Examinando por Materia "Acari"

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    Acaricidal activity and repellency of Blechnum cordatum (Blechnaceae) against Tetranychus urticae (Acari: Tetranychidae).
    (Universidad del Valle, 2019-12-31) Hincapié, Carlos A.; Alarcón, Julio; Monsalve, Zulma I.; Céspedes, Carlos L.; Sociedad Colombiana de Entomología - Socolen; Universidad del Valle; Montoya Lerma, James
    Tetranychus urticae is a highly polyphagous mite species, with 1,140 host plant species reported worldwide. In this study, both Blechnum cordatum toxicity and repellent activity against T. urticae are reported. Regarding toxicity, the ethyl acetate fraction at 250 ppm and the n-hexane fractions at 250 ppm and 100 ppm caused the greatest accumulated mortality rate when application was made starting during the larval stage. Results showed that even at the lowest evaluated concentration (10 ppm), both fractions caused a significant decrease in the T. urticae population. The n-hexane fraction caused 100 % repellency at 50 ppm and repellency significantly superior to the control at 10 ppm. Relatively low activity was found when treatments were applied directly to adults. In addition, results suggest that the cumulative mortality could have been caused by starvation due to the observed repellency and the well-known deterrent activity of phytoecdysteroids (PEs) found in the extracts. Four PEs from the B. cordatum n-hexane fraction were isolated: ecdysone, ponasterone A, shidasterone and 2-deoxycrustecdysone.
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    PublicaciónAcceso abierto
    Fertility life tables of Raoiella indica (Trombidiformes: Tenuipalpidae) at different temperature and humidity levels.
    (Universidad del Valle, 2019-08-30) Martínez Mejía, David; Otero Colina, Gabriel; González Gómez, Rebeca; Pérez Panduro, Alejandro; Valle Mora, Javier; Sociedad Colombiana de Entomología - Socolen; Universidad del Valle
    A study of fertility life tables of Raoiella indica was carried out on coconut (Cocos nucifera) leaflets at controlled temperature and relative humidity (RH) in Texcoco, Mexico, with the objective of estimating the parameters of population increase of this mite. Cohorts of 12-hour-old Raoiella indica eggs were incubated at 22.5, 25, 27.5 or 30 °C and 40-50 % RH, as well as 27.5 °C with 30-40, 60-70 or 80-90 % RH. They were observed daily until the last mite died. Females that attained adulthood were provided with two males to promote mating and their oviposition was recorded daily. Each one-day-old male was put in contact with a female quiescent deutonymph daily to determine how many times a male could copulate after the deutonymph became an adult. With all temperatures and RH’s, mortality was evenly distributed throughout the observations. Developmental rate, reproduction, and, consequently, parameters of population increase were significantly associated with temperature. The highest rate of population increase took place at 27.5 °C and 40-40 RH. By itself, RH did not significantly affect those variables, although its extreme values showed slight negative effects. Approximately four females per male were observed. Males copulated with 4.56 females on average; this suggests that between 20 and 30 % of the males are enough to fertilize all females present.
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    PublicaciónAcceso abierto
    Mites associated with blackberry (Rubus sp. cv. Tupy) in two areas of Michoacan, México.
    (Universidad del Valle, 2019-12-31) Ayala Ortega, José de Jesús; Martínez Castillo, Ana Mabel; Pineda Guillermo, Samuel; Figueroa de la Rosa, José Isaac; Acuña Soto, Jesús; Ramos Lima, Mayra; Vargas Sandoval, Margarita; Sociedad Colombiana de Entomología - Socolen; Universidad del Valle; Montoya Lerma, James
    Damage caused by phytophagous mites is one of the main phytosanitary problems on blackberry crop. The mite species identification is a very significant activity to implement a program of integrated pest management. The aim of this study was to identify the species of phytophagous mites, predators, and other mites associated with blackberry crop in two locations of Michoacan, Mexico. The research was performed in two blackberry orchards located at Ziracuaretiro and Tacambaro municipalities, which had different type of management: conventional and non-conventional, respectively. In each orchard, 18 samples were collected at 15 d-intervals during an annual cycle, from June 2015 to May 2016. The collected mites were mounted in permanent slide for their taxonomic determination with specific keys with specific keys. Seventeen mite species belonging to ten families were identified, which six were phytophagous species, six were predatory, and five had varied habits. Six of the 17 taxa identified are new records of mites associated with blackberry crop. Most of the mites were collected in the conventional crop (65.4 %), while the abundance of predator mites was highest in the no-conventional crop.