Predatory Insects in Saskatchewan Farming Systems
| dc.contributor.advisor | Olfert, O. | |
| dc.contributor.advisor | Gillott, C. | |
| dc.creator | Melnychuk, Nancy A | |
| dc.date.accessioned | 2024-01-24T21:11:58Z | |
| dc.date.available | 2024-01-24T21:11:58Z | |
| dc.date.issued | 1999 | |
| dc.date.submitted | 1999 | |
| dc.description.abstract | This study was designed to examine the effect of cropping systems and agrochemical input systems on the predatory insect fauna within four Saskatchewan farming systems. Two cropping systems, wheat-wheat-fallow and diversified grain-forage and two input systems, high level and organic, were examined. Pitfall traps were used to collect the ground-dwelling predatory insects and sweep nets were used to collect the predatory insects present in the crop foliage. Eight fields were sampled three times during the summer (June/July/August) and the study was replicated over 3 years (1994 -1996). A total of 2,076 ground-dwelling predators representing thirty eight genera and 1,704 foliar-dwelling predators representing eight different genera were collected over the duration of the study. The collection was dominated by five genera of ground-dwelling predators (Carabidae: Bembidion, Amara, Agonum, Harpalus, Pterostichus) and two genera of foliar predators (Anthocoridae: Orius; Nabidae: Nabis). Abundance, richness (Menhinick index) and dominance (Berger-Parker index) of the predatory insect fauna were analysed using a split-plot analysis of variance model with years as the replicate, sample date as the main plot effect, and farm site as the sub-plot effect. Comparisons were made between the diversified grain-forage and wheat-wheat-fallow cropping systems (n= 4 farms) and the organic and high input systems (n=4 farms) using linear contrasts. The results showed that cropping system had the greatest influence on the abundance and diversity of the predatory insect fauna. The wheat-wheat-fallow system was found to have a significantly higher abundance and diversity of the ground-dwelling predators while the diversified grain-forage system had a higher abundance and diversity of foliar-dwelling predators. No clear differences were observed between the two input systems. | |
| dc.identifier.uri | https://hdl.handle.net/10388/15455 | |
| dc.title | Predatory Insects in Saskatchewan Farming Systems | |
| dc.type.genre | Thesis | |
| thesis.degree.department | Graduate Studies and Research | |
| thesis.degree.discipline | Biology | |
| thesis.degree.grantor | University of Saskatchewan | en_US |
| thesis.degree.level | Masters | |
| thesis.degree.name | Master of Science (M.Sc.) |