Ph.D. / A number of aspects which might influence the buildup of spider mites on cotton were investigated. In contrast to their numbers on cotton treated with some of the insecticides used to control Heliothis arrniaer (Hübner) in field trials, the numbers of spider mites remained very low in the unsprayed cotton. Predators such as especially the pirate bug, Onus thniroborus (Hesse) appear to play an important role in maintaining mites in untreated plots at low population levels. Predator numbers were significantly reduced by some of the insecticides used. It is, however, not yet clear how the predator complex as a whole affects mite numbers ...
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:13989 |
| Date | 01 September 2015 |
| Creators | Botha, Johannes Hendrikus |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
| Rights | University of Johannesburg |
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