- Agronomic: corn, sorghum (milo), wheat
- Education and Training: demonstration
- Pest Management: biological control
[Note to online version: The report for this project includes graphs that could not be included here. Please see attachments below for a scan of the complete report and inclusion of graphs.]
The bindweed moth, Tyta luctuosa, was shown to successfully overwinter in Kansas for two consecutive years. However, survival varied considerably among and within locations in Kansas. In 1994-95, the average rate of survival, from the overwintering cocoon stage to fully emerged adult moths capable of flight, ranged from 0 to 23 percent. These findings were similar to those obtained in 1993-94 (range of survival: 0 to 20 percent). The highest survival in a single cage was 64%. Moth survival was no higher at southern sites than at northern ones suggesting that this bindweed enemy may be adapted to cold climates. Very few moths were recovered in a largescale field experiment designed to assess dispersal. Therefore, we began studies to identify the volatile chemicals produced by female moths that are used as sex attractants. Our rationale was that a species-specific sex attractant would be a useful tool for monitoring dispersal. Two major compounds were identified which elicit a response from males. A field experiment revealed that moderately high densities (about 75/m2) of large T. luctuosa caterpillars are necessary for complete defoliation of bindweed in the field. A greenhouse experiment showed that younger (smaller) bindweed plants not only are defoliated by fewer caterpillars, but that the rate of root growth and refoliation is slower when younger plants are damaged. Also, the greater the defoliation of any aged plant, the slower the recovery. Through presentations, publications, tours, radio shows, press releases, and individual on-farm training sessions, we educated large numbers of farmers, county weed personnel, and the general public about our biological control research efforts for field bindweed. These activities have increased awareness of nonpesticide alternatives for managing weeds, and the potential of using natural enemies to control field bindweed, an extremely serious pest in the Midwest and throughout the United States. Dissemination of our project goals and research findings also has led to cooperation from local farmers.
1. To evaluate the overwintering potential of the gall mite, A. malherbe, and the moth T. luctuosa, in different climatic zones within the North Central Region.
2. To determine the dispersal ability of the moth (T. luctuosa) at several release sites.
3. To determine the effects of moth (caterpillar) introductions on field bindweed growth, and determine the infestation levels necessary to ensure detrimental effects to field bindweed.
4. To investigate and quantify field bindweed population reduction by the moth (caterpillar).
Grower training and dissemination of knowledge:
5. To train and involve farmers with on-farm releases, surveying, and monitoring of the biological control agent, and in the evaluation of success.
6. To disseminate knowledge of the symptomology, ecology, and biology of moth to farmers and farmer organizations, extension personnel, other researchers, and those concerned with noxious weed control.