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1.
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
2.
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
3.
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
4.
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
5.
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
6.
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
7.
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
8.
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
9.
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
10.
Pest Manag Sci ; 75(3): 702-707, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30094920

RESUMO

BACKGROUND: Eretmocerus warrae (Hymenoptera: Aphelinidae) is a parasitoid of the glasshouse whitefly, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae). Here, we compare its potential as a biological control agent at high temperatures to that of Encarsia formosa (Hymenoptera: Aphelinidae), a wasp which is widely sold for control of T. vaporariorum. RESULTS: Eretmocerus warrae attained the highest estimated developmental rate at 31.4 °C and the maximum oviposition rate at 30.5 °C. Developmental times of E. warrae at fluctuating temperatures that simulate night-day patterns were similar to those predicted based on constant temperatures. Above the optimum temperature, E. warrae tolerated higher constant temperatures than En. formosa during development and as adults. Using a ramping temperature approach, the critical thermal maximum for adult E. warrae was significantly higher than that of adult En. formosa. CONCLUSION: Eretmocerus warrae is better adapted to high temperatures than En. formosa, and could therefore be a complementary or superior biological control agent during summer months in hot regions. © 2018 Society of Chemical Industry.


Assuntos
Hemípteros/parasitologia , Temperatura Alta , Controle Biológico de Vetores/métodos , Vespas/fisiologia , Animais , Lycopersicon esculentum , Ninfa/parasitologia , Oviposição/fisiologia , Vespas/crescimento & desenvolvimento
11.
Environ Entomol ; 48(1): 134-140, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30371766

RESUMO

The outbreak of the coconut scale insect Aspidiotus rigidus Reyne (Hemiptera: Encyrtidae) posed a serious threat to the coconut industry in the Philippines. In this article, we modeled the interaction between A. rigidus and its parasitoid Comperiella calauanica Barrion, Almarinez, Amalin (Hymenoptera: Encyrtidae) using a system of ordinary differential equations based on a Holling type III functional response. The equilibrium points were determined, and their local stability was examined. Numerical simulations showed that C. calauanica may control the population density of A. rigidus below the economic injury level.


Assuntos
Hemípteros/parasitologia , Interações Hospedeiro-Parasita , Modelos Biológicos , Vespas/fisiologia , Animais
12.
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
13.
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
14.
J Insect Sci ; 18(6)2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30517690

RESUMO

Little is known about Dalbulus maidis (DeLong) egg parasitoids within maize fields, in the edge zones that surround these fields, and the parasitism on D. maidis eggs oviposited on different maize varieties. The objectives of the present study were first to understand which egg parasitoid species attack D. maidis eggs within maize fields and in the surrounding edge zones, and second, to compare parasitism on two maize varieties (land race Ancho-pozolero and hybrid Tigre-Asgrow) during the maize-growing wet season. We used maize plants with sentinel eggs to attract the egg parasitoids in two consecutive wet seasons, in 2015 and 2016. In 2015, Anagrus sp. (Hymenoptera: Mymaridae) and Paracentrobia sp. (Hymenoptera: Trichogrammatidae) parasitized D. maidis eggs within the maize field and on its edges. However, much more parasitism was seen within the maize agroecosystem than in the maize edge zones. In 2016, two Mymaridae species, Anagrus columbi Perkins and Anagrus sp, and two Trichogrammatidae genera, Pseudoligosita sp. and Paracentrobia sp., attacked the D. maidis eggs laid on maize hybrids but not those oviposited on the maize land race. Our findings indicate that parasitism of corn leafhopper eggs differs with agroecosystem location and maize varieties.


Assuntos
Ecossistema , Hemípteros/parasitologia , Himenópteros/fisiologia , Óvulo/parasitologia , Zea mays/parasitologia , Agricultura , Animais , México , Estações do Ano
15.
Sci Rep ; 8(1): 15677, 2018 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-30356173

RESUMO

Foraging parasitoid females should preferentially oviposit on hosts most suitable for progeny development to maximize their fitness. However, the introduction of a new host species may disrupt the link between the reliability of the cues and the expected adaptive outcome of female choice, leading to an evolutionary trap. This mismatch between behavioural acceptance and lack of development exists for North American and European egg parasitoids (Scelionidae) that encounter invasive Halyomorpha halys in areas where this exotic host has recently established. To explain this mismatch, we utilized an L9 orthogonal array design to assess and rank the influence of several critical factors characterizing host resource (host species, egg age, egg status, and surface wash) on behaviour (acceptance, patch residence and patch exploitation) and development of North American native Trissolcus euschisti egg parasitoid. Our results indicate that the host egg age is most important for behaviour, but is least influential for development of the progeny. This study suggests that the maladaptive decision to oviposit in an unsuitable host is due to a mismatch between the cues that females use, and the subsequent expected outcome of this choice. Therefore, it is the relative importance of individual factors when assessed simultaneously that influences the decision-making of female parasitoids.


Assuntos
Hemípteros/parasitologia , Interações Hospedeiro-Parasita/fisiologia , Himenópteros/crescimento & desenvolvimento , Oviposição/fisiologia , Análise de Variância , Animais , Sinais (Psicologia) , Tomada de Decisões/fisiologia , Feminino , Especificidade de Hospedeiro/fisiologia , Comportamento de Busca por Hospedeiro , Óvulo/fisiologia , Comportamento Sexual Animal/fisiologia
16.
Environ Entomol ; 47(6): 1451-1458, 2018 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-30256925

RESUMO

This study evaluated how the size of the egg mass and the parasitoids prior exposure to eggs influenced parasitism rates by Gryon pennsylvanicum Ashmead (Hymenoptera: Scelionidae) on egg masses of two squash bug species, Anasa tristis DeGeer and Anasa armigera Say (Hemiptera: Coreidae). G. pennsylvanicum is the primary egg parasitoid of A. tristis. There were no published reports available on egg parasitism of A. armigera. In choice tests, there was no difference in host acceptance by G. pennsylvanicum of egg masses of the two squash bug species. In no-choice tests, overall parasitism rates were significantly higher on A. armigera egg masses than on A. tristis egg masses. Naive parasitoids had significantly higher parasitism rates than experienced parasitoids on egg masses of both squash bug species. In a comparison of parasitism rates of field-collected and laboratory-tested A. tristis egg masses of different sizes, parasitism rates were similar in the field and in the laboratory, with the exception of egg masses with > 25 eggs. Only 17.9% of eggs were parasitized in the laboratory, compared with 36.4% in the field. Results of this study indicate that transient egg limitation prevents G. pennsylvanicum from ovipositing in every available host egg in large squash bug egg masses. The low parasitism rate of G. pennsylvanicum on large egg masses may limit its effectiveness as a biological control agent of squash bugs.


Assuntos
Hemípteros/parasitologia , Interações Hospedeiro-Parasita , Oviposição , Óvulo/parasitologia , Vespas/fisiologia , Animais , Feminino , Hemípteros/fisiologia
17.
PLoS One ; 13(9): e0204467, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30261003

RESUMO

Blastocrithidia papi is a unique trypanosomatid in that its life cycle is synchronized with that of its host, and includes an obligate stage of development in Malpighian tubules (MTs). This occurs in firebugs, which exited the winter diapause. In the short period, preceding the mating of overwintered insects, the flagellates penetrate MTs of the host, multiply attached to the epithelial surface with their flagella, and start forming cyst-like amastigotes (CLAs) in large agglomerates. By the moment of oviposition, a large number of CLAs are already available in the rectum. They are discharged on the eggs' surface with feces, used for transmission of bugs' symbiotic bacteria, which are compulsorily engulfed by the newly hatched nymphs along with the CLAs. The obligate development of B. papi in MTs is definitely linked to the life cycle synchronization. The absence of peristalsis allow the trypanosomatids to accumulate and form dense CLA-forming subpopulations, whereas the lack of peritrophic structures facilitates the extensive discharge of CLAs directly into the hindgut lumen. The massive release of CLAs associated with oviposition is indispensable for maximization of the infection efficiency at the most favorable time point.


Assuntos
Hemípteros/parasitologia , Interações Hospedeiro-Patógeno , Túbulos de Malpighi/parasitologia , Trypanosomatina/crescimento & desenvolvimento , Animais , Células Epiteliais/parasitologia , Células Epiteliais/ultraestrutura , Fezes/parasitologia , Hemípteros/ultraestrutura , Intestinos/parasitologia , Intestinos/ultraestrutura , Estágios do Ciclo de Vida , Túbulos de Malpighi/ultraestrutura , Oviposição , Trypanosomatina/ultraestrutura
18.
Environ Entomol ; 47(6): 1493-1500, 2018 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-30165469

RESUMO

Parasitoid wasps released as biological control agents may experience strong interspecific competition, which can lead to a reduction in pest control. The effects of competition can be mitigated if niche partitioning exists between species, such as parasitism preferences for different host stages. We examined host stage preferences for the parasitoids Encarsia noyesi Hayat (Hymenoptera: Aphelinidae), Idioporus affinis LaSalle and Polaszek (Hymenoptera: Pteromalidae), and Entedononecremnus krauteri Zolnerowich and Rose (Hymenoptera: Eulophidae). These parasitoids were introduced to the United States to control the giant whitefly Aleurodicus dugesii Cockerell (Hemiptera: Aleyrodidae), a pest of many economically important plants. Host stage preferences were examined using multiple metrics including: parasitism rates, relative preferences, handling times, and initial stage parasitism frequency. The data indicated differences in parasitoid preference hierarchies for the four A. dugesii nymphal stages. All A. dugesii nymphal stages were parasitized by I. affinis, which exhibited preference for the third instar. Unlike I. affinis, the first instar was not parasitized by E. noyesi, and its preference hierarchy differed with the fourth instar being the most preferred stage. The observed host-use breadth of E. krauteri was the narrowest observed of the three parasitoid species, only parasitizing the fourth and third instars, with a clear preference for the former. The observed differences in host-use breadth and stage preferences between parasitoid species in this system may promote their long-term coexistence in the field and facilitate biological control. Potential factors underlying the preferences exhibited by these parasitoids and their implications for biological control are discussed.


Assuntos
Hemípteros/parasitologia , Interações Hospedeiro-Parasita , Controle Biológico de Vetores , Vespas/fisiologia , Animais , Comportamento de Escolha , Feminino , Hibiscus , Ninfa/parasitologia
19.
Acta Trop ; 185: 251-254, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29859748

RESUMO

As Chagas disease has no cure, vector control is the most effective method of preventing this neglected disease. Generally the anatomical teratologies are associated with hormonal dysfunction of the corpus allatum (juvenile hormone), presents genetic basis or unfavorable conditions, and are recessive and not sex linked. Thus, we characterize the male gonads and spermatogenesis of triatomines with anatomical teratologies to evaluate if the malformations interfere in the gametogenesis of these vectors. All teratogenic triatomines analyzed did not present presented gonadal dysgenesis and alterations in spermatogenesis. Thus, we characterize the presence of anatomical teratologies in some species of triatomines and demonstrate that these malformations in the external morphology do not interfere in the gonads and gametogenesis of these vectors. In addition, although new studies with the corpus allatum should be conducted we suggesting that the use of juvenile hormones does not present effectiveness in the reproductive control of these vectors.


Assuntos
Doença de Chagas/parasitologia , Gônadas/anatomia & histologia , Hemípteros/fisiologia , Espermatogênese , Triatominae/fisiologia , Animais , Vetores de Doenças , Hemípteros/parasitologia , Insetos Vetores/parasitologia , Masculino , Triatominae/parasitologia
20.
J Econ Entomol ; 111(3): 1121-1130, 2018 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-29846649

RESUMO

The genus Physokermes Targioni Tozzetti includes species that are distributed in the Holarctic region and feed on conifers. The recently described scale Physokermes hellenicus (Kozár and Gounari) (Hemiptera: Coccidae) is an endemic species of Greece whose host plants are fir trees of the genus Abies (Pinales: Pinaceae). It is considered as beneficial scale insect species since its honeydew secretions are exploited by honeybees leading to the production of a special honey with important physicochemical characteristics. Since there are no previous data on the natural enemies of P. hellenicus, an investigation was carried out during 2013 in forested areas of eight mountains in south and central Greece aiming to correlate the presence of P. hellenicus with certain parasitoids and predators. Seven species of Encyrtidae, Eulophidae, Pteromalidae, and Eurytomidae (Hymenoptera); five species of Anthribidae and Coccinellidae (Coleoptera); and four species of Dictinidae, Linyphiidae, and Theridiidae (Araneae) were identified. Twelve of them were identified at the species level while four at the genus level. Among them Microterys lunatus (Dalman) (Hymenoptera: Encyrtidae), Pseudorhopus testaceus (Ratzeburg) (Hymenoptera: Encyrtidae), and Anthribus fasciatus Forster (Coleoptera: Anthribidae) were the most abundant natural enemies of P. hellenicus adult female while Metaphycus unicolor Hoffer (Hymenoptera: Encyrtidae) and Trichomasthus sp. (Hymenoptera: Encyrtidae) were found to parasitize P. hellenicus male nymph. Cinetata gradata (Simon) (Araneae: Linyphiidae) is reported for first time in the Greek arachnofauna. Our results suggest that the abundance of the fir scale P. hellenicus could be affected by a complex of parasitoid and predator species of different taxa. Future long-term research on these species in relation with abiotic factors would help to understand possible fluctuation of the scale's population.


Assuntos
Besouros/fisiologia , Hemípteros/fisiologia , Hemípteros/parasitologia , Interações Hospedeiro-Parasita , Controle Biológico de Vetores , Comportamento Predatório , Aranhas/fisiologia , Vespas/fisiologia , Animais , Besouros/crescimento & desenvolvimento , Feminino , Cadeia Alimentar , Grécia , Hemípteros/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/parasitologia , Aranhas/crescimento & desenvolvimento , Vespas/crescimento & desenvolvimento
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