Factors affecting the efficacy of capturing Adoxophyes orana by sex pheromone traps

Abstract:【Objective】The summer fruit tortrix moth (Adoxophyes orana Zhou et Fu) is one of the main pests in apple and peach orchards. Sex pheromone trapping has shown that the moths are not concentrat- ed in any particular habitat. Application of insect sex pheromones as a biological control technology has the advantages of high specificity, no pollution and safety for its natural enemies, and has received ever- increasing attention. A rational way of using synthetic sex pheromone on pest management takes great effect on reducing the use of pesticides. Insect sex pheromones have been successfully used in agricul- ture and forest pest management programs. To explore the scientific technology for monitoring Adoxo- phyes orana by using sex pheromones, the best combination of sex pheromone lures and traps were cho- sen, and the results improved the possibility to implement the specific control methods against Adoxo- phyes orana in orchard IPM.【Methods】The occurrence patterns of Adoxophyes orana were studied by sex pheromone traps in Zhengzhou area of Henan province after 3 years’continuous investigation (2016—2018). The effects of the types (triangle, basin, boat, cylindrical), placement locations (at height of 1 m, 1.5 m, 2 m), lure numbers (1, 2, 3, 4, 5), and intervals of sex pheromone traps (15 m, 25 m, 35 m, 45 m) on the efficacy of capturing Adoxophyes orana were examined. Hanging traps were placed on the external branches of the tree canopy, and the number of Adoxophyes orana captured by each trap was recorded every week. The trap position changed to reduce the error caused by the different insect population density in the orchard. Each treatment was repeated 4 times.【Results】The results showed  that Adoxophyes orana bred 4 generations yearly in Zhengzhou, Henan province, the period for trapping the adult moth lasted from April to September, over wintering generation began to emerge in the mid and late April, and the adult population reached the maximum peak in late April to early May. After overwintering, several generations of the moth reproduced with overlapping generations. The results showed the number of male adults trapped by the triangle trap (14.92±0.72) and basin trap (15.57±2.48) was significantly higher than the boat traps (6.36±2.20) and cylindrical trap (6.02±2.09) (p < 0.05), in which no significant difference was found in trapping effect between triangle- and basin-shape traps, and between boat- and cylindrical-shape traps, respectively. There was no significant difference in the trapping effect between the height of 2 m (15.98±1.12) and 1.5 m (14.32±0.36). The trapping effect of lures placed at height of 2 m was significantly higher than that of 1 m (10.94±2.97) (p < 0.05). The num- bers of Adoxophyes orana caught by traps with different number lures were: 1.75±0.05 (1 lure), 3.43± 0.23 (2 lures), 2.11±0.39 (3 lures), 2.22±0.21 (4 lures) and 2.39±0.30 (5 lures), and the trapping effect of 2 lures in each trap was extremely significantly higher than other number lures (p < 0.05). The amount of trapping was the least when 1 lure was set in the trap. There was no significant difference in the amounts of trapping after more lures (3, 4 or 5) were set in each trap (p > 0.05). The results showed that the inducement of pheromone to Adoxophyes orana could not increase with the increase of phero- mone. The daily amounts of trapping set at different interval of sex pheromone traps were 15 m (1.73± 0.24), 25m (1.94±0.26), 35m (2.64±0.36), and 45 m (2.08±0.08), respectively. The traps away from 35 m in distance had the largest trapping number than other interval. When the distance was less than 35m, the amount of traps increased with the the distance between traps. When the traps were placed away from 45 m in distance, the amount of traps decreased.【Conclusion】The factors affecting field trapping of Adoxophyes orana by sex pheromone were as follows: using a triangle or basin trap, placing the lures more than 1/2 of the height of the tree, setting 2 lures in each trap and setting 35 m as the interval, in or- der to achieve the best trapping effect on Adoxophyes orana. The present results could be referred in sci- entific monitoring Adoxophyes orana by sex pheromones.