Effect of soybean cultivar on life history parameters of Tetranychus urticae Koch (Acari: Tetranychidae)

Abstract

The two-spotted spider mite, Tetranychus urticae Koch, is a very polyphagous pest with a worldwide distribution. In order to appraise population growth parameters of this pest, samples of two-spotted spider mites were taken from soybean (Glycine max) fields of Moghan region, Iran in June 2007 and are reared on bean plants var. Derakhshan (Phaseolus vulgaris) in a growth chamber. The life table parameters of this pest were calculated on three commercial soybean cultivars (Zane, Hach, and L17) and one hybrid (Hob 9 Will) at 25 ± 1°C, 60 ± 10%RH, and 16 h photophase. The developmental times of immature stages varied from 9.69 on Hach to 9.82 days on L17, whereas the immature survival was 57-79% on Hach and Hob 9 Will, respectively. On average, there were 65.5, 40.8, 38.8 and 34 eggs produced per female on L17, Hach, Hob 9 Will and Zane, respectively. The intrinsic rate of natural increase (r m ) for T. urticae on Hob 9 Will was the highest, whereas the values for r m ranged from 0.211 (females/female/day) on Zane to 0.292 on Hob 9 Will. Also, jackknife values of other life table parameters such as net reproductive rate (R 0 ), generation times (T), doubling time (DT), and finite rate of increase (k) on these cultivars were estimated. Overall, the two-spotted spider mite indicated a better performance on Hob 9 Will than on the other soybean cultivars.

Performance of corn leaf aphid, Rhopalosiphum maidis (Fitch) (Homoptera: Aphididae) on selected maize hybrids under laboratory conditions

“…Before using the leaves in the experiments, they were checked and cleaned of aphids and other pests if required. We replaced the excised leaves every 4-5 days with fresh corn leaves as described previously (Kuo et al, 2006;Razmjou et al, 2009). …”

Citrus rootstocks influence the population densities of pest mites

“…Citrus rust mite is a key pest in the main citrus producing regions of Brazil and its attack may lead to yield losses as well as aesthetic changes in fruit appearance and reduction in total soluble solids (CHIARADIA, 2001;MORAES & FLECHTMANN, 2008;MENDONÇA & SILVA, 2009). The mite T. mexicanus is a leaf pest of several crops including citrus (PRITCHARD & BAKER, 1955;QUIROS-GONZALEZ, 2000;RAZMJOU et al, 2009;VACANTE, 2010).…”

Incidence of Tetranychus urticae Koch on brinjal under field and screen house conditions

“…Host plant species often differ in chemical profiles, thereby affecting host (i.e., herbivore) quality [14]. Many authors have reported on the involvement of secondary metabolites in the interaction between plants and herbivorous pests.…”