顏福成 張賜海 黃天福
Application of Sex Pheromone of Tomato Fruit Worm (Helicoverpa Armigera) in the Field
F. C. Yen, S. H. Chang and T. F. Huang
1. Six different combination of sex pheromones z-11-16 Ald, z-9-16 Ald and z-11-14 Ald were used to trap male moth of tomato fruit worm in January, 1986. Best result was observed in the ratio of 9:1:0 which is better than that by using 3 virgin females (138:30). The ratio of 8:1:1 was the next (74). The a-11-14 Ald seemed to be no effect.
2. With regard to the ratio of 9:1 (z-11-16 Ald : z-9-16 Ald), the dosage of 4 mg/trap obtained the best result from January to March in 1986, following 1.0-3.5 mg/trap. The result of less than 0.5 mg/trap was poor.
3. The effectiveness of sex pheromone could be lasted for more than 30 days.
4. For the efficacy of different types of dispensers, not much difference was observed between plastic dispenser and rubber dispenser.
5. For the landing points of the male moths trapped by sex pheromone, the percentages of these points within the range of 10 cm, 20 cm, 30 cm and 40 cm from the traps are 26.5%, 70.2%, 83.5% and 92.3%, respectively.
6. Different types of traps obtained different results. The water through trap and sticky paper types were better than Takeda trap and PET bottle types.
7. Among the different structures of PET bottle type traps, the type of two segments with the bottom open was the best. It is non-significant for trapping whether there is a inner bottle neck or not.
8. The effect of the different PET bottle type traps was poor than that of sticky type. This needs to be continuously studied.
9. The population dynamics of tomato fruit worm had two peaks each year in the peanut field in Tainan. These two peaks are from March to June, and from September to November. There are also two population peaks from May to June and from October to November in Paochung annually. The amount trapped in Paochung is much higher than that in Tainan.
10. The relationship between the amount of trapped male moths and larvae was significant in the peanut field. Usually 5 to 15 days after adult out-breaking in the first crop, 20 to 30 days in the second crop, a large number of male moths were trapped, and also a lot of larvae were found. It might be affected by the weather condition.
11. The optimum number of sex pheromone for mass trapping is 16 to 25 traps per hectare.
12. When we combine the three types of sex pheromones for mass-trapping of tomato fruit worm, tobacco cut worm and beet army worm, the distance between 2 traps must be greater than 2 meters.
When the disruption method is applied and 5 mg of sex pheromone per point is used in tomato field, the inhibition of attraction is only about 80% with the amounts of 1 g (200 points) and 2 g (400 points) per hectare. If 4 g (800 points) per hectare is used, the trapped percentage is more than 97% in 28 days, and more than 90% in 34 days. This shows the better result for the interruption.