Improved management of Rutherglen bug in the Northern Region

by Hazel Parry

GRDC project code CSP2104-007RTX

Please click here to access the Rutherglen bug population projection dashboard.

Check out our recent GRDC Update Paper from the Goondiwindi Grains Research Update (30-31 July 2024).  You can download our recent (October 2023) research finding information handouts, which include information on identification, habitat, risk forecasting and management or listen to a January 2024 GRDC podcast on Rutherglen bug: risk forecasting and management.  If you’d like to learn more about the project, and how to successfully identify Rutherglen bug in the field, check out the embedded video below.

Rutherglen bug Nysius vinitor (Hemiptera: Orsillidae) is a small, fast-moving bug that builds up to high numbers during the warmer months.  If it gathers on seedlings, the feeding can result in plant dehydration and death.  At harvest, seed damage and contamination can lead to economic losses.  The sudden appearance of this pest is problematic, but very little is currently known about the landscape ecology of this pest besides that it can be found on a wide variety of plant hosts (including many weed species).

This project is funded by the Grains Research and Development Corporation (GRDC) and is a collaboration between CSIRO, UQ and DRNSW. It commenced in July 2021 and will run until June 2024.  During this project, the researchers are focused on understanding how Rutherglen bug populations may persist in the local environment or why they might suddenly appear in crops, updating management guidelines to minimise the effects of early- and late-season infestations, and providing a risk framework to predict likely infestation from both locally emerged and migratory populations.

So far, our results have surprised us: our samples in canola and summer grains crops as well as weeds across northern NSW were overwhelmingly dominated by Nysius caledoniae (Grey Cluster Bug) in the first year of our project – a taxonomically very similar but genetically distinct species, not currently considered to be a significant pest in grains.  This has given us pause to consider that we really are looking at a complex of two species found throughout our grain cropping regions, and the dynamics between these species is likely much more important than previously considered.  Despite finding Rutherglen bugs in high numbers early in the season and in canola regrowth, they were not identified as a pest issue at any of the inspected sites (and neither was the generally more dominant Grey Cluster bug).

In the second year of our project we found Rutherglen bug present in higher numbers, and a few instances where a pest issue was identified in sorghum crops at a couple of sites in the Moree region.  However, in general, populations were still relatively low and certainly not ‘outbreaks’.

Learn more about the project and how to identify Rutherglen Bug in this recent GRDC video.

Links to extra information:

Parry, H. R., Marcora, A., Macfadyen, S., Hopkinson, J., Hulthen, A. D., Neave, M., Bianchi, F. J. J. A., Franzmann, B. A., Lloyd, R. J., Miles, M., Zalucki, M. P., and Schellhorn, N. A. 2019, A native with a taste for the exotic: weeds and pasture provide year‐round habitat for Nysius vinitor (Hemiptera: Orsillidae) across Australia, with implications for area‐wide management. Austral Entomology, 58: 237– 247. https://doi.org/10.1111/aen.12391

Moradi‐Vajargah, M., and Parry, H. R. 2017, Environmental and biological drivers of flight initiation in a sporadic pest, Rutherglen bug, Nysius vinitor Bergroth (Hemiptera: Orsillidae). Austral Entomology, 56: 225– 234. https://doi.org/10.1111/aen.12225