Biological control of pest Bruchidae may provide an important management strategy against infestation of stored grain legumes, a key source of dietary protein in developing countries. Previous related research has focused on the potential of parasitoids to control bruchids; the role of generalist predators in this application has not yet been extensively explored. / The anthocorid true bug Xylocoris flavipes (Reuter) exhibited a Type II density dependent functional response to five species of adult bruchids. The rate of kill of these large prey was quite low but fairly consistent and female predators were generally more effective. Of the species examined, only the eggs and neonate larvae of A. obtectus were accessible and predation on these stages was high. / Population interaction studies evaluating the effects of predator density and of time elapsed between infestation of commodity and predator addition indicated that adding the predator simultaneously with the pests significantly reduced the number of F$ sb1$, bruchid progeny for all species. Predator density contributed less to bruchid suppression than time of predator addition and bruchid progeny suppression was much greater than anticipated given the rate of kill observed in the functional response experiments. Reproduction by A. obtectus was almost entirely inhibited by the predator. / The high levels of suppression achieved with the predator indicated a significant biological control potential; however, the more fecund bruchid species with inaccessible immature stages continued to produce a large number of progeny. The predator was then combined with larval parasitoids capable of utilizing the internally-developing stages of the bruchids; bruchid suppression was considerably enhanced over the predator alone, and for the most fecund pests, suppression was greater than for the parasitoids alone.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.27414 |
| Date | January 1997 |
| Creators | Sing, Sharlene E. |
| Contributors | Stewart, R. K. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Natural Resource Sciences.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001571148, proquestno: MQ29789, Theses scanned by UMI/ProQuest. |
Page generated in 0.0017 seconds