Reports of increasing numbers of whitefly are filtering in from across the Downs. In some cases, numbers are sufficient to suggest that control of Silverleaf Whitefly (SLW) may be warranted. Correct identification and regular monitoring of populations is essential to determine if intervention is necessary. Which whiteflies are out there? Results of whitefly samples identified from Downs cotton crops… Read more »
There is an increasing number of reports of whitefly in cotton crops on the Downs. Typically, whitefly start appearing in crops in mid to late summer, once populations have built up on weed hosts or other host crops (e.g. sunflower) adjacent to cotton crops.So far this season we have been able to make collections of whitefly adults and immatures (scale)… Read more »
As many of the early sorghum crops reach physiological maturity, and approach harvest, questions are being asked as to whether it is necessary to control large populations of nymphs in these crops. More specifically, whether these RGB will cause any damage to the maturing grain between physiological maturity and harvest. Photo: Dave Murray (BigBug) out looking at a sorghum… Read more »
Adam Hardy Senior Entomologist, Queensland Department of Primary Industries and Fisheries, Toowoomba. Photo: Adam Hardy (right) and Bernie Franzmann inspecting midge rating trials. Over the last decade sorghum midge have not caused many headaches for sorghum growers. However, staggered sorghum plantings mean that sorghum midge are likely to be found building up in numbers in later planted sorghum… Read more »
Rutherglen bug infestations of grain sorghum This season we are seeing large infestations of Rutherglen bug (Nysius vinitor) (RGB) in sorghum crops from Central Queensland to the Downs, and further south. The large infestations are most likely a result of storm activity and the growth of weed hosts on which they breed up. RGB are very mobile, with large numbers… Read more »
Some issues have recently been raised on the Darling Downs regarding the use of Helicoverpa nucleopolyhedrovirus (NPV) against corn earworm on grain sorghum. These issues involve the delay in time to kill and the level of control not necessarily meeting growers’ expectations. Seasonal conditions The last couple of weeks on the Downs have been cooler than normal. The average daily… Read more »
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 »
Rutherglen bug (Nysius vinitor)(RGB) is one of the insect species that arrives in crops in spring in large numbers, usually in association with storm activity. You may also have seen them on your windows and screens (and around the lights) at home in recent days. It is likely that the bugs are moving around in the environment, perhaps even transported… 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 »