The effect of some attractıve plants on the effıcıency of black bean aphıd (Aphıs fabae scopolı) predators

Laboratory and field experiments were conducted from 1/10/2022 to 1/7/2023 to study the response of the Coccinella predator insects to attractant plants and their oils and to evaluate the efficiency of predators in controlling black bean aphids, Aphis fabae. Aphids and mummified predator insects were obtained from the fields of the College of Agriculture and Forestry, University of Mosul. Five attractant plants were used: pipon (Matricaria chamomilla), coriander (Coriandrum sativum), mint (Mentha piperita), basil (Ocimum basilicum), and radish (Raphanus sativus). The results were as follows: In the laboratory, pipon plants achieved a significantly higher (P<0.05) attraction rate for Coccinellid predators than the other plants studied, with an average of 55 ± 12.5. The order of attraction was from highest to lowest: pipon (55), coriander (50), radish (45), mint (25), and basil (15). The results of the evaluation of the attractiveness of different essential oils for Coccinellid predators in the laboratory showed that pipon plant oil was the most attractive essential oil (50 ± 22.36%). The order of attractiveness of the essential oils from highest to lowest was: pipon oil (50), radish oil (45), mint oil (35), basil oil (15), and coriander oil (40). The control treatment was the least attractive. The combined effects showed that the highest attraction rates were achieved in the laboratory when both the pipon plant and its essential oil were used together (52.5 ± 3.56%). This combination was more effective than combinations containing other plants and their essential oils. The control treatment had the lowest attraction rates (10 ± 0%). The effect of plants was also significantly higher (33.3 ± 19.14%) than the effect of essential oils on attracting predators, which was 8.29 ± 5.26%. Crops containing pipon oil showed the highest number of predatory beetles (13.5 ± 1.29), compared to the other treatments. The control treatment without essential oils had the lowest average number of predatory beetles (2 ± 1.11). The presence of black bean aphids was significantly reduced in the crops containing essential oils compared to the control treatment. While in the field, pipon oil achieved the highest rate of predator presence (13.5 ± 1.29). Coriander oil also achieved the lowest rate of black bean aphid presence (1.37 ± 1.57). A comparison of the plant and oil treatments in the field showed that pipon plants achieved the highest average attraction rate (55 ± 12.5), followed by pipon oil (50 ± 22.36) and coriander plants (50 ± 8.00). The control treatment had the lowest average attraction rate (10 ± 6.00). The combined effect of plants and oils showed that the highest attraction rates were achieved when both Pipon plants and essential oils were used together (52.5 ± 3.56). The control treatment had the lowest attraction rates (10 ± 0%). Crops containing radish plants also recorded the lowest average presence of black bean aphids (24.87 ± 20.43), followed immediately by the pipon plant treatment (28.62 ± 14.62). For the effect of oils on the density of black bean aphids, coriander oil achieved the lowest rate of presence of black bean aphids (1.37 ± 1.57). The field control treatment recorded the lowest rate of predators (2 ± 1.11) and the highest rate of black bean aphids (113.75 ± 27.62). The regression analysis's findings revealed that the model's R-squared value was 0.9418, indicating that it explained 94.18% of the variation in the number of predators. The model parameter estimates showed that temperature, humidity, and rainfall had positive coefficients of 2.78467, 0.38611, and 0.00593, respectively. The stepwise model had a large overall fit (p < 0.0001) with an R-squared value of 88.53%. The density of aphids also had a positive coefficient of 3.88, indicating a significant positive effect on predator numbers. The results of the regression analysis on mummy density showed that aphid density, predator density, temperature, humidity, and rainfall were all statistically significant indicators at the 1% probability level, with an R-squared value of 0.9157, indicating that the model explains 91.57% of the variation in the number of mummies.