Feeding injury of the azalea lace bug (Heteroptera: Tingidae)

Abstract

Azalea lace bug, Stephanitis pyrioides (Scott), feeding rates were investigated in controlled laboratory bioassays. Individual newly-eclosed nymphs were transferred to cut stems of 'Girard's Rose' azaleas and maintained at either 20°C for 26°C for the duration of their lifetimes. Feeding rates, determined using computer assisted image area analysis, were calculated for both nymphs and adults. In both trials, females caused significantly more feeding injury per day than males. However, the overall amount of injury inflicted during lace bug lifetimes was similar for males and females at both temperatures. During adulthood, feeding injury by individual lace bugs resulted in a mean (±SD) of 6.35 ± 4,61 cm2 leaf area injury at 20°C and 3.93 ± 2.06 cm2 leaf area injury at 26°C. Nymphal feeding was a small fraction of the injury inflicted by the adults and averaged 0.43 ± 0.15 cm2 at 20°C and 0.3 ± 0.10 cm2 at 26°C. The determination of azalea lace bug feeding-injury potential is critical to the development of decision-making guidelines.