| This thesis is an investigation of the colonization, fecundity, and probing behaviour of soybean aphid on soybean varieties that are resistant, suspected to be resistant, or susceptible. Initial screening of resistant, suspected resistant and susceptible soybean varieties indicated that aphid colonization varied by variety, with resistant and suspected resistant varieties having lower colonization ratings than the susceptible variety. Measurement of reproductive rates in non-choice tests showed lower reproductive rates on resistant varieties relative to susceptible varieties, suggesting that the mechanism of host plant resistance could be antibiosis. Aphid probing behaviour was not different among the varieties tested and no relationship was observed between probing behaviour and reproductive rate, further indicating that the mechanism of resistance could be antibiosis. Determining whether mechanism resistance is tolerance, antixenosis or antibiosis, as well as the specific modes of action are important factors in developing host plant resistance for economically important pests. |
