Date of Award


Degree Type


Degree Name

Master of Science




Dr. Jeremy McNeil

Second Advisor

Dr. Bryan Neff

Third Advisor

Dr. Sheila Macfie


In late summer, diecious aphids, such as the potato aphid, Macrosiphum euphorbiae, move from their secondary summer host plants to primary ones when the sexual oviparae lay eggs that can survive winter conditions. I tested the hypothesis that primary host Rosacea sp, volatiles attract the gynoparae (the alate morph that produces oviparae), as well as males searching for suitable mates. In wind tunnel assays, both gynoparae and males oriented to and reached rose (Rosa rugosa) cuttings significantly more than to other odour sources including potato (Solarium tuberosum), a major secondary host. Volatiles from rose cuttings alone were as attractive to males as those with a calling virgin oviparous female. I also tested the hypothesis that the production of wings and mode of reproduction (asexual versus sexual) would be costly and be reflected in overall reproductive output. The fecundity of apterous and alate asexual and sexual morphs varied significantly. Those who produced wings and those involved in the switch from asexual to sexual reproduction being significantly lower than summer asexual individuals. These differences are discussed within the context of the tradeoff between movement and reproduction.



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