Study on population dynamics and damages of Tuta absoluta on three common solanaceae vegetables in Ili, Xinjiang Uygur Autonomous Region

In order to develop a better control strategy for Tuta absoluta on different solanaceous vegetables, the population dynamics of T. absoluta on tomato, eggplant and pepper under two cultivation methods (open field and protected greenhouse) were investigated in Kukelanmu vegetable base of Kaerdun Township, Yining County, Yili Kazak Autonomous Prefecture for two consecutive years from 2023 to 2024, and the population dynamics of T. absoluta on three common solanaceous vegetables were compared. At the same time, the damage degree of T. absoluta to tomato, eggplant and pepper leaves was evaluated by the five-degree evaluation method of plant damage. The results showed that the damage degree of T. absoluta to tomato leaves was the highest. The number of leaves with a single leaf damage area more than 35% (V level) reached as high as 45.6% of the total number of leaves in the plant, and the average fruit-boring rate of tomato fruit reached as high as 7.8%. The damage degree of T. absoluta to eggplant leaves was relatively low, and the number of leaves with a single leaf damage area more than 35% (V level) reached as high as 4.2% of the total number of leaves, and no damage to eggplant fruit was found. T. absoluta was not found to damage pepper leaves and fruits. The maximum amount of adult, egg, larva and pupa of T. absoluta on tomato and eggplant was from June to August, and the number of these four stages on tomato was more than that on eggplant. The field investigation did not find the damage symptoms of T. absoluta on pepper, and the eggs, larvae and pupae of T. absoluta had not been detected. However, a large number of adults could be trapped in the pepper fields of open field and protected greenhouse. This could be due to the presence of Solanaceae weeds such as Solanum nigrum in the pepper field. On the other hand, it could be that tomatoes and eggplants were not planted around the pepper field, and the planting distance was less than the attraction distance of the sex lure (20 m). In summary, the T. absoluta in Ili area mainly appeared from June to August, and among the three vegetables, it mainly harmed tomato, followed by eggplant, and did not harm pepper at all. Different control strategies should be adopted. This study is helpful to detect and control the T. absoluta in time, reduce economic losses, and provide a theoretical basis for the development of comprehensive prevention and control technology for the major invasive pest T. absoluta.