Mauricio Paulo Batistella Pasini

Modelos de semivariogramas para estimar a densidade populacional da mosca‑do‑figo ao longo do ano

The objective of this work was to select semivariogram models to estimate the population density of fig fly (Zaprionus indianus; Diptera: Drosophilidae) throughout the year, using ordinary kriging. Nineteen monitoring sites were demarcated in an area of 8,200 m2, cropped with six fruit tree species: persimmon, citrus, fig, guava, apple, and peach. During a 24 month period, 106 weekly evaluations were done in these sites. The average number of adult fig flies captured weekly per trap, during each month, was subjected to the circular, spherical, pentaspherical, exponential, Gaussian, rational quadratic, hole effect, K-Bessel, J-Bessel, and stable semivariogram models, using ordinary kriging interpolation. The models with the best fit were selected by cross-validation. Each data set (months) has a particular spatial dependence structure, which makes it necessary to define specific models of semivariograms in order to enhance the adjustment to the experimental semivariogram. Therefore, it was not possible to determine a standard semivariogram model; instead, six theoretical models were selected: circular, Gaussian, hole effect, K-Bessel, J-Bessel, and stable.

Soluções atrativas para o monitoramento populacional de Zaprionus indianus (Diptera: Drosophilidae) em pomar de figo

The fig fly ( Zaprionus indianus ) is one of the major fig pests in Brazil, being its monitoring important for reducing the use of chemical insecticides. This study aimed at evaluating the efficiency of attractive food for Z. indianus , in fig orchard. The experiment was installed in a domestic fig (‘Roxo de Valinhos’ cultivar) orchard, using five treatments (fig juice at 50%, sugarcane molasses at 7% and grape juice at 30%, 40% and 50%), with five replicates, in a completely randomized design. A total of 3,284 adult fig flies (1,983 female and 1,301 male) were captured, representing 42% of the total insects and 62% of the drosophilids captured. The proportion of males and females was similar for all attractive solutions. Fig juice at 50% was effective in capturing the fig fly, being recommended for its monitoring in domestic orchards. Sugarcane molasses at 7%, despite its effectiveness, did not present regularity in fig fly capturing, being only indicated for periods of less than 28 days. At the concentrations tested, the grape juice was not effective.

Bioecologia de Oncideres cervina (Coleoptera: Cerambycidae) em Canela-Guaicá (Ocotea puberula: Lauraceae) na região central do Rio Grande do Sul, Brasil

The insect fauna knowledge of forest ecosystems have their importance in relation to damage caused by their different segments. The bioecology of the Oncideres cervina(Coleoptera: Cerambycidae) in Ocotea puberula(Lauraceae) was studied in the central region of Rio Grande do Sul state, Brazil. In 49 cut twigs were analyzed the cutoff frequency, the diameter of cut twigs and sections, twig length, posture incisions frequency, adult emergence, exit orifice size, length and volume of the larvae gallery of this species. The cut twigs period extends from February to March and this species is fit as thick cutter twigs. The incisions posture number is variable, but the highest concentration is found on sections 20 to 40 cm from the cut, with an average value of 11 incisions. Two hundred adults emerged from 27 twigs, with the most emergent on the first half of December. In order to complete its development, this species requires less wood volume if compared to other twig girdlers species.

Pentatomids associated with blackberry

Information concerning the presence of stink bugs in blackberry (Rubus spp.) in Brazil is sparse. This study aimed to identify the stink bug species associated with blackberry, to establish the daily dynamics and evaluate the fruits damage. The experiment was conducted in Santa Maria, Rio Grande do Sul State, Brazil, in blackberry orchard. Presence and evaluations of stink bugs were done weekly through visual and sweeping samplings at different day times. Five species of pentatomids were identified: Piezodorus guildinii, Nezara viridula, Euschistus heros, Dichelops furcatus and Edessa meditabunda. The bugs attack the drupelets producing a dark brown spot and wrinkled berries.