Microplitis demolitor is just one of many friendly fighters that battle to contain numbers of one of our most important pests, the corn earworm, Helicoverpa armigera. Corn earworm on grain sorghum is making its presence felt and many crops are being sprayed with Helicoverpa nucleopolyhedrovirus (NPV) to control above-threshold infestations of caterpillars. The current high value of grain sorghum (over… Read more »
Sorghum growers across the Darling Downs can expect to see an influx of the corn earworm, Helicoverpa armigera, in their flowering sorghum crops over the next few weeks. Growers are well equipped to deal with the problem in an environmentally friendly way. Moths are active and wanting to lay eggs on susceptible crops, and sorghum crops putting up heads are… Read more »
Corn earworm larvae on vegetative sorghum crops produce characteristic holes in the leaves after feeding in the throat of the plant. These tell-tale signs are of no great concern as this type of feeding will not affect crop yield. The recent presence of high numbers of corn earworm, Helicoverpa armigera, on winter cereals and chickpea could herald the beginning of… 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… Read more »
Control considerations – which product when? There is a range of products registered for helicoverpa control in chickpea. However, the use of synthetic pyrethroids is really only an option in regions where H. punctigera dominates, or where the population is predominantly made up of larvae smaller than 5 mm in length. The use of SPs against a predominantly H. armigera… Read more »
Corn earworm, Helicoverpa armigera, are frequently found in winter cereals but usually numbers are too low to warrant control. Occasionally, however, corn earworm numbers may be sufficient to cause economic damage. The high value of today’s grain is further reason to carefully check for grub infestations. It is not unusual to find both corn earworm and armyworm in cereal crops…. Read more »
A new guide to calculating economic thresholds available now Growers and agronomists are now able to calculate how much yield they will lose if they do not control an infestation of helicoverpa in chickpea. They can calculate the point at which it is economic to control an infestation based on the potential yield loss, their costs of control, the expected… Read more »
