Tobacco as a trap crop for the tobacco budworm in cotton

Authors: Tillman, Patricia - Glynn

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/5/1999
Publication Date: N/A
Citation: Tillman, P.G. 1999. Tobacco as a trap crop for the tobacco budworm in cotton. Proceedings of the Beltwide Cotton Conference. p. 1201-1203.

Interpretive Summary: The tobacco budworm is an important leaf feeding insect pest of cotton, and worm infestations of greater than 10% significantly reduce yields. I am actively looking for methods to minimize damage by this insect while reducing the use of insecticides. The tobacco budworm is the predominate noctuid in tobacco and can be found feeding on tobacco in high numbers. The purpose of this study was to determine if planting strips of tobacco in cotton could be an effective control measure by trapping these insect pests in tobacco. In 1997, small (1.1 acre) field plots of cotton inter-planted with tobacco were established. The numbers of tobacco budworm eggs and larvae were monitored on tobacco and cotton throughout the growing season. Over the season the level of tobacco budworm larval infestation in cotton was relatively low, being nonexistent for the first three peak egg laying periods and never reaching higher than 0.08 larvae per plant after the last oviposition period. These results indicate that the tobacco budworm is more attracted to tobacco than cotton, and based on the affinity of this pest to tobacco, inter-planting tobacco in cotton could be an effective means minimizing tobacco budworm damage in cotton.

Technical Abstract: The ability of tobacco to serve as a trap crop for the tobacco budworm (Heliothis virescens) in cotton was investigated in Aliceville, AL in 1997. Strips of tobacco, 2 rows by 100 feet, were planted in the center of a 1.1 acre cotton field plot in a randomized block design with four replications. Using whole plant sampling to monitor eggs and immature tobacco budworms, it was determined that peak egg laying occurred in tobacco on 3 June, 23 June, 10 July, and 1 August 1997. Tobacco budworms were present only in tobacco during the first egg-laying period. On 23 June and 4 July, tobacco budworm eggs were found in tobacco and cotton although mean number of eggs per plant was much higher in tobacco than in cotton. No larvae were observed in cotton until the last egg laying period. By 14 August, when sixth instar tobacco budworms were present in tobacco and cotton, the mean number of tobacco budworm larvae per plant was much higher in tobacco than in cotton. These results indicate that the tobacco budworm is more attracted to tobacco than cotton, and thus tobacco could be an effective trap crop for managing this pest in cotton.