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Biología y ciclo reproductivo de Praon pos. occidentale (Hymenoptera: Braconidae) parasitoide de Macrosiphum euphorbiae (Hemiptera:Aphididae)
Arias,Diana; Cantor,Fernando; Cure,José Ricardo; Rodríguez,Daniel;
Agronomía Colombiana , 2009,
Abstract: previous research studies conducted in commercial rose crops in the bogota plateau have shown the presence of aphids parasitized by wasps of the genus praon. the present research studied the biology and reproductive cycle of praon sp. under laboratory conditions, at six constant temperatures (15, 17, 20, 25, 28 and 30°c). the parasitized aphids were kept in incubators at the selected temperatures, under a regime of alternate light and darkness 12 hour periods. they were periodically dissected to determine the development stage of the parasitoid, which allowed determining the average duration of all such stages, from egg to adult. at all temperatures, except for 15°c, the results showed complete development of all biological stages, for which a mathematical model of development rate as a function of temperature was fitted. the eggs were observed to need the highest minimum temperature threshold to complete their development. both males and females were observed to live longer at low temperatures. regarding sex effect, females were found to live longer than males at all temperatures. a larger number of males was observed at 17 and 20°c, while females were more numerous at 25, 28 and 30°c.
Capacidad parasítica de Praon pos. occidentale (Hymenoptera: Braconidae) sobre Macrosiphum euphorbiae (Hemiptera: Aphididae) en condiciones de laboratorio  [cached]
Aragón Sandra,Cantor Fernando,Cure José Ricardo,Rodriguez Daniel
Agronomía Colombiana , 2007,
Abstract: Praon pos. occidentale es un parasitoide promisorio para regular poblaciones de áfidos Macrosiphum euphorbiae en cultivos comerciales bajo invernadero de rosas. Se evaluó la capacidad parasítica de P. pos. occidentale bajo tres temperaturas constantes (18, 25 y 28oC) y variando la densidad de su hospedero (5, 10, 20, 40, 80 y 150). En cada unidad experimental se liberó una pareja del parasitoide con 24 horas de edad y se mantuvieron durante 24 horas en incubadoras graduadas a cada temperatura en evauación, con 12 horas de luz y 12 de oscuridad. Se registró el número de áfidos parasitados y se permitió el desarrollo de los huevos depositados hasta adulto. Se estimó la tasa instantánea de búsqueda (a’) y el tiempo de manipulación (Th) a partir de los cuales se ajustó el modelo de respuesta funcional tipo II para cada temperatura. La tasa instantánea de búsqueda (a’) fue más alta a 18oC con un valor de 0,1081, seguida de 28oC con 0,0323 y 25oC con 0,0103. El tiempo de manipulación (Th) más corto fue el que se presentó a 25oC de 4,8913, seguido de 28o C con un tiempo de 5,7579 y 18oC con 8,2697. El máximo número de individuos parasitados estimado fue de 4,9 a 25oC. A 18oC el 60% de los áfidos parasitados alcanzó la emergencia del adulto, el 74,2% a 25oC y el 88% a 28oC. No existe ningún efecto significativo de la densidad del hospedero ni de la temperatura en la proporción sexual de Praon pos. Occidentale.
Capacidad parasítica de Praon pos. occidentale (Hymenoptera: Braconidae) sobre Macrosiphum euphorbiae (Hemiptera: Aphididae) en condiciones de laboratorio
Aragón,Sandra; Cantor,Fernando; Cure,José; Rodriguez,Daniel;
Agronomía Colombiana , 2007,
Abstract: praon pos. occidentale is a promising parasitoid that regulates populations of the aphid macrosiphum euphorbiae in commercial rose production under greenhouse conditions. it was evaluated the parasitic ability of praon pos. occidentale under three constant temperatures 18, 25 and 28oc and varying host density 5, 10, 20, 40, 80 y 150. each experimental unit consisted of one couple of the parasitoid with 24 hours old kept during 24 hours in graduated incubators with a 12:12 photoperiod. the number of parasitized aphids was recorded and development of the laid eggs was allowed. the instantaneous rate of search (a′) and the handling time (th) of the model of functional response type ii were estimated. the instantaneous rate of search (a′) was higher at 18oc with 0.1081, followed by 0.0323 at 28o c and 0.0103 at 25oc. the shorter handling time (th) was 4.8913 at 25oc, followed by 5.7579 at 28oc and 8.2697 at 18oc. the maximum number of parasitized aphids estimated was 4.9 at 25oc. at 18oc the 60% of the parasitized aphids reached the adult emergence, whereas this number was 74.2% at 25oc and 88% at 28oc. there was no significant effect of the host density, neither temperature on the sexual ratio of praon pos. occidentale was recorded.
Cytogenetic and molecular analysis of the holocentric chromosomes of the potato aphid Macrosiphum euphorbiae (Thomas, 1878)  [cached]
Valentina Monti,Gian Carlo Manicardi,Mauro Mandrioli
Comparative Cytogenetics , 2011, DOI: 10.3897/compcytogen.v5i3.1724
Abstract: Cytogenetic and molecular investigations on the holocentric chromosomes of the aphid Macrosiphum euphorbiae (Thomas, 1878) have been carried out using silver staining and C-banding (followed by chromomycin A3 and DAPI staining) in order to improve our knowledge about the structure of aphid chromosomes. The C-banding pattern is peculiar since only the two X chromosomes and a single pair of autosomes presented heterochromatic bands. Silver staining and FISH with the 28S rDNA probe localized the rDNA genes on one telomere of each X chromosome that were also brightly fluorescent after chromomycin A3 staining of C-banded chromosomes, whereas all other heterochromatic bands were DAPI positive. Interestingly, a remarkable nucleolar organizing region (NOR) heteromorphism was present making the two X chromosomes easily distinguishable. Southern blotting and FISH assessed the presence of the (TTAGG)n repeat at the ends of all the M. euphorbiae chromosomes. Karyotype analysis showed that all males possessed the X chromosome with the larger amount of rDNA suggesting a non-Mendelian inheritance of the two X chromosomes.
Effect of Different Variation of NH4+ Compared to N (NH4+ + NO3–) Fertilization of Tomato (Lycopersicum esculentum) Cultivated in Inert Media on the Fecundity of the Aphids Macrosiphum euphorbiae (Homptera-Aphididae)
A. Latigui,A. Dellal
American Journal of Plant Physiology , 2009,
Abstract: Changes of 0, 20 and 35% of NH4+ compared to N (NH4++NO3–) nutrient solutions of Lycopersicum esculentum L. cultivated on inert media on the multiplication of Macrosiphum euphorbiae (Aphididae Homomptera) were tested. The use of 0% NH4+ decreased 12% the fertility of aphids compared to 20% NH4+ and 17% compared to 35% NH4+. Reproduction of aphids on the leaves of flowering inflorescence increased 33% compared to that of the fruit setting inflorescence and 40% compared to that of the magnification inflorescence and 52% relative to the fixed level. The interruption of the fertilization of plant and its replacement by water for 4 days decreased 45% the fertility of aphids in the fourth inflorescence and 36% in the seventh inflorescence.
Foraging Behavior of Praon volucre (Hymenoptera: Braconidae) a Parasitoid of Sitobion avenae (Hemiptera: Aphididae) on Wheat  [PDF]
Afrooz Farhad,Ali Asghar Talebi,Yaghoub Fathipour
Psyche , 2011, DOI: 10.1155/2011/868546
Abstract: Host stage preference, functional response and, mutual interference of Praon volucre (Haliday) (Hym.:?Braconidae) parasitizing the grain aphid, Sitobion avenae (Fabricius) (Hem.:?Aphididae), were investigated under laboratory conditions. Host stage preference was evaluated at °C, % relative humidity and a photoperiod of 16:8?h (L?:?D), under choice and no-choice tests. Functional response was done under five constant temperatures (10, 15, 20, 25, and 30°C), % relative humidity and a photoperiod of 16:8?h. (L?:?D). Praon volucre parasitized all nymphal instars and adults of the grain aphid but strongly preferred to oviposit into second-instar nymphs in both choice and no-choice conditions. Results of logistic regression revealed a type II functional response for all temperatures tested. The handling time ( ) and searching efficiency ( ) were estimated using the Rogers equation. The maximum estimate of searching efficiency occurred at 15°C and 20°C (both ?h?1) and decreased to ?h?1 at °C. The minimum estimate of handling time was ?h at 25°C and increased to ?h at °C. The maximum rate of parasitism was 23.52 aphids/female/day at 25°C. With parasitoid density increasing from 1 to 8, the per capita searching efficiency decreased from 0.12?h?1 to 0.06?h?1. The results suggested that P. voluvre has the potential to be a biocontrol agent of S. avenae. However, evaluation of foraging behavior warrants further investigation under field conditions. 1. Introduction The grain aphid, Sitobion avenae (Fabricius), is a cosmopolitan species [1]. This aphid causes direct damage by sucking plant sap and indirect damage by either excretion of honeydew or the transmission of viruses. It is found on many different species of Poaceae [2]. Chemical control has been the major tool for the control of aphids. However, biological control strategies are being increasingly applied because of rapid development of insecticides resistance in aphids and because of the effects of pesticides on natural enemies [3]. Parasitoids are important in biological control of cereal aphids [4], and several attempts have been made in introduction [5] and augmentative release of cereal aphid parasitoids [6]. Parasitoids are considered to be especially important in suppressing aphid populations earlier in the season because their appearances precede those of predators [7]. All members of the subfamily Aphidiinae (Hymenoptera: Braconidae) are important parasitoids of aphid species [8]. The genus Praon Haliday is one of the largest Aphidiinae genera with more than 50 described species worldwide [9].
Metabolic and Proteomic Profiling of Diapause in the Aphid Parasitoid Praon volucre  [PDF]
Hervé Colinet, David Renault, Blandine Charoy-Guével, Emmanuelle Com
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0032606
Abstract: Background Diapause, a condition of developmental arrest and metabolic depression exhibited by a wide range of animals is accompanied by complex physiological and biochemical changes that generally enhance environmental stress tolerance and synchronize reproduction. Even though some aspects of diapause have been well characterized, very little is known about the full range of molecular and biochemical modifications underlying diapause in non-model organisms. Methodology/Principal Findings In this study we focused on the parasitic wasp, Praon volucre that exhibits a pupal diapause in response to environmental signals. System-wide metabolic changes occurring during diapause were investigated using GC-MS metabolic fingerprinting. Moreover, proteomic changes were studied in diapausing versus non-diapausing phenotypes using a combination of two-dimensional differential gel electrophoresis (2D-DIGE) and mass spectrometry. We found a reduction of Krebs cycle intermediates which most likely resulted from the metabolic depression. Glycolysis was galvanized, probably to favor polyols biosynthesis. Diapausing parasitoids accumulated high levels of cryoprotective polyols, especially sorbitol. A large set of proteins were modulated during diapause and these were involved in various functions such as remodeling of cytoskeleton and cuticle, stress tolerance, protein turnover, lipid metabolism and various metabolic enzymes. Conclusions/Significance The results presented here provide some first clues about the molecular and biochemical events that characterize the diapause syndrome in aphid parasitoids. These data are useful for probing potential commonality of parasitoids diapause with other taxa and they will help creating a general understanding of diapause underpinnings and a background for future interpretations.
Germination and mycelial growth of Bipolaris euphorbiae Muchovej & Carvalho as influenced by herbicides and surfactants
Nemoto Marta Cecília Mallasen,Nahas Ely,Pitelli Robinson Antonio,Coelho Lisias
Brazilian Journal of Microbiology , 2002,
Abstract: Bipolaris euphorbiae Muchovej & Carvalho can be combined with herbicide in order to control a large spectrum of weed species, being a strong candidate for the biocontrol of Euphorbia heterophylla L. (milk weed). The fungus release can be combined with herbicide in order to control a broader spectrum of weed species. Thus, laboratory experiments were set up to study the feasibility of using tank mixes of B. euphorbiae spores with herbicides or surfactants recommended for soybean. Mycelial growth and conidia germination were evaluated in PDA medium enriched with the herbicides oxasulfuron (80 g/ha), glyphosate (4 L/ha), bentazon (1.5 L/ha), fomesafen (1 L/ha), chlorimuron-ethyl (80 g/ha), lactofen (1 L/ha) and imazetaphyr (1 L/ha), and the surfactants Energic (2 ml/L), Aterbane (2.5 ml/L), Silwet L-77Ag (1 ml/L), Herbitensil (2 ml/L) and Natur L'óleo (10 ml/L). Dilution of the herbicides at 50% and 25% were evaluated based on solution consumption of 300 L/ha. The surfactants were evaluated only in the recommended concentrations. Mycelial growth was not affected by bentazon and fomesafen and slightly by oxasulfuron. However, glyphosate and the surfactants Energic, Herbitensil and Aterbane strongly reduced its growth. The reduction observed on imazetaphyr enriched medium was intermediate and the Natur L'óleo promoted mycelial growth. All of the surfactants allowed B. euphorbiae conidia germination equivalent to that reached in the presence of water. Energic and Herbitensil caused an expressive retardation on spore germination. The germinative process only began after 120 minutes in the presence of Herbitensil. In relation to the herbicides, it was observed that only in the presence of glyphosate and imazetaphyr the conidia germination did not follow the trend of the treatment with water.
Crescimento e esporula??o de Bipolaris euphorbiae cultivado sob diferentes condi??es nutricionais
Penariol, Mara Cristina;Monteiro, Antonio Carlos;Pitelli, Robinson Antonio;
Ciência Rural , 2008, DOI: 10.1590/S0103-84782008000700016
Abstract: bipolaris euphorbiae muchovej & carvalho is considered a potential bioagent for control of selvage peanuts (euphorbia heterophylla l.) on soybean crops in brazil. however, little is known about the nutritional characteristics of this fungus. the main objective of this research was to evaluate different sources of carbon (glucose, starch, sucrose, lactose and maltose), of nitrogen (sodium nitrate, ammonium nitrate, ammonium sulphate, bi-basic ammonium phosphate, ammonium chloride), of phosphorus (monobasic potassium phosphate, bi-basic potassium phosphate, calcium phosphate, sodium phosphate, phosphoric acid, ammonium phosphate) and addition of organic sources of macro and micronutrients as supplement in the culture medium for the growth and sporulation of b. euphorbiae. starch was the carbon source that promoted the greater fungus growth and was considered the most favorable to sporulation. the nitrogen source sodium nitrate and the phosphorus source monobasic potassium phosphate and calcium phosphate provided the best growth and sporulation of b. euphorbiae, but the others phosphorus source analyzed, except phosphoric acid, favored the fungus sporulation. the supplementation of the culture medium with peptone and yeast extract promoted a better growth and sporulation of the fungus and the addition of vitamins favored the production of conidia.
Phytotoxin produced by Bipolaris euphorbiae in-vitro is effective against the weed Euphorbia heterophylla
Barbosa, Aneli M.;Souza, Cristina G. M.;Dekker, Robert F. H.;Fonseca, Rafael C.;Ferreira, Dalva T.;
Brazilian Archives of Biology and Technology , 2002, DOI: 10.1590/S1516-89132002000200016
Abstract: four virulent strain isolates of the fungus, bipolaris euphorbiae (previously identified as a helminthosporium sp.), isolated from host plants in four states within brazil were screened for the production of phytotoxins that promoted wilting and defoliation of the brazilian weed, euphorbia heterophylla, commonly found growing among soyabean crops. only one isolate, b. euphorbiae strain i (euph petropar from mato grosso state), produced phytotoxin in-vitro when grown in stationary culture for 7 d at 28 ° c on minimum salts medium supplemented with 1.5 % glucose as the sole carbon source. phytotoxin was also produced when the fungal strain was grown on fructose, galactose, mannose, xylose and sucrose. the addition of nitrogen source (yeast extract, peptone or malt extract) to the culture medium did not influence phytotoxin production. the phytotoxin produced by strain i was most active at ph 6.0, stable between ph 3-9, and was highly thermostable, remaining fully active when heated at 90 ° c for 1 h.
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