Category Archives: helicoverpa

Early Season Helicoverpa issues and the use of NPV to control larvae

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Helicoverpa populations have started with a bang this season.  One or more larvae per plant are common in pre-flowering sorghum, corn and cotton. However, early flowering sorghum crops are carrying up to 10 larvae per head.  Corn and sorghum (monocot crops) host only Helicoverpa armigera, not H. punctigera – which has implications for control.  Some key issues relevant to dealing… Read more »

Helicoverpa larvae surviving in failed chickpea crops may be a threat to the following crop

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With some chickpea crops being sprayed out, rather than harvested, there are reports of helicoverpa larvae surviving on crop residues. The survival of larvae, particularly large late instar larvae, poses a threat to subsequent crops that may be sown directly into the chickpea residues. It is important to check for surviving larvae under the chickpea residues before the next crop… Read more »

Managing Helicoverpa softly in vegetative soybeans

 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 »

Chemigation for corn earworm control

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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.

Refresher on managing helicoverpa in chickpea

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With the approach of spring, helicoverpa start to become active. In CQ, chickpea crops are attractive to moths, and it is timely to revisit some of the key points related to making decisions about control of this pest in crops.In this article, I wanted to discuss a couple of the recommendations which some growers and agronomists have found a bit… Read more »

Latest helicoverpa thresholds for mungbeans

Revised thresholds for helicoverpa in flowering/podding mungbeans are based on a rate of damage of 35 kg/ha per larva per square metre in podding crops. The new thresholds are nearly double the old threshold of 1/m2, and make allowances for variations in control costs and crop value. For a typical scenario with pesticide control (including aerial application) costing $40/ha and… Read more »

New Helicoverpa thresholds in vegetative soybeans

The new economic threshold for Helicoverpa in vegetative soybeans is 8 larvae per sqare metre and replaces the old 33% defoliation threshold. The new threshold is based on field trials conducted by John Rogers (formerly with DPI&F at Kingaroy). These field trials show that approximately 7.5 larvae per square metre can be tolerated with no yield loss, but that severe… Read more »

Bring on NPV against grubs on grain sorghum

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Every year caterpillars of the corn earworm (helicoverpa), Helicoverpa armigera, cause losses to sorghum crops. Regular inspection during flowering is important to detect caterpillar infestations and properly time control measures. Pre-flowering heads of grain sorghum are very attractive to egg-laying moths of the corn earworm. On any individual head, most eggs are laid prior to the start of flowering, as… Read more »

Managing Helicoverpa larvae in chickpea crops close to dessication and harvest.

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Over the last week or so we have received a number of enquiries about how best to manage new egg-lays, and populations of small larvae, in chickpea crops that are close to dessication and senescing. Of most concern are crops that still have reasonable areas of green crop in them, and what the likelihood of damage is if the weather… Read more »

Helicoverpa management in chickpea – a refresher

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A comprehensive overview of Helicoverpa management in chickpea can be found in the DPI&F brochure Helicoverpa management in chickpea (2007). Key management decisions The following is an excerpt from the Helicoverpa management in chickpea brochure, and deals specificially with determining whether an infestation of helicoverpa warrants control – based on the economics of potential yield loss vs cost of control…. Read more »