101 resultados para Egg-laying dynamic

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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In Drosophila prosaltans reared on culture medium with caffeine (50-mu-g/ml, 100-mu-g/ml, 1000-mu-g/ml and 1500-mu-g/ml), fecundity decreased with increasing dosage. Other effects were (a) an approximately one day increase in development time of flies at 1000 and 1500-mu-g/ml, (b) a decrease of egg laying capacity, with increasing dosage and (c) a decrease of longevity when virgin males and females or mated males were analyzed. Mated treated females, however showed, in most experiments, greater longevity than the controls, thus suggesting a benefit of the partial blockage of reproduction caused by caffeine.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Three experiments were carried out to analyze the performance and egg quality of Japanese quails throughout the day when submitted to different lighting programs. In each experiment, birds were submitted to a period of 28 days for adaptation to the lighting program. During the following three days, each day - from 7 am to 7 pm or 9 pm - was divided into six or seven periods of two hours each, and the remaining hours corresponded to another single period. All birds were submitted to the same management practices, and received water and feed ad libitum. The experimental diet was formulated according to NRC (1994) standards. It was observed lower feed intake in the period of 9 pm to 7 am, and a higher incidence of lay from 3 pm to 7 pm, as opposite to hens, which peak of egg laying occurs during the morning. Some controversial results were found among experiments as to eggshell quality during the different periods of the day. Variation on the lighting program had little influence on the other performance and egg quality parameters.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Branches of coffee-plant were collected in Sao Sebastiao do Paraiso County, Minas Gerais State, at the Experimental Station of the Agricultural Research Company (Empresa de Pesquisa Agropecuaria de Minas Gerais - EPAMIG), with the aim of studying various aspects of oviposition by Quesada gigas (Hemiptera: Cicadidae). The number of branches with Q. gigas egg nests was analyzed, as well as the number of nests per branch, the eggs per nest and the diameter of the egg nest location on the branch. The preference for oviposition either on alive or dry branches and the size of the egg were assessed. Egg-laying occurred only on dry branches. The mean of the branch diameter on which the egg nests occurred was 2.5 +/- 0.53 mm. The number of eggs per nest averaged 13.2 +/- 4.9, and the number of egg nests per branch was 2.2 +/- 1.74. The eggs were 1.9 +/- 0.08 mm long by 0.5 +/- 0.04 mm wide. The largest diameters of the branches containing egg nests were found on the upper third of the trees, as well as the greatest amount of branches with egg nests, of egg nests per branch and of eggs per nest. The correlation relationship between all of the experiment variables was positive.

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The objective of this work was to evaluate the oviposition behavior of the whitefly Bemisia tabaci (Genn.) biotype B in relation to plant age, adult density and plant region on common beans plants. The genotype Perola was used to do the test. In free-choice tests 20, 30 and 40 day-old plants were used where evaluated the oviposition preference of the insect. In no-choice test, 30 day-old plants were used to evaluate densities of 50, 100 and 150 adults per plants. No-choice test for plant position (apex, median, base) 40 day-old plants were adopted for liberation of adults. The 30 and 40 day-old plants were preferred for oviposition, the densities of 100 adults per plants ensured the number of eggs enough to discriminate common beans genotypes with different whitefly resistance degrees, and apical region of plant were preferred for whitefly egg laying and therefore more suitable for egg sampling in common bean plants.

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Verificou-se o efeito de diferentes densidades de insetos por unidade de criação sobre o potencial reprodutivo de Chrysoperla externa. Utilizaram-se adultos da geração F4 mantidos a 25 ± 1ºC, 70 ± 10% de UR e fotofase de 12 horas. Foram utilizadas as seguintes densidades por unidade de criação (10 cm de diâmetro por 23 cm de altura e volume de 1650 cm³): um macho e três fêmeas, dois machos e seis fêmeas, três machos e nove fêmeas e quatro machos e doze fêmeas. Avaliou-se o período de pré-oviposição, a oviposição diária e total por fêmea e por unidade de criação, as porcentagens de ovos viáveis e inférteis e o índice de aproveitamento, calculado por fêmea e por unidade de criação. A densidade quatro machos e doze fêmeas apresentou melhor aproveitamento da unidade de criação, compensando as reduções observadas nos valores de postura média e total por fêmea.

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Orius insidiosus (SAY, 1832) is an important predator for biological pest control programs. The objective of this work was to evaluate the functional response, predation capacity and reproductive aspects of O. insidiosus when predating 1, 5, 10, 15, and 20 third/fourth instar nymphs of Aphis gossypii. The tests were conducted under laboratory conditions. Females of the predator were individually maintained in Petri dishes with a cotton leaf at each one of the aphid densities. The average rate of predation was of 0.93 [plus or minus] 0.13, 3.58 [plus or minus] 0.80, 7.31 [plus or minus] 1.45, 7.40 [plus or minus] 1.16, and 10.54 [plus or minus] 1.84 at the densities of 1, 5, 10, 15, and 20 aphids, respectively. The results showed an attack rate of 0.10 h-1 and 1.82 h of manipulation time. The predator spent 3.10 to 4.08 h feeding on leaf cotton glands; this behavior was not directly influenced by the prey density. The proportion of egg laying per female grew up to the density of 10 nymphs whereas the number of eggs per laying increased with the number of available preys.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The effect of four extracts from neem seeds (Azadirachta indica) containing 2000, 5000, 9000 and 10,000 ppm of azadirachtin A (AZA), quantified by high-performance liquid chromatography (HPLC) and diluted to 1.25%; 2.5%; 5.0%; 10.0% and 12.8% was verified by in vitro tests with engorged females and larvae of the cattle tick Rhipicephalus micro plus. The results from the bioassays with the engorged females showed that the main toxic effect of the extracts was reduction of the reproductive parameters, with a sharp drop in the number of eggs laid and the hatching rate, mainly when the extracts were diluted to 10.0% and 12.8%. The product effectiveness (PE) calculations for all the solutions tested showed that the AZA solution at 10,000 ppm (N10) was the most effective. However, statistical analysis of the PE data obtained for the proportional AZA concentrations in the different diluted extracts showed significance (P<0.05) of the effects included in the model (extract dilution, principle effect (classificatory) of the assay (extract) and the interaction between the two), indicating significant variations due to the dilution, the test and the interaction between the two factors in the tests with engorged females. For solutions N2, N5, and N9, it was not possible to estimate LC(90) values in the dilution range tested. The lowest LC(50) was observed for extract N5, and although extract N10 was the only extract for which the LC(90) could be estimated within the range tested, the LC(50) was higher than for N5 and N9. These results suggest that substances other than AZA present in the extracts influenced the efficacy, especially up to a certain LC range. In the tests with larvae, no mortality was observed, indicating zero effectiveness of all the extracts tested. The results of the tests with engorged females showed that the neem extracts had acaricide activity, inhibiting egg laying and the larval hatching rate. Complementary studies are necessary to develop new methods to isolate and/or identify other substances besides AZA contained in this plant, to enable using products made from it as acaricides. (C) 2011 Elsevier B.V. All rights reserved.