Farm hygiene underpins the successful management of a number of major pests. The recent appearance of solonopsis mealybug has highlighted again the importance of farm hygiene. We already know from past experiences with silverleaf whitefly, aphids and bunchy top that it makes economic sense to keep on top of weeds and volunteer cotton. Good farm hygiene over winter is an investment in next season’s crop.
Outlined in today’s blog are the results for whitefly parasitism assessments, whitefly species composition and whitefly resistance testing from the 2009-2010 cotton season.
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.
Over the past week we have had several enquiries about large numbers of caterpillars destroying plants in home gardens. This pest has now been identified as castor oil looper – Achaea janata. While the entomology team does not generally report on home garden issues, this pest can also affect broadleaf crops such as soybeans and mungbeans. The castor oil looper… Read more »
We have fielded numerous enquiries this week from consultants who would like to assess levels of whitefly parasitism. This is achievable in the field with the use of a hand lens. Parasitism levels appear to be a little down from last year, but still good levels have been recovered. Parasitism so far has ranged from 50-90% in Emerald, 35% in… Read more »
Biosecurity Queensland has confirmed an outbreak of an exotic species of mealybug currently affecting cotton properties in Emerald is also present in cotton crops in the Burdekin region. The exotic species of mealy bug is commonly known as the Solenopsis mealybug (Phenacoccus solenopsis).
We have received numerous enquiries about whitefly in the last week especially from the MacIntrye and Lower Namoi areas. Shortages of chemicals to control whitefly is currently of major concern to many growers and consultants in this region. Many enquiries also relate to species identification. Whitefly samples identified from the MacIntyre and Lower Namoi areas have been 100% B biotype… Read more »
Distinguishing ‘brown’ stink bugs from each other. Adults brown stink bugs (Dictyotus caenosus) are shield shaped, matt brown, and smaller than green vegetable bug (GVB), about 7 – 8 mm long (Plate 1). They may be confused with glossy shield bug (Cermatulus nasalis) which is a slightly larger predatory bug, and with rice spotting bug (Eysarcoris distinctus) which is smaller… Read more »
While soybeans are more likely to be attacked by helicoverpa from flowering onwards, severe infestations can occur as early as the seedling stage. In recent years, severe early infestations have been reported on the Downs and in the coastal Burnett with the affected crops experiencing significant yield losses. The latest published thresholds for helicoverpa in vegetative soybeans (Rogers and Brier,… Read more »
However, in some years, very high pest activity results in more severe cob damage, with larvae often tunnelling into the sides of cobs. In such cases grain samples may contain fungus-affected grains and mycotoxins, causing a downgrade in the quality of harvested grain.
