Assessing the impact of site-specific spraying on control of Eurygaster integriceps (Hemiptera: Scutelleridae) damage and natural enemies

Abstract

Sunn pest, Eurygaster integriceps Puton is a key pest of wheat and barley in Iran. In this study, the impact of site-specific spraying on control of sunn pest damage and densities of the natural enemies was compared with the whole-field spraying method in 2009 and 2010. Three plots were assigned to each spraying method and two others were left untreated as control. The plots were divided into 11 9 11 m grids. Adults of E. integriceps were sampled using the distance-walk method. Coccinellids, Chrysoperla carnea and nymphs of sunn pest were sampled using a sweep net. Spatial analysis of datasets was done using Geostatistical Analyst extension of ArcGIS 9.3. The spatial analysis indicated that the adults and nymphs of E. integriceps had aggregated distribution in space and that site-specific spraying was applicable. Whole-field spraying was carried out when the mean density of E. integriceps in plots exceeded the economic threshold. In the site-specific spraying method, decamethrin ([cyano-[3-(phenoxy) phenyl] methyl] 3-(2,2-dibromoethenyl)-2,2-dimethylcyclopropane-1-carboxylate) was applied to the grid cells with densities above the economic threshold. Site-specific application reduced the insecticide input by ca. 40-50%. The numbers of C. carnea and coccinellids were higher in site-specifically sprayed plots compared with whole-sprayed plots after treatment. The mean numbers of nymphs were not significantly different (P \ 0.01) in whole-field and site-specifically sprayed plots. Percent damaged grain was below the economic damage threshold in all treated plots. It can be concluded that site-specific spraying has the potential to control E. integriceps at an acceptable level along with reducing the amount of insecticide used. It also conserved natural enemies in untreated refuges.

Geostatistical tools for the study of insect spatial distribution: practical implications in the integrated management of orchard and vineyard pests

“…After the first studies carried out in North America to investigate the distribution of Pectinophora gossypiella (Saunders) in cotton, L. hesperus in lentil fields, and grasshoppers in uncultivated areas (Borth & Huber 1987;Kemp et al 1989;Schotzko & O'Keefee 1989), geostatistics have seen many applications in various fields of crop protection against worms or arthropods pests (for more details see Liebhold et al 1993;Brenner et al 1998;Arbogast et al 2000;Brandhorst-Hubbard et al 2001;Park et al 2007;Sciarretta & Trematerra 2009;Webster 2010) and, in a few cases, to highlight predator and parasitoid distribution (Karimzadeh et al 2011;Perović & Gurr 2012).…”

Distribuição espacial de Rhynchophorus palmarum em palma de óleo no Estado do Pará, Amazônia

“…Já o alcance máximo foi de 710 metros com área de influência de 158,4 ha, podendo desta forma, considerar que o R. palmarum, possui uma grande área de influência . O que não foi observado por Karimzadeh et al (2011), que ao avaliarem a distribuição espaço temporal de Eurygaster integriceps Puton, limite do plantio com a floresta, sendo esta, separada por uma estrada utilizada para escoar a produção (Figura 4).…”

Sensor‐Based Insecticide Spraying to Control Cereal Aphids and Preserve Lady Beetles

“…If a sensor is unavailable to the farmer, then switching the sprayer completely off should be considered, especially in low biomass areas. Karimzadeh et al (2011) tested a mapping approach (working steps: first, pest observation and second, spraying according to a spraying map) for controlling sunn pests ( Eurygaster integriceps ) in wheat fields in Iran. These authors switched the sprayer off if the mean density of this pest was below a certain threshold.…”