Emerging and vegetative summer crops in close proximity to unharvested winter crop are at risk of thrip damage, but the damage is largely cosmetic and rarely warrants treating. Thrips breed up in winter cereals, and particularly after rain, will move out of the winter crops in huge numbers. Most of you will be familiar with the joys of thrips biting… Read more »
Helicoverpa armigera active now. This spring a number of agronomists have just started monitoring pheromone traps across the northern region, and the results from the past two weeks illustrate how useful pheromone traps can be. Over the past 1-2 weeks, the traps are catching relatively high numbers of Helicoverpa armigera, and low catches of H. punctigera. In September it is generally assumed that… Read more »
Leaf mining caused by Agromyzid flies has recently been reported in wheat crops in the Goondiwindi/ Toobeah (late August) and Quirindi (late September) regions. Consultants reported their initial impression was that the damage symptoms, pale stripes on the leaves, resembled old stripe rust infections. However on closer inspection, the leaves were actually a windowed with frass visible inside the translucent… Read more »
As temperatures start to warm up there are a number of insect pests becoming active and causing crop damage. This post provides an overview of current and potential issues for field crops.
Armyworm in barley and wheat. A number of reports of armyworm in crops have been received over the past couple of weeks. Numbers range from 30 to 50 per square metre (extreme) to a more typical 5 to10 larvae per square metre. Assessing larval density is done using a sweep net, bucket or beating a section of row into a… Read more »
As the weather warms up aphid populations are becoming more obvious in crops. With aphid populations more visible in the crop, the key questions are whether they will impact on the yield of the crop, and whether it is necessary to control the aphids to avoid yield loss. Aphid infestations are widespread this year in both barley and wheat. In some instances,… Read more »
This winter we’ve seen several instances of severe scarab damage to winter cereals (wheat, barley and oats) , including on crops at Jandowae and Felton on the Darling Downs. The photograph below shows that severe damage is mostly confined to areas of paddocks which were previously pasture – and this is where the highest scarab populations were found.
Every year we receive reports of white heads in wheat, and while there are several possible causes of this symptom, one suspect implicated in the crime is a small stem boring larva called Ephysteris silignitis (Turner) belonging to the moth Family Gelechiidae.
The quick finish for winter cereals this season has resulted in the majority of crops escaping infestations of armyworm. Headers are already into some fields, but there are reports of armyworm making their presence felt in some of the later crops.
The most critical issues we face in managing cereal aphids currently is the lack of local knowledge about the likely impact of infestations on yield and quality (the damage thresholds). (http://thebeatsheet-ipmnews.blogspot.com/2008/09/cereal-aphids-in-wheat-and-barley.html).
