Key Points
- Gaucho and Poncho gave good control of black beetle adults. Cruiser at either the rate currently registered for Agentine stem weevil or the higher rate did not give adequate control
- Poncho gave slightly better control of Argentine stem weevil larvae than Gaucho which in turn was better than either rate of Cruiser
- There were differences in the amount of insect damage on different hybrids. The hybrid that emerged the earliest sustained the most damage since initially it was the only food source available to the pests
- In a pot trial, spray applications of Fastac to the soil surface gave the best control of black beetle in the absence of rain and Karate Zeon gave the best control after 5mm of rain. Further trials are needed to confirm the response under field conditions