Maria Elisa de Sena Fernandes

Novos acessos de tomateiro resistentes à mosca-branca biótipo B

O objetivo deste trabalho foi selecionar novas fontes de resistencia a Bemisiaxa0tabaci biotipo B, entre 34 acessos de tomateiro ( Lycopersicon esculentum ), do Banco de Germoplasma de Hortalicas da UFV. Avaliaram-se os numeros de adultos, ovos e ninfas por planta, alem da densidade de tricomas. Detectaram-se diferencas entre os acessos nas variaveis avaliadas. Osxa0acessos BGH-166, BGH-616, BGH-850, BGH-990, BGH-2102 e BGH-2125 apresentaram menor numero de adultos, ovos e ninfas por planta e tiveram menor densidade de tricomas. A resistencia dos acessos de tomate a mosca-branca foi associada a uma menor densidade de tricomas.

Induced responses of Coffea arabica to attack of Coccus viridis stimulate locomotion of the herbivore

The green scale, Coccus viridis (Green) (Hemiptera: Coccidae), is an insect pest of coffee and several other perennial cultivated plant species. We investigated changes in alkaloid and phenolic contents in coffee plants as a response to herbivory by this insect. Greenhouse‐grown, 11‐month‐old coffee plants were artificially infested with the coccid and compared with control, uninfested plants. Leaf samples were taken at 15, 30, 45, and 60u2003days after infestation, and high‐performance liquid chromatography was used to identify and quantify alkaloid and phenolic compounds induced by the coccids at each sampling date. Of the compounds investigated, caffeine was the main coffee alkaloid detected in fully developed leaves, and its concentration in infested plants was twice as high as in the control plants. The main coffee phenolics were caffeic and chlorogenic acid, and a significant increase in their concentrations occurred only in plants infested by C. viridis. A positive and significant relationship was found between alkaloid and phenolic concentrations and the infestation level by adults and nymphs of C. viridis. Caffeine and chlorogenic acid applied on coffee leaves stimulated the locomotory activity of the green scale, thus reducing their feeding compared to untreated leaves. This is the first study to show increased levels of coffee alkaloids and phenolics in response to herbivory by scale insects. The elevation of caffeine and chlorogenic acid levels in coffee leaves because of C. viridis infestation seems to affect this generalist insect by stimulating the locomotion of crawlers.

Tomato plant inheritance of antixenotic resistance to tomato leafminer

The objective of this work was to determine the inheritance of resistance by antixenosis in tomato plants (Lycopersicon esculentum) to tomato leafminer (Tuta absoluta (Lepidoptera: Gelechiidae)). Evaluations were performed for tomato plants of the generations P1, P2, F1, F2, RC1 and RC2. The measured characteristic in the parents, BGH-1497 (P2 male) and Santa Clara (P1 female), and in the F1, F2, RC1 and RC2 generations was the number of eggs per plant. This number was converted to the oviposition nonpreference index. The inheritance of antixenosis resistance of genotype BGH-1497 is ruled by a gene of greater effect and polygenes in epistatic interactions, with a phenotypic proportion of 13:3 between susceptible and resistant genotypes, respectively.

Trichomes and hydrocarbons associated with the tomato plant antixenosis to the leafminer

The objective of this work was to study the density of trichomes and hydrocarbons associated with the resistance by antixenosis of 42 subsamples of tomato plants from the Horticultural Germplasm Bank of the Universidade Federal de Viçosa (HGB-UFV) to Liriomyza trifolii. These subsamples were studied in addition to Santa Clara cultivar, which was used as a standard of susceptibility to leafminers. The evaluated characteristics were the number of mined leaflets per plant, mines per plant, trichome density and chemical compounds in the leaves. Differences were detected among the subsamples in the variables studied. We identified 20 peaks in the chromatograms of leaf hexane extract the subsamples tested. The subsamples HGBs - 216, 813, 985, 987, 991, 992, 993, 1532, 1989, 1991, 2048, 2055, 2064, 2068, 2073, 2075, 2089, 2096 and 2097 were selected as sources of resistance to L. trifolii. The resistance mechanism associated to these subsamples was antixenosis. In addition, the low density of trichomes and the chemical compounds in the subsamples can be possible causes of pest resistance.

Controle massal da broca-do-café com armadilhas de garrafa Pet vermelha em cafeeiro

The objective of this work was to evaluate the efficacy of red PET-bottle traps, containing attractive alcoholic volatile compounds, in the mass control of coffee berry borer (Hypothenemus hampei). The evaluations were carried out in four coffee crops, during two years. Nine hundred PET-bottle traps, painted red, were distributed in three of the four coffee crops; one crop without traps was used as a control. Holes drilled into berries (%) were determined in these crops. There was a reduction in drilled berries in crops with traps, from the 2007/2008 harvest to the 2008/2009 harvest. The highest coffee berry borer densities in traps was observed in the flowering and small-green berries stages. The red PET-bottle trap is efficient in the mass control of the coffee berry borer population, since it reduces the percentage of drilled berries in 57%; however, this reduction is not enough to keep borer densities below the control level.

A low-cost trap for Cerambycidae monitoring in forest plantations in Brazil

The objective of this work was to evaluate the use of a low-cost trap to capture Cerambycidae in different seasons in planted forests in Brazil. Thirty polyethylene-terephthalate trap bottles per hectare were used, disposed at every 50 m. The traps were red painted and contained glass flasks with a mixture of ethanol, methanol and benzaldehyde. There were soap and water at the trap bottom. The traps were checked biweekly for beetle presence. Sampling time required one minute per sample, and traps were easy to use. Total sampling cost, including materials and labor, was US

Ocorrência e distribuição espacial e temporal do coleóptero Naupactus curtus em cafeeiros de Minas Gerais, Brasil

13.46 per sample. Six Cerambycidae species were captured along the dry and rainy seasons.

Flight movement and spatial distribution of immunomarked thrips in onion, potato, and tomato

There were no reports of Naupactus curtus in Minas Gerais, and the few occurrences in other Brazilian States bring is little of information about its spatial distribution on coffee plants. This work aimed to report the occurrence of this potential in Minas Gerais and study its their spatial and temporal distribution dynamics on crops of Coffea arabica. The study was conducted in coffee plants in Ponte Nova and Jaboticatubas, with the evaluation of density being monthly. N. curtus was found in two areas in Minas Gerais, presenting higher densities at the edges of the crops.

Impact and Selectivity of Insecticides to Predators and Parasitoids

The objective of this work was to evaluate the spatial distribution of thrips in different crops, and the correlation between meterological parameters and the flight movements of this pest, using immunomarking. The experiment was conducted in cultivated areas, withxa0 tomato ( Solanum lycopersicum ), potato ( Solanum tuberosum ), and onion ( Allium cepa ); and non‑cultivated areas, with weedy plants. The areas with tomato (100xa0days), potato (20xa0days), and weeds were sprayed with casein, albumin, and soy milk, respectively, to mark adult thrips; however, the areas with onion (50xa0days) and tomato (10xa0days) were not sprayed. Thrips were captured with georeferenced blue sticky traps, transferred into tubes, and identified by treatment area with the Elisa test. The dependence between the samples and the capture distance was determined using geostatistics. Meteorlogical parameters were correlated with thrips density in each area. The three protein types used for immunomarking were detected in different proportions in the thrips. There was a correlation between casein‑marked thrips and wind speed. The thrips flew a maximum distance of 3.5xa0km and dispersed from the older (tomato) to the younger crops (potato). The immunomarking method is efficient to mark large quantities of thrips.