The Asian plant bug Stethoconus praefectus (Distant) (Heteroptera: Miridae) was recently discovered in Florida preying on the avocado lace bug, Pseudacysta perseae (Heidemann) (Heteroptera: Tingidae). Its life cycle and effectiveness as a predator of P. perseae were investigated at 26 ±I°C, 60 ± 5 RH, and 12: 12 (L: D) under laboratory conditions. Stethoconus praefectus developed from egg to adult in 16.5 ± 0.2 d. On average, the first 4 instars consumed 2 to 4 prey per day, whereas the last 2 instars consumed 2 to 7 lace bugs per day. Stethoconus praefectus was observed in the field from Aug through Dec 2007.