Dynamics of the Adult Litchi Stink Bugs, Tessaratoma papillosa (Drury) (Hemiptera: Tessaratomidae), on Four Urban Tree Species in Taipei City

A two-year study, starting at the beginning of 2018, in Taipei City, was conducted to investigate the population dynamics of adult litchi stink bugs, Tessaratoma papillosa (Drury), in the trees on roadsides and in urban greenspaces, namely, Litchi chinensis Sonn., Dimocarpus longan Lour., Sapindus mukorossi Gaertn. and Koelreuteria henryi Dümmer, and deduce the relationship between the population dynamics and the photoperiod or climatic factors. The winter diapause of the adults might play an important role in the population dynamics and affect their movement among various host species. However, we also found that a warm winter and early-summer rainy season may affect the population size of stink bugs. There were significantly more adults in 2018 than in 2019 when comparing the periods from March to December of the two years. In a comparison of the four tree species, there were significantly more stink bugs on the longan trees than on the other trees, especially during winter. The results of this study might allow decision-makers to apply better control strategies based on the correct timing and targeting of tree species of this invasive pest in Taiwan.