The spatio-temporal pattern of Delphacodes kuscheli (Homoptera: Delphacidae) abundance in central Argentina
Autor: | D. E. Gorla, Mariano P. Grilli |
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Rok vydání: | 1997 |
Předmět: |
Maize rough dwarf virus
education.field_of_study biology Ecology Homoptera Population Sampling (statistics) General Medicine biology.organism_classification Population density Normalized Difference Vegetation Index Abundance (ecology) Insect Science Physical geography education Transect Agronomy and Crop Science |
Zdroj: | Bulletin of Entomological Research. 87:45-53 |
ISSN: | 1475-2670 0007-4853 |
DOI: | 10.1017/s0007485300036348 |
Popis: | Delphacodes kuscheli Fennah is the vector of maize rough dwarf virus, that affects maize production in central Argentina. The spatial and temporal abundance pattern of the insect vector was studied from October 1992 to November 1994, within endemic and non-endemic areas of the crop disease. Insect density was estimated every 7–15 days during spring and summer (maize season) or monthly during autumn and winter from high (6 m) and low (1.5 m) sticky traps placed at eight sampling stations along a 300 km transect. Each year, D. kuscheli density increased from October, peaked in December, to decrease afterwards and disappear in May. Density was lower in the nonendemic area and higher in the endemic one. The average absolute difference of density between sampling station pairs increased with the distance between the sampling stations (R2=0.85), and the correlation of density changes decreased with the distance between the sampling stations (R2=0.78), suggesting that the population dynamics were affected more by local than by regional factors. There was a significant correlation (with a 36 days lag) between the normalized difference vegetation index (NDVI) (calculated from 15 days maximum value composites images of NOAA-11 meteorological satellites) and D. kuscheli abundance. Based on this regression model, and using the time series of the satellite derived NDVI values, maps of the distribution and abundance of D. kuscheli within the study area for the spring and summer of 1992 were produced. |
Databáze: | OpenAIRE |
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