Biological control of twospotted spider mite, <Emphasis Type="Italic">Tetranychus urticae</Emphasis>, with predatory mite, <Emphasis Type="Italic">Neoseiulus californicus</Emphasis>, in strawberries |
| |
Authors: | Aimee B Fraulo Oscar E Liburd |
| |
Institution: | (1) Entomology and Nematology, University of Florida, Bldg. 970 Natural Area Dr., Gainesville, FL 32611, USA |
| |
Abstract: | Greenhouse and field experiments were conducted from 2005 to 2007 to determine the effectiveness of different release times
with the predatory mite, Neoseiulus californicus (McGregor), for control of the twospotted spider mite (TSSM), Tetranychus urticae Koch, in strawberries (Fragaria x ananassa Duchesne). The effect of N. californicus releases over time and on development of TSSM populations during a growing season were evaluated. Our hypothesis was that
repeated applications of N. californicus, which is currently recommended by biological control companies, might be unnecessary to attain season-long control of TSSM.
In greenhouse trials, three treatments consisting of releases of N. californicus at five-day intervals: day 0, day 5, and day 10, and an untreated control were evaluated. The treatment releases significantly
reduced TSSM below the control within five days of each release. Neoseiulus californicus significantly reduced TSSM in treatments with high densities (leaflets with ≥ 40 TSSM) below that of treatments with lower
densities (leaflets with ≤ 10 TSSM) demonstrating that if released at a predator: prey ratio of 1:10, timing of release does
not alter the effectiveness of N. californicus in controlling TSSM. However, we found that if the ratio of predator: prey remains adequate, N. californicus is a more efficient predator at high TSSM densities. Field studies included three treatments consisting of releases of N. californicus at one-month intervals. All treatments significantly reduced TSSM compared with the control plots (no releases). Releases
applied early in the season sustained TSSM significantly below those in the control plots for the whole season. Our results
indicate that one release of N. californicus is able to sustained control of TSSM in strawberry throughout a growing season if released when TSSM populations are low
early in the season in the southeastern United States. |
| |
Keywords: | Prey density Predatory mites Control costs Timed releases Southeastern United States |
本文献已被 PubMed SpringerLink 等数据库收录! |
|