Different population performances of Frankliniella occidentalis and Thrips hawaiiensis on flowers of two horticultural plants

Gardenia jasminoides and Rosa chinensis are economically important horticultural plants in China. Frankliniella occidentalis and Thrips hawaiiensis are serious coexisting pests that previously demonstrated opposite population trends on G. jasminoides and R. chinensis flowers. To further study the different performances between F. occidentalis and T. hawaiiensis, we investigated their population dynamics in the field (for 5 years) and their life history characteristics on the two flowers in the laboratory. In the field, the density of F. occidentalis was lower than that of T. hawaiiensis on G. jasminoides but was higher than that of T. hawaiiensis on R. chinensis. Under laboratory conditions, F. occidentalis showed significantly slower development, and lower survival and fecundity levels than T. hawaiiensis on G. jasminoides, but the opposite was true on R. chinensis. Significant differences in the net reproductive rate (R (0)) between F. occidentalis and T. hawaiiensis were observed, with respective values of 38.66 +/- 2.85 and 47.91 +/- 2.70 on G. jasminoides, and 55.64 +/- 2.15 and 32.45 +/- 2.16 on R. chinensis. The intrinsic rates of increase (r (m) ) of F. occidentalis and T. hawaiiensis were 0.156 +/- 0.008 and 0.198 +/- 0.007, respectively, on G. jasminoides, and 0.172 +/- 0.003 and 0.165 +/- 0.002, respectively, on R. chinensis. Thus, the performances of both thrips with respect to population size in the laboratory were in accordance with those in the field, suggesting that the innate capacity for insect population increases may directly impact their population dynamics in fields. Thus, the population performance of different thrips species on flowers is species-dependent, which could be exploited in thrips control programs by breeding pest-resistant cultivars.