The probability distribution of the orthezia scale, Orthezia praelonga Douglas, was studied in plots of commercial orange orchards (Citrus sinensis L., var. "Pêra Rio"), with 5, 9 and 15 years of age, during one year. The survey of presence or absence of the pest in the plants was carried through twenty samplings in the total area of each plot visually inspecting each plant. The dispersion indexes used were: variance/mean relationship (I), index of Morisita (Id), coefficient of Green (Cx) and k exponent of negative binomial distribution for each sampling. The negative binomial distribution was more representative of the frequency distribution data of this scale in citrus, since the variance was superior to the average in all samplings. The analysis of the aggregation index showed that the majority of the samplings presented aggregate distribution for the scales.
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http://dx.doi.org/10.1590/s1519-566x2006000300016 | DOI Listing |
Protoplasma
September 2019
Department of Developmental Biology and Morphology of Invertebrates, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland.
The biological nature, ultrastructure, distribution, and mode of transmission between generations of the microorganisms associated with three species (Orthezia urticae, Matsucoccus pini, Steingelia gorodetskia) of primitive families (archaeococcoids = Orthezioidea) of scale insects were investigated by means of microscopic and molecular methods. In all the specimens of Orthezia urticae and Matsucoccus pini examined, bacteria Wolbachia were identified. In some examined specimens of O.
View Article and Find Full Text PDFJ Insect Sci
August 2009
Department of Plant and Soil Science, Entomology Research Laboratory, The University of Vermont, Burlington, VT 05405-0105, USA.
A fungal epizootic in populations of Fiorinia externa Ferris (Hemiptera: Diaspididae) infesting hemlock trees, Tsuga canadensis (L.) Carrière (Pinales: Pinaceae) in forests of the Northeastern US has been recently detected. The current known distribution of the epizootic spans 36 sites in New York, Pennsylvania, New Jersey and Connecticut.
View Article and Find Full Text PDFNeotrop Entomol
October 2008
Depto. Fitossanidade, FCAV, UNESP, Jaboticabal, SP, 14.884-900.
The probability distribution of the orthezia scale, Orthezia praelonga Douglas, was studied in plots of commercial orange orchards (Citrus sinensis L., var. "Pêra Rio"), with 5, 9 and 15 years of age, during one year.
View Article and Find Full Text PDFNeotrop Entomol
June 2008
Depto Fitossanidade, FCAV, FCAV, UNESP, Jaboticabal, SP, Brazil.
The sequential sampling is characterized by using samples of variable sizes, and has the advantage of reducing sampling time and costs if compared to fixed-size sampling. To introduce an adequate management for orthezia, sequential sampling plans were developed for orchards under low and high infestation. Data were collected in Matão, SP, in commercial stands of the orange variety 'Pêra Rio', at five, nine and 15 years of age.
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