Pest Management Science (2022) 78, 3596-3607
Samantha Elizabeth Ward, Paul A. Umina, Hazel Parry, Amber Balfour-Cunningham, Xuan Cheng, Thomas Heddle, Joanne C. Holloway, Caitlin Langley, Dustin Severtson, Maarten Van Helden and Ary A. Hoffmann (2022)
Is what you see what you get? The relationship between field observed and laboratory observed aphid parasitism rates in canola fields
Pest Management Science 78 (8), 3596-3607
Abstract:
Background
Estimating parasitoid abundance in the field can be difficult, even more so when attempting to quantify parasitism rates and the ecosystem service of biological control that parasitoids can provide. To understand how 'field observed' parasitism rates (in-field mummy counts) of the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae) translate to 'laboratory observed' parasitism rates (laboratory-reared parasitoid counts), field work was undertaken in Australian canola fields, over the winter growing season.
Results
Overall, laboratory observed parasitism was on average 2.4 times higher than field observed parasitism, with rates an average of four-fold higher in fields from South Australia. Total field observed and laboratory observed parasitism rates (OPRs) of M. persicae varied considerably across regions, but less so among fields within regions. As crop growth stage progressed, the incidence of field observed mummies increased. The incidence of total parasitoids reared also increased with crop growth stage, averaging 3.4% during flowering and reaching 14.4% during podding/senescing. Although there was a greater diversity of reared parasitoid species at later crop growth stages, the laboratory OPR was unaffected by parasitoid species. Diaeretiella rapae was the most commonly reared parasitoid, increasing in absolute abundance with crop growth stage.
Conclusion
These findings indicate that field mummy counts alone do not provide a clear representation of parasitism within canola fields.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Paul A. Umina, Hazel R. Parry, Maarten Van Helden, Ary A. Hoffmann
Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
surveys/distribution/isolation
