Management of whitefly this season will be challenging as a result of the high rainfall and flooding in November and again in February which has resulted in a wide spread of crop maturity both between and within each region. While some cotton crops will mature on time, others could be set back by as much as six weeks by the cool… Read more »
There have been several reports of GVB occurring in late cotton crops. This has led to some confusion in the industry as to whether GVB needs to be controlled at this late stage in cotton. Research done by DEEDI entomologists has shown that younger bolls are more susceptible to lint damage caused by GVB feeding. These factors need to be… Read more »
Broad mites have shown up in cotton crops in Emerald and in the Gwydir this season. Whilst the mites themselves are extremely small and difficult to see, even with a handlens, being familiar with symptoms of broad mite infestation may assist with a diagnosis.
Noticeable numbers of grass blue butterfly larvae (Zizina labradus) have been observed in young soybean crops in the Wide Bay Burnett. While the small green larvae (maximum length 10 mm) may be difficult to see in the crops, the damage they cause is very obvious. Grass blue butterfly larvae feeding results in windowing of the leaves (this is mostly cosmetic)… Read more »
There have been several reports of high numbers of apple dimpling bug (ADB) in early squaring cotton throughout the major cotton growing valleys. Also known as the yellow mirid, ADB adults (about 3mm long) are about one third the size of green mirid adults. They are yellow-green, have dark spines on the legs and hairy wings that are folded flat on… Read more »
As the earlier plantings of sorghum progress through flowering, moderate to high Helicoverpa pressure means that many crops have caterpillar numbers over threshold. Nucleopolyhedrovirus (NPV) is one of the main insecticides used to control Helicoverpa larvae in sorghum, however prevailing conditions play an important role in the speed and level of control achieved with NPV.
As the cotton season gets underway aphids are starting to be detected in crops, on ratoons, volunteers and weeds. Last season, there were some regions where Cotton Bunchy Top (CBT) was detected in crops towards the end of the season. To assess and manage the risk of yield loss caused by CBT, and minimise the difficulties of controlling insecticide resistant… Read more »
Dr Paul Grundy has joined the Field Crops Entomology team in Toowoomba as Senior Entomologist. Paul has moved to Toowoomba from Ayr where he was involved in evaluating the viability of cotton production in the Burdekin.
Last season was a somewhat low pressure year for silverleaf whitefly (SLW) in all cotton districts. The low pressure may have been attributed in part to high rainfall especially through central Queensland which does not favour whitefly population build up. St George and Mungindi districts still reached densities that exceeded the recommended insecticide spray thresholds although they generally fitted into… Read more »
As winter crops finish up and approach harvest, there are a couple of pests that still have the potential to cause some concerns. Armyworm and helicoverpa in barley, wheat and oats. There have been a number of reports of armyworm activity across the northern region in isolated pockets. Armyworm has the capacity to lop heads in barley, wheat and oats… Read more »
