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.
As the warm weather persists, insect activity is remaining high. DAFFQ Entomology has received numerous reports of aphids, and leaf-feeding caterpillars. The aphids have been identified as cowpea aphid and the caterpillars as one of the summer-active armyworm species, Spodoptera exigua (lesser armyworm). The concerns about these are for the potential for crop loss caused by direct feeding damage/defoliation or virus… Read more »
On the Darling Downs there have been a number of reports of common armyworm causing significant defoliation in sorghum, corn and millet. Jimbour grower John Alexander treated a severely defoliated sorghum crop two weeks ago. Millet and corn crops in the same area have also been affected. Although patchy, the outbreaks have the potential to cause significant yield loss if… Read more »
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 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 »
High rainfall and active plant growth have created perfect conditions for insects to build up in high numbers. On the Downs there have been reports of castor oil looper and common armyworm in plague numbers as well as other caterpillars including sorghum head caterpillar.
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.
Over the past couple of weeks there have been numerous reports of armyworm in both barley and wheat. The appearance of armyworm in wheat raises a number of questions: 1) Do they behave the same way in wheat as in barley in relation to the type of damage they cause 2) what is their damage potential and is there an… Read more »
Both Helicoverpa armigera and armyworm larvae are occurring together in wheat and barley. It is important to be able to separate the helicoverpa larvae from the armyworm larvae in order to determine whether the numbers are above or below threshold, and, if needed, to make the most appropriate decision about control options. Armyworm larvae have three white stripes on the… Read more »
With the current high value of barley, growers should closely monitor armyworm infestations as crops approach maturity. Armyworms are important pests in southern Queensland where they attack winter cereals, particularly barley and oats, in September and October. Larvae appear in plague proportions in some years, and are patchy in others. Head cutting by large larvae can lead to serious losses… Read more »