POPULATION DYNAMICS OF THE PHYTOPHAGOUS PESTS INFESTING TWO BROAD BEAN CULTIVARS ALONG WITH THEIR PREDATORY PHYTOSEIID MITES TYPHLODROMPIS Swiriskii (ATHIAS-HENRIOT) AT BEHEIRA GOVERNORATE.

Abstract

This study was conducted to determine the levels of infestation of two broad bean (Vicia faba) varieties with Tetranychus urticaeand its predatory phytoseiid mite, Typhlodrompis swiriskii (Athias-Henriot) and some insect pests. The study was investigated the population density of two spotted spider mite Tetranychus urticaein Beheira Governorate, Egypt, during 2010-2012 on two cultivars of broad bean, Sakha1 and Sakha3. Our results showed that the infestation of two cultivars by T. urticae was early started in 21 December) then, gradually increased and to reach their peaks during March for the two cultivars. The infestation by T. urticae during the first season was started in late December in Sakha1 cultivar only, while in Sakha3 was firstly recorded during first June 2012. The infestation was slightly increased to reach their peak during 3rd of March on the two cultivars. On the other hand, mite infestation was gradually increased reaching their peaks on March 17th for Sakhe 3. At the late season, specifically in April, the numbers of T. urticae stages decreased gradually on the two Broadbean cultivars. The predatory mite, Typhlodrompis swerskii was firstly recorded at the beginning of January for the two tested cultivars in the two successive seasons. Both population declined at the beginning April (include dates or use months only- to be consistent). The Sakha3 cultivar was more infested with higher population of predatory mites, than Sakha1. Also, the study showed the presence of the? two phytophagous insect species, Aphids gossypi and Thrips tabaci in moderated number on the two-tested broad bean. The infestation by Phytophagous insects were started in the third week of December 2010 and increased then by the first week of January then decreased gradually for the A. gossypi from the mid of February, while it was increased for the T. tabaci from mid of Feb. to the end of April. The infestation of A. gossypi and T. tabaci for the two cultivars at the second season started at the last week of December and increased by the end of January then decreased gradually. Next they started to increase before the first week of March for both the two insects on Saka3 cultivar.