Effects of Host Plants on Oviposition, Feeding and Population Growth Parameters of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

One of the main reasons for the reproductive success of tomato leafminer (TLM), Tuta absoluta, is having wide alternative host plants. In Ethiopia, information on the suitability of alternative hosts for its development from egg to adult and reproduction is lacking. Such information is useful to design an integrated pest management program. Thus, the oviposition and feeding preference of TLM for three cultivated hosts, tomato (Solanum lycopersicum L.), potato (Solanum tuberosum L.) and pepper (Capsicum annuum L.); and two wild hosts, grey bitter-apple (Solanum incanum L.) and jimsonweed (Datura stramonium L.); and their suitability for the pest in terms of population growth parameters were evaluated between December 2023 and April 2024 at Melkassa Center of the Ethiopian Institute of Agricultural Research (EIAR) in a randomized complete design. The TLM eggs were able to develop into adults on the host plants except pepper. The rate of survival from egg to adult on tomato, potato, grey bitter-apple and jimsonweed was 70.7, 68.7, 42.0 and 8%, respectively, without significant differences between tomato and potato. The pupal weight and fecundity of the pest when reared on these host plants differed significantly. The lowest values in net reproductive rate (R0 <1), intrinsic rate of natural increase (rm<0) and finite rate of natural increase (λ <1) were observed on jimsonweed, indicating less suitability of this host to this pest compared to tomato, potato and grey bitter-apple. The TLM larvae obtained from potato and grey bitter-apple resulted in a pupal weight of 3.6 and 3.3 mg, and egg to adult survival rate of 59 and 49%, respectively, when reared on tomato. The roles of host plants that sustain the development and reproduction of TLM need to be given due emphasis in planning and implementation of an integrated management program.