Abstract: Pea aphid: Acyrthosiphon pisum (Harris) Producers rely on dimethoate for control of the pea aphid in field peas.Impending restrictions on its use require assessment of potential alternatives to dimethoate.A field trial was conducted during the summer of 2005 at the University of Idaho Parker Research Farm east of Moscow, Id.Field peas (var.'Joel') were planted on 1 May.Plots 5 × 1 m were planted with 1-m bare soil borders in a CRB design with 10 treatments and four replications.Pea aphids were counted on 10 randomly selected stems in each plot on 7 Jul and test materials were applied on the following day using a CO 2 -powered backpack sprayer.All materials were applied in 1 liter of water with Syn-Tac buffer and spreader sticker.Rates followed label recommendations where applicable or company representative recommendations for products not registered for use on field peas.Nine products were tested.The treatments included a control with the Syn-Tac only.Aphids were counted on a sample of 10 stems from each plot on 14 Jul (7 DAT) and again on 22 Jul (14 DAT).Plots were harvested from each plot by combine on 15 Aug and the cleaned seed was dried at 30°C for 1 wk before being weighed to estimate yield.ANOVA was used to assess effect of treatment on aphids per stem at 7 and 14 DAT and on yield (calculated as lb/acre).