Determining the spatial distribution of the predatory ladybird Coccinella septempunctata using geostatistics in alfalfa fields in Dezful (Khuzestan) and Borujerd (Lorestan) Counties

Articles in Press

Document Type : Agricultural Entomology

Authors

1 Ph.D. student, Department of Plant Protection, College of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran

2 Department of Plant Protection, College of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran

3 associate professor

10.22092/jaep.2025.366601.1525

Abstract

Coccinella septempunctata is one of the most important natural enemies of alfalfa aphids. This research with the aim of investigating the geostatistical features of this ladybug species in alfalfa fields of Dezful and Borujerd cities, respectively, with an area of five and seven hectares (90 and 130 25x25 m grids). Sampling of ladybirds was peformed using a 1x1 m quadrat and two quadrats were randomly placed in each grid and the number of ladybirds inside each quadrat was counted and recorded by direct observation. Data analysis was done using GS+ and the variograms were calculated and presented by determination the model of spatial dependence changes with increasing distance between samples. The results of geostatistical analyzes for the above species showed that on 21 sampling datasets in Borujerd alfalfa field, 13 and eight data showed a better fit with exponential and spherical models, respectively. In Dezful, 16 data was better fitted with spherical model and five data with exponential model. The degree of spatial dependence varied between 0.521 and 0.999 and r2 varied between 0.52 and 0.99. The distribution pattern of this species is aggregative and the effective range for this species was between 94.6 and 481.8 m. The results of this research showed that the use of geostatistical methods, in addition to providing proper information on the ecology, distribution and its distribution of this species in the field, the possibility of using this method instead of dense sampling methods can make research projects much easier.

Keywords

Main Subjects

Applied Entomology and Phytopathology

Articles in Press, Corrected Proof
Available Online from 17 March 2025

Files

Share

How to cite

Statistics