1:00 pm - 2:00 pm
318J Agriculture/Forestry Centre (AgFor), University of Alberta, Edmonton AB
A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES MSc Final Exam Seminar by Michelle Reid. This seminar is open to the general public to attend.
Thesis Topic: Monitoring insect diversity and parasitism levels in alfalfa seed production fields in western Canada
MSc with Dr. Boyd Mori
Alfalfa, Medicago sativa (L.) (Fabales: Fabaceae), is an excellent source of high protein feed for livestock. Canada is the second largest producer of alfalfa seed (4.2 M Kg/year) in the world, with the vast majority of production concentrated in the province of Alberta. The productivity of these fields is threatened by an invasive insect, the alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae) as well as a myriad of other potential insect pests. Recently, insecticide resistance was confirmed in several alfalfa weevil populations in Alberta, and few other management options exist. Many natural enemies of alfalfa insect pests are present in Alberta, including biological control agents of alfalfa weevil, Bathyplectes curculionis (Thomson) (Hymenoptera: Ichneumonidae) and Oomyzus incertus (Ratzeburg) (Hymenoptera: Eulophidae); however, the distribution of these species and their parasitism levels are currently unknown. Here, we assessed the current diversity and distribution of insects in alfalfa seed production fields, with special emphasis on parasitism levels of B. curculionis and O. incertus throughout southern Alberta. A survey was conducted to collect insects, including alfalfa weevil larvae, from seed production fields in 2020 and 2021. During this survey, insect collections were taken from fields at three crop stages: bud, flower and seed, these insects were sorted to guild (pest of alfalfa or natural enemy of pests) and identified to genus and species. Parasitism levels based on the multiplex PCR assay were comparable to live rearing and ranged from 0-90 % across sites. In addition, alfalfa weevil larval samples were collected throughout the growing season to assess the activity period of these parasitoids, finding parasitism activity throughout the month of June and into July. Assessing when and where these parasitoids occur, as well has how the two guilds interact will allow growers to better utilize these biological control agents and, ultimately, reduce spray applications.
Keywords: Agriculture, Alfalfa weevil, Multiplex PCR, Natural enemies, Seed alfalfa