Spraying Too Much: Understanding the biology of the red headed flea beetle to inform IPM in nursery crops

View the project final report

Commodities

• Additional Plants: ornamentals

Practices

• Crop Production: nurseries
• Pest Management: integrated pest management

The red-headed flea beetle, Systena frontalis (Coleoptera: Chrysomelidae) is a key pest in nursery crops across the Southeastern US, costing millions of dollars for controlling this defoliator. Some nursery growers could spray up twice a week, during the peak of the season, to control this pest. Excessive use of insecticides contradicts all the notions on sustainable agriculture, negatively impacting the environment, non-target organisms and the wellbeing of growers and consumers. This research effort proposed to better understand the biology, phenology, and damage potential of this devastating beetle in ornamentals. Both a combination of in-field and greenhouse work let us elucidate the biology of this beetle. This proposal aids filling up information gaps on this pest, impacting the implementation of an IPM program to control this beetle. Seasonal monitoring was performed to determine times of the year where less spraying of insecticides may be needed. Peaks of adult activity were recorded in eastern Virginia during June, late July, and from late August to early September, indicating the possibility of three generations. Adult lures with phenylethyl alcohol were placed in the field to establish them as a method of cultural control to attract the red-headed flea beetles away from target crops. This alcohol lures were ineffective to attract adults. Foliar damage quantification based on adult density helped in ascertaining what damage quantity and type is being caused. As expected, there was a linear and positive relationship between adult density and percent defoliation of hydrangea leaves. Densities of five adults per plant resulted in an average of 4% defoliation at the leaf level. The ultimate goal for this project was to establish an IPM program for this pest, improving the sustainability of nursery systems, and reducing the overall use of insecticides to protect the systems involved. 

The major goal of this research effort was to increase knowledge of biology, ecology and management of the red-headed flea beetle under nursery conditions. Better informed decisions on pest control by growers will ultimately result in reduced operational costs, decreased insecticide use, and preservation of beneficial insects. The specific objectives for this proposal were as follows:

1) Document the phenology of adults under commercial nursery settings.

2) Compare the performance of yellow sticky cards vs. transparent sticky cards, with and without a lure of phenylethyl alcohol, to capture adults in commercial nurseries.

3) Document the foliar damage potential from different densities of adults within the canopy of hydrangea plants under greenhouse and non-choice assays.