Spatio‐temporal association of Therioaphis maculata and Hippodamia variegata in alfalfa fields

• Published in: Agricultural and forest entomology Vol. 19; no. 1; pp. 81 - 92
• Main Authors: Shayestehmehr, Hakimeh, Karimzadeh, Roghaiyeh, Hejazi, Mir J.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.02.2017
• Subjects: Aphididae; Coccinellidae; Coleoptera; Crops; Entomology; Hemiptera; Hippodamia variegata; Pest control; Prey–predator dynamics; SADIE; spatial distribution; spotted alfalfa aphid; Therioaphis maculata
• ISSN: 1461-9555; 1461-9563
• DOI: 10.1111/afe.12183

A 2‐year study was conducted aiming to characterize the spatio‐temporal association of spotted alfalfa aphid Therioaphis maculata Buckten (Hemiptera: Aphididae) and Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae) in alfalfa fields. The present study was conducted in 0.5‐, 3.1‐ and 7.3‐ha alfalfa fields and at two spatial scales. The 0.5‐ha field was divided into 10 × 10 m grid; and the 3.1‐ and 7.3‐ha fields were divided into 30 × 30 m grids. Weekly samplings began when plant height reached approximately 15 cm and were continued until hay cutting. Forty and ten stems were chosen randomly in 30 × 30 m and 10 × 10 m grids, respectively. The stems were shaken into a white pan three times and the aphids and coccinellids fallen in the pan were counted. The data were analyzed using spatial analysis by distance indices. Both T. maculata and H. variegata showed aggregative spatial pattern. The results also revealed that there was a positive spatial association between spotted alfalfa aphids and lady beetles. Spatio‐temporal synchrony between predator and prey distribution is important with respect to implementing biological control. Therefore, the findings of the present study can be used in the conservation of natural enemies, site‐specific spraying against spotted alfalfa aphid and the effective management of this pest.