Solenopsis mealybug (Phenacoccus solenopsis) was first identified at Emerald and the Burdekin during the 2009-10 cotton growing season. This sucking pest causes leaf distortion, stunting and reduced boll size and number. Heavy infestations can lead to plant death. Solenopsis mealybugs also produce a honeydew which affects photosynthesis and leads to sooty mould development on lint. This pest has the potential… Read more »
Results for 2011-12 Monitoring for resistance in Silverleaf whitefly, collected in the 2011-12 cotton season, is now complete. Results show that resistance exists for Admiral® and bifenthrin (e.g. Talstar®) in horticulture but not in cotton while SLW remain susceptible to Pegasus® and Movento® In total 17 collections were made from Emerald, St George, Theodore, Moree and Narrabri for resistance monitoring…. Read more »
Implications for management in grains and pulses The insecticide resistance monitoring program for Helicoverpa aims to measure resistance frequencies of field populations collected from Central Queensland through to the Riverina area of NSW. Field collections of Helicoverpa eggs are reared in the laboratory and larvae are tested with doses of insecticide that are known to kill susceptible insects. Survivors are… Read more »
There are a number of canola crops in this season, and as the weather warms up the aphid numbers are building up in some of them. The aphids that colonise canola are most commonly the cabbage and the turnip aphid. There may also be a few green peach aphid present. The aphids colonise the terminal end of the flower spike… 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 »
As the cotton season draws to a close it is time to for the DAFF team working on Silverleaf whitefly (SLW) resistance monitoring to start making collections of whitefly from across the cotton-growing regions. Even if SLW numbers are below threshold, it is possible for the team to make collections of either nymphs (on leaves) or adults (using the suction… Read more »
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 »
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 »
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 »
