Technical Abstract: Insect feeding and vectoring of viruses cause serious problems in sugarbeet production worldwide. In order to ameliorate insect and disease problems on sugarbeet, two seed treatments, Poncho Beta (60 g a.i. clothianidin + 8 g a.i. beta-cyfluthrin/100,000 seed) and Cruiser Tef (60 g a.i. thiamethoxam + 8 g a.i. tefluthrin/100,000 seed) were investigated (the neonicotinoid was tested alone in some trials). The two seed treatments and an untreated check were tested in a series of seven field trials from 2006 to 2008 along with various commercial sugarbeet cultivars in a randomized complete block design with eight replications per trial. Natural insect incidence and curly top symptoms were evaluated. Both Poncho and Cruiser provided significant reduction in curly top symptoms and incidence of spinach leafminer (Pegomya hyoscyami Panzer), black bean aphid (Aphis fabae Scopoli), and sugarbeet root aphid (Pemphigus betae Doane). At times Poncho performed better than Cruiser, but yield parameters for the two products were similar. When compared over six trials, the untreated check and Poncho Beta treatments averaged 74.5 and 81.7 t/ha, respectively. Neonicotinoid seed treatments will play an important role in disease and insect management in sugarbeet production, but should be viewed as a supplement to host resistance and not a substitute for it.