacchari in the integrated pest management programs.


Assuntos
Hemípteros/parasitologia , Controle Biológico de Vetores/métodos , Vespas/fisiologia , Animais , Produtos Agrícolas , Fertilidade/fisiologia , Interações Hospedeiro-Parasita , Longevidade/fisiologia , Parasitos/fisiologia , Saccharum , Razão de Masculinidade , Especificidade da Espécie , Temperatura
3.
PLoS Genet ; 16(12): e1009170, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33326438

RESUMO

Analysis of genetic polymorphism is a powerful tool for epidemiological surveillance and research. Powerful inference from pathogen genetic variation, however, is often restrained by limited access to representative target DNA, especially in the study of obligate parasitic species for which ex vivo culture is resource-intensive or bias-prone. Modern sequence capture methods enable pathogen genetic variation to be analyzed directly from host/vector material but are often too complex and expensive for resource-poor settings where infectious diseases prevail. This study proposes a simple, cost-effective 'genome-wide locus sequence typing' (GLST) tool based on massive parallel amplification of information hotspots throughout the target pathogen genome. The multiplexed polymerase chain reaction amplifies hundreds of different, user-defined genetic targets in a single reaction tube, and subsequent agarose gel-based clean-up and barcoding completes library preparation at under 4 USD per sample. Our study generates a flexible GLST primer panel design workflow for Trypanosoma cruzi, the parasitic agent of Chagas disease. We successfully apply our 203-target GLST panel to direct, culture-free metagenomic extracts from triatomine vectors containing a minimum of 3.69 pg/µl T. cruzi DNA and further elaborate on method performance by sequencing GLST libraries from T. cruzi reference clones representing discrete typing units (DTUs) TcI, TcIII, TcIV, TcV and TcVI. The 780 SNP sites we identify in the sample set repeatably distinguish parasites infecting sympatric vectors and detect correlations between genetic and geographic distances at regional (< 150 km) as well as continental scales. The markers also clearly separate TcI, TcIII, TcIV and TcV + TcVI and appear to distinguish multiclonal infections within TcI. We discuss the advantages, limitations and prospects of our method across a spectrum of epidemiological research.


Assuntos
Código de Barras de DNA Taxonômico/métodos , Genoma de Protozoário , Metagenoma , Metagenômica/métodos , Trypanosoma cruzi/genética , Sequenciamento Completo do Genoma/métodos , Animais , Custos e Análise de Custo , Código de Barras de DNA Taxonômico/economia , Código de Barras de DNA Taxonômico/normas , Vetores de Doenças , Hemípteros/parasitologia , Metagenômica/economia , Metagenômica/normas , Polimorfismo Genético , Trypanosoma cruzi/patogenicidade , Virulência/genética , Sequenciamento Completo do Genoma/economia , Sequenciamento Completo do Genoma/normas
4.
Acta Parasitol ; 65(1): 108-117, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31755068

RESUMO

BACKGROUND: Protozoa are distantly related to vertebrates but present some features of higher eukaryotes, making them good model systems for studying the evolution of basic processes such as the cell cycle. Herpetomonas samuelpessoai is a trypanosomatid parasite isolated from the hemipteran insect Zelus leucogrammus. Lysophosphatidylcholine (LPC) is implicated in the transmission and establishment of Chagas disease, whose etiological agent is Trypanosoma cruzi. LPC is synthesized by T. cruzi and its vectors, the hemipteran Rhodnius prolixus and Triatoma infestans. Platelet-activating factor (PAF), a phospholipid with potent and diverse physiological and pathophysiological actions, is a powerful inducer of cell differentiation in Herpetomonas muscarum muscarum and T. cruzi. The enzyme phospholipase A2 (PLA2) catalyzes the hydrolysis of the 2-ester bond of 3-sn-phosphoglyceride, transforming phosphatidylcholine (PC) into LPC. METHODS: In this study, we evaluated cellular differentiation, PLA2 activity and protein kinase CK2 activity of H. samuelpessoai in the absence and in the presence of LPC and PAF. RESULTS: We demonstrate that both PC and LPC promoted a twofold increase in the cellular differentiation of H. samuelpessoai, through CK2, with a concomitant inhibition of its cell growth. Intrinsic PLA2 most likely directs this process by converting PC into LPC. CONCLUSIONS: Our results suggest that the actions of LPC on H. samuelpessoai occur upon binding to a putative PAF receptor and that the protein kinase CK2 plays a major role in this process. Cartoon depicting a model for the synthesis and functions of LPC in Herpetomonas samuelpessoai, based upon our results regarding the role of LPC on the cell biology of Trypanosoma cruzi [28-32]. N nucleus, k kinetoplast, PC phosphatidylcholine, LPC lysophosphatidylcholine, PLA2 phospholipase A2, PAFR putative PAF receptor in trypanosomatids [65], CK2 protein kinase CK2 [16].


Assuntos
Caseína Quinase II/metabolismo , Diferenciação Celular , Lisofosfatidilcolinas/metabolismo , Redes e Vias Metabólicas , Trypanosomatina/fisiologia , Animais , Diclororribofuranosilbenzimidazol/farmacologia , Inibidores Enzimáticos/farmacologia , Hemípteros/parasitologia , Fosfolipases A2/metabolismo , Triazóis/farmacologia , Trypanosomatina/efeitos dos fármacos
5.
Insect Sci ; 27(4): 815-825, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31250982

RESUMO

As solitary nymphal parasitoids of Paratrioza sinica, the ectoparasitoid Tamarixia lyciumi and the endoparasitoid Psyllaephagus arenarius act as effective biocontrol agents. Thus, it is necessary to facilitate mass productions of both species. Despite showing an excellent parasitic ability, Ps. arenarius is often trapped fatally inside 5th-instar nymphs of Pa. sinica due to strong host immunity. To improve the emergence rate of Ps. arenarius, we evaluated whether Ps. arenarius could utilize T. lyciumi venom via multiparasitism, so the parasitism characteristics of both species were examined between separate-existence (monoparasitism only) and co-existence (mono- and multiparasitism) systems. Further, the parasitism characteristics of Ps. arenarius on venom-injected hosts with/without T. lyciumi eggs were tested to further identify the facilitator. The results showed the parasitism rate of T. lyciumi was increased while that of Ps. arenarius did not change from separate-existence to co-existence systems. The intrinsic performances of two species in monoparasitism did not differ between separate- and co-existence systems. From monoparasitism (separate-existence) to multiparasitism (co-existence), no differences were detected in the intrinsic performances of T. lyciumi, but those of Ps. arenarius were greatly improved. After T. lyciumi venom injection, the parasitism characteristics of Ps. arenarius did not differ between venom-injected hosts with T. lyciumi eggs and those without, further indicating Ps. arenarius benefited from the venom of T. lyciumi females rather than T. lyciumi egg/larval secretions. Instead of negative effects, multiparasitism with ectoparasitoids improves endoparasitoids due to ectoparasitic venom. The study increases host resource utilization and provides creative ways for mass production of endoparasitoids.


Assuntos
Hemípteros/parasitologia , Interações Hospedeiro-Parasita/fisiologia , Venenos de Vespas/metabolismo , Vespas/fisiologia , Animais , Feminino , Hemípteros/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Ninfa/crescimento & desenvolvimento , Ninfa/parasitologia , Vespas/crescimento & desenvolvimento
6.
Metabolomics ; 15(12): 151, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31741127

RESUMO

INTRODUCTION: Brown planthopper (BPH) is a phloem feeding insect that causes annual disease outbreaks, called hopper burn in many countries throughout Asia, resulting in severe damage to rice production. Currently, mechanistic understanding of BPH resistance in rice plant is limited, which has caused slow progression on developing effective rice varieties as well as effective farming practices against BPH infestation. OBJECTIVE: To reveal rice metabolic responses during 8 days of BPH attack, this study examined polar metabolome extracts of BPH-susceptible (KD) and its BPH-resistant isogenic line (IL308) rice leaves. METHODS: Ultra high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QToF-MS) was combined with multi-block PCA to analyze potential metabolites in response to BPH attack. RESULTS: This multivariate statistical model revealed different metabolic response patterns between the BPH-susceptible and BPH-resistant varieties during BPH infestation. The metabolite responses of the resistant IL308 variety occurred on Day 1, which was significantly earlier than those of the susceptible KD variety which showed an induced response by Days 4 and 8. BPH infestation caused metabolic perturbations in purine, phenylpropanoid, flavonoid, and terpenoid pathways. While found in both susceptible and resistant rice varieties, schaftoside (1.8 fold), iso-schaftoside (1.7 fold), rhoifolin (3.4 fold) and apigenin 6-C-α-L-arabinoside-8-C-ß-L-arabinoside levels (1.6 fold) were significantly increased in the resistant variety by Day 1 post-infestation. 20-hydroxyecdysone acetate (2.5 fold) and dicaffeoylquinic acid (4.7 fold) levels were considerably higher in the resistant rice variety than those in the susceptible variety, both before and after infestation, suggesting that these secondary metabolites play important roles in inducible and constitutive defenses against the BPH infestation. CONCLUSIONS: These potential secondary metabolites will be useful as metabolite markers and/or bioactive compounds for effective and durable approaches to address the BPH problem.


Assuntos
Oryza/química , Oryza/metabolismo , Metabolismo Secundário/fisiologia , Animais , Cromatografia Líquida de Alta Pressão/métodos , Resistência à Doença/genética , Didrogesterona/análogos & derivados , Didrogesterona/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Hemípteros/metabolismo , Hemípteros/parasitologia , Hemípteros/fisiologia , Metaboloma/genética , Oryza/genética , Fenótipo
7.
Cienc. tecnol. salud ; 6(2): 98-106, jul dic 2019. ^c27 cmilus
Artigo em Espanhol | LILACS | ID: biblio-1095831

RESUMO

El complejo de mosca blanca (Hemiptera: Aleyrodidae) incluye algunas de las principales plagas del ejote francés (Phaseolus vulgaris L.). Dentro de las cuales, Bemisia tabaci es vector del virus del mosaico dorado que afecta la calidad y rendimiento del cultivo, con pérdidas hasta del 100% y un control difícil debido a la resistencia adquirida por las plagas hacia algunos agroquímicos. El ejote francés ocupa el segundo lugar entre de los productos no tradicionales de exportación de Guatemala. Su manejo agronómico ha sido principalmente a través del control químico, el cual afecta insectos y otros organismos que no son el objetivo del control, tales como: polinizadores, insectos benéficos, humanos y fauna silvestre. Los objetivos del estudio fueron: determinar la presencia de enemigos naturales nativos de la mosca blanca e identificar las especies de mosca blanca presentes en el cultivo del ejote francés en Chimaltenango. Para el estudio se establecieron cuatro parcelas de 300 m², se realizaron muestreos semanales durante dos ciclos del cultivo. En cada parcela se muestrearon cinco sitios y en cada sitio cinco plantas. Las especies de parasitoides nativos encontrados fueron: Encarsia Formosa Gahan, Eretmocerus eremicus Rose y Zolnerowuch y Amitus fuscipennis MacGown y Nebeker, la especie más abundante fue A. fuscipennis. Los depredadores identificados fueron Chrysoperla carnea (Stephens) e Hippodamia convergens Guerin-Meneville. La especie más abundante fue H. convergens. Estas especies podrían ser herramientas valiosas para ser empleadas en programas de control biológico, producciones orgánicas o en programas de manejo integrado de plagas.


The whitefly complex (Hemiptera: Aleyrodidae) includes some of the main pests of the French green bean (Phaseolus vulgaris L.). Among which, Bemisia tabaci is a vector of the golden mosaic virus that affects the quality and yield of the crop, with losses up to 100% and difficult control due to the resistance acquired by pests towards some agrochemicals. The French green bean ranks second among the non-traditional export products of Guatemala. Its agronomic management has been mainly through chemical control, which affects insects and other organisms that are not the objective of the control, such as: pollinators, beneficial insects, humans and wildlife. The objectives of the study were: to determine the presence of natural enemies native to the whitefly and identify the species of whitefly present in the cultivation of the French bean in Chimaltenango. For the study, four 300 m² plots were established, weekly sampling was carried out during two crop cycles. Five sites were sampled on each plot and five plants on each site. The native parasitoid species found were: Encarsia Formosa Gahan, Eretmocerus eremicus Rose and Zolnerowuch and Amitus fuscipennis MacGown and Nebeker, the most abundant species was A. fuscipennis. The predators identified were Chrysoperla carnea (Stephens) and Hippodamia convergens Guerin-Meneville. The most abundant species was H. convergens. These species could be valuable tools to be used in biological control programs, organic productions or in integrated pest management programs.


Assuntos
Animais , Phaseolus/crescimento & desenvolvimento , Phaseolus/parasitologia , Hemípteros/crescimento & desenvolvimento , Hemípteros/parasitologia , Controle Biológico de Vetores/métodos , Vírus do Mosaico
8.
An Acad Bras Cienc ; 91(3): e20180597, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31618410

RESUMO

Several parasitoids attacking the same host may lead to competition. Adult parasitoids' abilities to find, parasitize and defend hosts determine resource's retention potential. In soybean, two egg parasitoid species, Telenomus podisi and Trissolcus urichi (Hymenoptera: Platygastridae), compete on the egg masses of Piezodorus guildinii (Hemiptera: Pentatomidae) one of the major pest of this crop. We evaluated parasitoid's abilities to exploit hosts' footprints; and parasitoid's behavior when competing for the same host. Both arena residence time and retention time were similar for T. podisi and T. urichi on male or female host footprints. In its turn, T. urichi reentered the area contaminated with P. guildinii more times and staid longer in it than T. podisi. Furthermore, when competing for the same egg mass, each parasitoid species won (was in possession of the host by the end of the experiment) half of the replicates, and the number of times each wasp species contacted host in the first place was similar, without affecting replicate outcome (who ultimately won). Both species started agonistic and non-agonistic encounters. This study provides information about the potential interspecific competition between these parasitoids, which contributes to evaluate the compatibility of multiple natural enemies' biological control programs for stink bugs.


Assuntos
Hemípteros/parasitologia , Controle Biológico de Vetores/métodos , Animais , Comportamento Animal/fisiologia , Feminino , Hemípteros/fisiologia , Interações Hospedeiro-Parasita , Masculino , Oviposição , Óvulo/fisiologia , Soja , Vespas/parasitologia
9.
Zoology (Jena) ; 135: 125689, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31383298

RESUMO

Heterorhabditis nematodes are parasites of a wide range of soil-dwelling insect species. Although these nematodes have been exploited as biological control agents since the last half of the 20th century, much research remains to be done to understand how these organisms function in agricultural and other ecosystems. In this study, we present some ecological traits of Heterorhabditis sonorensis, a natural parasite of the cicada Diceroprocta ornea, from the Sonoran Desert. Specifically, we evaluated its infectivity across a diverse panel of insect groups and assessed its fitness (infectivity and reproduction) considering different temperatures, and soil moisture levels. Three other Heterorhabditis species served as points of comparison for temperature and soil moisture assays. Host range experiments indicate that H. sonorensis, although isolated from seasonal cicada nymphs, is more virulent and reproductively fit in the lepidopteran hosts tested. This nematode has an optimum temperature range at 25-30 °C but can also successfully reproduce at temperatures ranging from 15 to 35 °C. Additionally, this nematode is adapted to a variety of soil moisture conditions with successful infections across the tested moisture range (3%-20%). Finally, we demonstrate that H. sonorensis infective juveniles have a high survival rate (over 80%) at various storage temperatures (10-25 °C) after 24 weeks of storage and remain infective as revealed by the post-storage infection assays.


Assuntos
Clima Desértico , Meio Ambiente , Nematoides , Animais , Hemípteros/parasitologia , Especificidade de Hospedeiro , Lepidópteros/parasitologia , Nematoides/fisiologia , Solo/química , Solo/parasitologia , Temperatura
10.
Sci Rep ; 9(1): 9440, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31263114

RESUMO

Citrus greening or huanglongbing (HLB) is the main threat to the European citrus industry since one of its vectors, the African citrus psyllid, Trioza erytreae, has recently become established in mainland Europe. In this context, classical biological control programmes should be implemented to reduce the spread of the psyllid. The aims of this study were to: i) disentangle the parasitoid complex of T. erytreae combining morphological and molecular characterization; and ii) to study the biology of its main parasitoids in its area of origin in South Africa for their future importation into Europe. The main citrus producing areas of South Africa were surveyed during 2017. In contrast to previous studies, the parasitoid complex of T. erytreae included three species of primary parasitoids: Tamarixia dryi, Psyllaephagus pulvinatus and another parasitoid of the genus Tamarixia. Molecular analysis showed that it is a new species closely related to T. dryi. Tamarixia dryi was the most abundant parasitoid but its relative abundance varied among sampling sites. The sex ratio (males/females) of T. dryi and Tamarixia sp. decreased with T. erytreae size and became female biased when psyllid nymphs were larger than 0.6 and 1.2 mm2, respectively. These parasitoids were attacked by three species of hyperparasitoids, Aphidencyrtus cassatus, Marietta javensis and a species of the genus Aphanogmus. Aphidencyrtus cassatus, the most abundant hyperparasitoid, tended to emerge from large nymphs, and adult females lived as long as those of T. dryi. The implications of these results are discussed within the framework of the introduction of T. dryi into Europe.


Assuntos
Citrus/parasitologia , Hemípteros/fisiologia , Animais , Código de Barras de DNA Taxonômico , Europa (Continente) , Feminino , Hemípteros/classificação , Hemípteros/crescimento & desenvolvimento , Hemípteros/parasitologia , Himenópteros/classificação , Himenópteros/fisiologia , Masculino , Ninfa/parasitologia , Ninfa/fisiologia , Controle Biológico de Vetores , Filogenia , Estações do Ano , África do Sul
11.
J Plant Res ; 132(4): 509-520, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31250145

RESUMO

The expression of plant secondary metabolism is strongly controlled by plant both in time and space. Although the variation of secondary metabolites, such as soluble and structural phenolics (e.g., lignins), has been largely observed in gall-inducing insects, and compared to their non-galled host organs, only a few datasets recording such variation are available. Accordingly, the relative importance of spatiotemporal variability in phenolic contents, and the influence of gall developmental stages on the original composition of host organs are poorly discussed. To address this knowledge gap, we histochemically determined the sites of polyphenol and lignin accumulation, and the polyphenol contents in three developmental stages of two calophyid galls and their correspondent host organs. Current results indicate that the compartmentalization of phenolics and lignins on Schinus polygama (Cav.) Cabrera follows a similar pattern in the two-calophyid galls, accumulating in the outer (the external tissue layers) and in the inner tissue compartments (the cell layers in contact with the gall chamber). The non-accumulation in the median compartment (median parenchyma layers of gall wall with vascular bundles, where gall inducer feeds) is important for the inducer, because its mouth apparatus enter in contact with the cells of this compartment. Also, the concentration of phenolics has opposite dynamics, decreasing in leaf galls and increasing in stem galls, in temporal scale, i.e., from maturation toward senescence. The concentration of phenolics in non-galled host organs, and in both galls indicated the extended phenotype of Calophya rubra (Blanchard) and C. mammifex Burckhardt & Basset (Hemiptera: Sternorrhyncha: Psylloidea: Calophyidae) over the same host plant metabolic potentiality.


Assuntos
Anacardiaceae/parasitologia , Hemípteros/parasitologia , Fenóis/metabolismo , Tumores de Planta/parasitologia , Anacardiaceae/metabolismo , Animais , Lignina/metabolismo , Polifenóis/metabolismo
12.
Neotrop Entomol ; 48(4): 633-644, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30900202

RESUMO

Parasitoids of Ceroplastes Gray were surveyed in the State of São Paulo, Brazil. Among the parasitoids reared, seven species of Metaphycus Mercet (Hymenoptera, Encyrtidae) were obtained. Metaphycusanaluciaesp. nov., M. floridensissp. nov., and M. grandissp. nov., are described as new species, and M. ceros Noyes, M. comes Noyes, M. dardanus Noyes, M. opis Noyes are recorded for the first time from Brazil. Ten new host-parasitoid associations are reported: M. analuciaesp. nov. parasitizing C. formicarius Hempel, C. glomeratus Peronti and C. iheringi Cockerel; M. ceros parasitizing C. cirripediformis Comstock; M. comes parasitizing C. formicarius; M. dardanus parasitizing C. glomeratus; M. floridensissp. nov. parasitizing C. floridensis; M. grandissp. nov. parasitizing C. grandis Hempel; and M. opis parasitizing C. glomeratus and C. janeirensis (Gray). A checklist of Metaphycus species associated with Ceroplastes, their distribution and host ranges are summarized and discussed.


Assuntos
Hemípteros/parasitologia , Vespas/anatomia & histologia , Vespas/classificação , Animais , Brasil , Feminino , Masculino , Clima Tropical
13.
J Cell Sci ; 132(6)2019 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-30886004

RESUMO

Vector-borne diseases cause over 700,000 deaths annually and represent 17% of all infectious illnesses worldwide. This public health menace highlights the importance of understanding how arthropod vectors, microbes and their mammalian hosts interact. Currently, an emphasis of the scientific enterprise is at the vector-host interface where human pathogens are acquired and transmitted. At this spatial junction, arthropod effector molecules are secreted, enabling microbial pathogenesis and disease. Extracellular vesicles manipulate signaling networks by carrying proteins, lipids, carbohydrates and regulatory nucleic acids. Therefore, they are well positioned to aid in cell-to-cell communication and mediate molecular interactions. This Review briefly discusses exosome and microvesicle biogenesis, their cargo, and the role that nanovesicles play during pathogen spread, host colonization and disease pathogenesis. We then focus on the role of extracellular vesicles in dictating microbial pathogenesis and host immunity during transmission of vector-borne pathogens.


Assuntos
Vetores Artrópodes , Vesículas Extracelulares , Doenças Transmitidas por Vetores , Amebíase/parasitologia , Amebíase/transmissão , Animais , Vetores Artrópodes/microbiologia , Vetores Artrópodes/parasitologia , Culicidae/microbiologia , Culicidae/parasitologia , Vetores de Doenças , Exossomos/imunologia , Exossomos/microbiologia , Exossomos/parasitologia , Vesículas Extracelulares/imunologia , Vesículas Extracelulares/microbiologia , Vesículas Extracelulares/parasitologia , Filariose/parasitologia , Filariose/transmissão , Hemípteros/microbiologia , Hemípteros/parasitologia , Interações Hospedeiro-Parasita/imunologia , Interações Hospedeiro-Parasita/fisiologia , Humanos , Imunomodulação , Leishmaniose/parasitologia , Leishmaniose/transmissão , Malária/parasitologia , Malária/transmissão , Psychodidae/microbiologia , Psychodidae/parasitologia , Tripanossomíase/parasitologia , Tripanossomíase/transmissão , Doenças Transmitidas por Vetores/microbiologia , Doenças Transmitidas por Vetores/parasitologia , Doenças Transmitidas por Vetores/transmissão , Viroses/microbiologia , Viroses/transmissão
14.
J Insect Sci ; 19(2)2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30822777

RESUMO

Brazil has a long history of the use of biological control (BC) of pests. The first attempt to use parasitoids was reported in the 1930s, and the first successful case dates to 1967. For a long period, chemical products were the most widespread control measure among Brazilian growers. This situation has gradually changed because of the lack of satisfactory control to manage certain pests, a slow change in the culture of growers, and some emblematic cases of the successful use of BC. The use of BC as a component of Integrated Pest Management is increasingly common. The present contribution summarizes the evolution of BC in Brazil, citing as an example the case of successful use of Cotesia flavipes (Cameron) (Hymenoptera: Braconidae), Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) and Trichogramma spp. It presents some data on the utilization of BC in the country, such as the case of sugarcane, for which microorganisms as well as macroorganisms are used; the use of Baculovirus in soybean, produced in mass-reared lepidopteran larvae; and the recent case of the control of Diaphorina citri Kuwayama (Hemiptera: Liviidae) by the parasitoid Tamarixia radiata. Finally, the prospects for wider use of BC in Brazil are discussed, together with the challenges involved in broadening the growers' use of this technology.


Assuntos
Controle de Insetos , Controle Biológico de Vetores , Vespas/fisiologia , Animais , Brasil , Hemípteros/parasitologia
15.
Pest Manag Sci ; 75(11): 3102-3112, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30924276

RESUMO

BACKGROUND: Aphytis melinus DeBach (Hymenoptera: Aphelinidae) is a highly effective biocontrol agent of the California red scale Aonidiella aurantii (Maskell) (Hemiptera: Diaspididae). It is commercially reared and used for augmentative releases within integrated pest management programs. However, mass rearing of biocontrol agents can result in population bottlenecks and high levels of inbreeding and/or adaptation to the factitious rearing conditions. Although these factors can all negatively impact field performance of biocontrol agents, few empirical studies have examined the genetic consequences of mass rearing. We used double-digest RAD sequencing (ddRADseq) to investigate the effect of traditional mass rearing on genetic variation among insectary colonies of A. melinus relative to wild populations in native (Pakistan) and introduced (California) ranges. RESULTS: Analyses of up to 9700 single nucleotide polymorphisms (SNPs) revealed that insectary populations had less genomic variation than introduced populations. This was evidenced by fewer private alleles, reduced heterozygosity, and greater missing data in the insectary populations. Further, California insectaries formed a distinct genomic cluster relative to the other samples, a surprising result given that the insectary colonies were putatively established at different times and from different source populations. These differences were evident across most data sets also after we filtered out contaminant DNA from the most common host species (Aspidiotus nerii Bouché and A. aurantii). CONCLUSION: We hypothesize that this pattern would only result if: (i) directional selection for 'captive' phenotypes produces convergent patterns of genomic variation across insectaries; or (ii) the California insectary colonies were all founded from a unifying source population and/or that the insectaries regularly exchange 'genetic' stocks. We show that RADseq is an effective method to investigate the effects of mass rearing on genetics of biocontrol agents. © 2019 Society of Chemical Industry.


Assuntos
Estudo de Associação Genômica Ampla , Hemípteros/parasitologia , Controle de Insetos , Controle Biológico de Vetores , Polimorfismo de Nucleotídeo Único , Vespas/genética , Animais , California , Paquistão
16.
Neotrop Entomol ; 48(3): 476-483, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30607872

RESUMO

Encarsia formosa (Gahan) (Hymenoptera: Aphelinidae) has been used to control for the biological control of Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) in greenhouse tomato crops. One aspect that influences the success of this method is the continuous availability of large numbers of E. formosa that enable the grower to release them at the proper time and in the quantity required. Rearing facilities of this parasitoid require reliable and low time-consuming methods for scouting populations of insects to forecast production. In this work, we develop a time-effective method for estimating insect populations in a mass rearing system with T. vaporariorum, using common bean plants as hosts. The population density of T. vaporariorum in highly infested leaves was determined to be 27.5 nymphs/cm2 using a linear regression model. Using an effort curve and binomial distribution, we determined that 14 and 54 leaves are the minimum number of sampling units required to estimate the T. vaporariorum nymphs and E. formosa pupae populations, respectively. A wasp ratio was determined by dividing the number of E. formosa produced by the total number used in the process. This index was higher when less than 7000 E. formosa were released per production batch in 1 week. When high populations of E. formosa are released in a batch, the production efficiency decreases, producing fewer new adults per adult used in the batch.


Assuntos
Hemípteros/parasitologia , Controle Biológico de Vetores , Vespas/fisiologia , Animais , Ninfa , Phaseolus , Densidade Demográfica , Pupa
17.
PLoS One ; 14(1): e0209828, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30650162

RESUMO

Salinity is increasing in aquatic ecosystems in the Mediterranean region due to global change, and this is likely to have an important impact on host-parasite interactions. Here we studied the relationships between infection by ectoparasitic water mites and salinity variation, on survival and fecundity of water boatmen Corixidae in the laboratory. Larvae of Sigara lateralis parasitised by larval mites (Hydrachna skorikowi) had lower survivorship, and failed to moult to the adult stage. In adult corixids (S. lateralis and Corixa affinis) fitness was reduced at high salinities and in individuals infected by H. skorikowi, both in terms of survival and fecundity. We also found evidence for parasitism-salinity interactions. Our results suggest that ongoing increases in salinity in Mediterranean ponds due to climate change and water abstraction for agriculture or urban use have a strong impact on water bugs, and that their interactions with ectoparasites may modify salinity effects.


Assuntos
Heterópteros/parasitologia , Infestações por Ácaros/parasitologia , Estresse Salino/fisiologia , Animais , Mudança Climática , Ecossistema , Ectoparasitoses , Fertilidade/fisiologia , Hemípteros/metabolismo , Hemípteros/parasitologia , Heterópteros/metabolismo , Interações Hospedeiro-Parasita , Larva , Mar Mediterrâneo , Infestações por Ácaros/metabolismo , Ácaros , Salinidade , Água
18.
J Invertebr Pathol ; 165: 4-12, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-29196232

RESUMO

Historically, greenhouse floriculture has relied on synthetic insecticides to meet its pest control needs. But, growers are increasingly faced with the loss or failure of synthetic chemical pesticides, declining access to new chemistries, stricter environmental/health and safety regulations, and the need to produce plants in a manner that meets the 'sustainability' demands of a consumer driven market. In Canada, reports of thrips resistance to spinosad (Success™) within 6-12 months of its registration prompted a radical change in pest management philosophy and approach. Faced with a lack of registered chemical alternatives, growers turned to biological control out of necessity. Biological control now forms the foundation for pest management programs in Canadian floriculture greenhouses. Success in a biocontrol program is rarely achieved through the use of a single agent, though. Rather, it is realized through the concurrent use of biological, cultural and other strategies within an integrated plant production system. Microbial insecticides can play a critical supporting role in biologically-based integrated pest management (IPM) programs. They have unique modes of action and are active against a range of challenging pests. As commercial microbial insecticides have come to market, research to generate efficacy data has assisted their registration in Canada, and the development and adaptation of integrated programs has promoted uptake by floriculture growers. This review documents some of the work done to integrate microbial insecticides into chrysanthemum and poinsettia production systems, outlines current use practices, and identifies opportunities to improve efficacy in Canadian floriculture crops.


Assuntos
Agentes de Controle Biológico , Horticultura , Controle de Insetos , Controle Biológico de Vetores/métodos , Animais , Bacillus thuringiensis/patogenicidade , Beauveria/patogenicidade , Canadá , Chrysanthemum/crescimento & desenvolvimento , Euphorbia/crescimento & desenvolvimento , Fungos/patogenicidade , Hemípteros/microbiologia , Hemípteros/parasitologia , Horticultura/métodos , Horticultura/tendências , Insetos/microbiologia , Insetos/parasitologia , Inseticidas , Metarhizium/patogenicidade , Nematoides/patogenicidade , Nucleopoliedrovírus/patogenicidade , Feromônios , Tisanópteros/microbiologia , Tisanópteros/parasitologia , Vespas
19.
Insect Sci ; 26(2): 351-365, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28842961

RESUMO

Insect herbivore outbreaks frequently occur and this may be due to factors that restrict top-down control by parasitoids, for example, host-parasitoid asynchrony, hyperparasitization, resource limitation and climate. Few studies have examined host-parasitoid density relationships during an insect herbivore outbreak in a natural ecosystem with diverse parasitoids. We studied parasitization patterns of Cardiaspina psyllids during an outbreak in a Eucalyptus woodland. First, we established the trophic roles of the parasitoids through a species-specific multiplex PCR approach on mummies from which parasitoids emerged. Then, we assessed host-parasitoid density relationships across three spatial scales (leaf, tree and site) over one year. We detected four endoparasitoid species of the family Encyrtidae (Hymenoptera); two primary parasitoid and one heteronomous hyperparasitoid Psyllaephagus species (the latter with female development as a primary parasitoid and male development as a hyperparasitoid), and the hyperparasitoid Coccidoctonus psyllae. Parasitoid development was host-synchronized, although synchrony between sites appeared constrained during winter (due to temperature differences). Parasitization was predominantly driven by one primary parasitoid species and was mostly inversely host-density dependent across the spatial scales. Hyperparasitization by C. psyllae was psyllid-density dependent at the site scale, however, this only impacted the rarer primary parasitoid. High larval parasitoid mortality due to density-dependent nymphal psyllid mortality (a consequence of resource limitation) compounded by a summer heat wave was incorporated in the assessment and resulted in density independence of host-parasitoid relationships. As such, high larval parasitoid mortality during insect herbivore outbreaks may contribute to the absence of host density-dependent parasitization during outbreak events.


Assuntos
Hemípteros/parasitologia , Interações Hospedeiro-Parasita , Animais , Feminino , Cadeia Alimentar , Masculino , Ninfa/parasitologia , Dinâmica Populacional
20.
Insect Sci ; 26(1): 119-127, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28590080

RESUMO

Two parasitoids attacking nymphs of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) and Diaphorencyrtus aligarhensis (Shafee, Alam & Agarwal) (Hymenoptera: Encyrtidae) are being released in California, USA in a classical biological control program. To evaluate the effect of multiple parasitoid species on D. citri mortality, we conducted mesocosm experiments under controlled conditions using a complete block design with 6 treatments (D. citri nymphs exposed to: no parasitoids; D. aligarhensis or T. radiata alone; D. aligarhensis or T. radiata released first (by 48 h); and both species released simultaneously). Parasitism of D. citri nymphs by T. radiata exceeded 60% and was unchanged when D. aligarhensis were present. Parasitism by D. aligarhensis was greatest when T. radiata was absent (∼28%) and was reduced in all treatments with T. radiata present (<3%). D. citri mortality and parasitoid-related mortality of D. citri was consistent across parasitoid treatments. Laboratory results suggest that competition between D. aligarhensis and T. radiata is asymmetric and favors T. radiata. It may be difficult for D. aligarhensis to contribute significantly to D. citri biological control where T. radiata is present. However, results reported here suggest that competition between T. radiata and D. aligarhensis is not likely to reduce parasitism by T. radiata or reduce parasitoid-induced mortality of D. citri.


Assuntos
Comportamento Competitivo , Hemípteros/parasitologia , Interações Hospedeiro-Parasita , Controle Biológico de Vetores , Vespas/fisiologia , Animais , Citrus , Feminino , Espécies Introduzidas , Ninfa/parasitologia
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