Significant soybean aphid (Aphis glycines) populations have now been observed in many coastal soybean crops. Once the crop approaches late flowering, a spray decision must be made as later aphid infestations can severely delay harvest maturity. Careful monitoring is required to determine if populations are trending upwards to and beyond threshold levels, or if the aphids are being contained by… Read more »
A major outbreak of grass blue butterfly (GBB) (Zizina labradus) in late vegetative and flowering soybeans has been reported in the Maryborough/Hervey Bay region. Some crops inspected had 10-12 GBB larvae per square metre with many plants denuded of buds and flowers. Other crops had less damage and fewer larvae (4-5 per square metre), but had 5 or more adult butterflies… Read more »
UPDATE: Crop progress report (March 2018) Recent photos of the crop where a stem fly infestation was reported in early February show signs of stem fly pupation, but no crop stress symptoms (i.e. no yellow and dying leaves), indicating that managing the outbreak when it was first detected would have been a waste of time and money (assuming there will… Read more »
Major soybean moth outbreaks have recently been reported in some coastal Burnett soybean crops, and lesser outbreaks in crops in the Burdekin. Soybean moth is generally a minor soybean pest but major outbreaks have been reported periodically in all soybean growing regions. In extreme cases, crops can be totally defoliated. Feeding damage Larvae feed mostly within the leaves, making distinctive… Read more »
A devastating disease was observed in several paddocks of soybean crops in the Branchview area of the Darling Downs in late autumn 2016. Almost 100 percent of plants were affected in some paddocks. The affected plants produced no, or very few filled pods and instead had a proliferation of tiny immature pods as shown in Photos 1 and 2. The plants… Read more »
Once again, lucerne crown borer (LCB) (Zygrita diva) has been active in soybeans this season. Worst affected regions were the Northern Rivers and the Liverpool Plains in NSW, but reports were also fielded from the Bundaberg, Fassifern and Darling Downs regions in Queensland. In some of the severely affected crops, over 80% of plants were infested, and up to 70%… Read more »
There is an understandable level of concern about how best to manage etiella (Etiella behrii) in summer mungbean crops following the unexpectedly high etiella infestations (and corresponding seed damage and contamination) in spring mungbean crops on the Downs and in Central Queensland and North Western New South Wales. Responding to the etiella threat without reacting prematurely and creating more pest… Read more »
Significant soybean moth activity has recently been reported in some Burdekin soybean crops. Soybean moth is a generally a minor soybean pest but significant outbreaks have been reported periodically in all soybean growing regions. Feeding damage Larvae feed mostly within the leaves, making distinctive pale leaf mines, and often distorting leaves. Soybean moth is present in low numbers in most… Read more »
Lucerne crown borer (Zygrita diva) (LCB) is causing severe damage in a number of soybean crops in the Bundaberg region of SE Qld, and on the North Coast region of NSW. In some cases up to 75% of plants are infested and early plant death is evident. Damage seems to be worse in the early (November-planted) crops which were sown… Read more »
The 2013/14 soybean growing season has been challenging for many growers with very low rainfall and high temperatures until late March. Crop stress was sometimes wrongly attributed to insect pests although a number of crops were infested with more unusual pests such as etiella. The high temperatures also increased the impact of lucerne crown borer in infested crops.
