Bottom-up effects of various potato cultivars on the performance of Tuta absolut

The South American tomato leaf miner, Tuta absoluta (Lepidoptera: Gelechiidae) is a worldwide devastating insect pest of tomato. The pest has also been found to be damaging potato, but little is known about the performance on potato. To evaluate the adaptability of T. absoluta on potato and screen the resistant cultivars, the performance of T. absoluta was determined on four widely-grown potato cultivars (Qingshu No. 9 [QN9], Lishu No. 6 [LN6], Hezuo No. 88 [HN88] and Mila [MI]) in China using the age-stage two-sex life table, compared with tomato cultivar (Shouhe) as a control. The activity of several enzymes in the larvae were also determined. We found that T. absoluta could complete life cycles on the leaves and tubers of four potato cultivars, but was less harmful to tubers. The intrinsic rate of increase was the least on leaves of HN88, higher on leaves of QN9, LN6 and MI, and highest on tomato leaves. The lowest and highest fecundity of T. absoluta was recorded on the cultivar HN88 tubers and MI leaves, respectively. Moreover, the lowest pupal weight of T. absoluta was observed on the cultivar of QN9 leaves. The enzyme activities of the larvae feeding on difference cultivars did not show a clear pattern. In conclusion, T. absoluta showed high damage potential to potato, with the highest and lowest fitness to the potato cultivar MI and HN88, respectively. Considering bottom-up effects as a key driver in integrated pest management (IPM), the cultivars HN88 and QN9 could be preferably used in the IPM.