Larvacidal effect of some plant extracts against tomato leaf miner (Tuta absoluta Meyrick; Lepidoptera: Gelehiidae).
Tuta absoluta Meyrick (Lepidoptera: Gelehiidae) is a significant tomato pest, and chemical pesticides are used extensively for its control. Because of the adverse effects of chemical pesticides, researchers have been paying attention more to biopesticides. In this study, the larvicidal effects of the extracts of Tanacetum vulgare (Asteracea), Aleo vera (L.) and (Liliaceae) Tagetes patula L. (Asteracea) was determined and trials were conducted by using leaf dipping and pot methods. The leaf dipping method was conducted in a climate chamber, whereas the potting experiment was performed in the greenhouse. In all of the experiments, second-stage larvae were used to determine the larvicidal effects. According to the results obtained, the highest larvicidal effect and mortality rate was observed at the highest concentration of T. vulgare extract (86%, effect: 86.55%). The lowest mortality rate and the larvicidal effect was observed at the same concentration of T. patula extract (mortality: 79%, effect: 78.55%). In the pot experiment, the highest yield was seen in the Neem Azal T/S, followed by T. vulgare, A. vera and T. patula extracts. On the first day counts, the lowest insecticidal effect was obtained with the lowest concentration of T. patula extract. The extract of A. vera, T. vulgare and T. patula was effective in experiments carried out in pot and laboratory conditions on T. absoluta. It is suggested that more research be done on using these extracts as a biopesticide to control T. absoluta.