The invention provides constructs and methods of screening for constructs useful in conferring resistance in plants to pests by gene silencing. The invention also provides pest-resistant plants transformed with the present constructs. One screening method of the invention comprises the steps of: selecting at least one pest target nucleotide sequence, producing a plurality of dsRNA test agents that target the pest target nucleotide sequence, testing and scoring the plurality of dsRNA test agents for toxicity to the pest, and producing a silencing construct based on a superior-scoring test agent.
