Field cage assessment of feeding damage by Halyomorpha halys on kiwifruit orchards in China

Abstract

The brown marmorated stink bug (BMSB), Halyomorpha halys (Stal) (Hemiptera: Pentatomidae), is a polyphagous pest of fruit and vegetable crops. Kiwifruit is an economically important fruit, and occasional outbreaks of BMSB have been reported in kiwifruit orchards in China, Italy, and Greece. However, information on the types of damage and damage levels on fruit that BMSB can cause during the growing season are currently lacking. To address this, we conducted field experiments using exclusion cages to investigate feeding damage caused by BMSB to three kiwifruit cultivars [Actinidia chinensis var. deliciosa ‘Hayward’ (green), A. chinensis var. chinensis ‘Nongdajinmi’ (yellow), and A. chinensis var. deliciosa ‘Xuxiang’ (green)]. We also investigated damage levels at different insect and kiwifruit densities on ‘Hayward’. Results indicate both nymphs and adults caused green and white damage spots under the skin of kiwifruit. Green and white spots were found mixed or singly in all three cultivars. The proportion of each type of damage spot varied with the fruit development stage and the cultivar. The incidence of fruit damage was not significantly different among the cultivars (‘Hayward’ 76.9%, ‘Xuxiang’ 82.5%, ‘Nongdajinmi’ 73.5%); however, lower intensity of fruit damage was observed on ‘Nongdajinmi’. The incidence of fruit damage in ‘Hayward’ did not differ significantly among different insect/fruit densities, while intensity of fruit damage increased with increasing ratio of insects to fruit. The intensity of fruit damage significantly increased when four or more insects were introduced to cages when compared with two. These results provide key information on the characteristics of BMSB damage in kiwifruit.