Down-regulating gene expression in insect plants

An interfering ribonucleic acid (RNA) molecule which comprises at least one double-stranded region, wherein said double-stranded region comprises a sense RNA strand annealed by complementary basepairing to an antisense RNA strand, wherein the interfering RNA molecule upon uptake by an insect pest species is toxic to the insect pest species, wherein the interfering RNA molecule is encoded by a nucleic acid molecule comprising:

• (i) a nucleotide sequence that is at least 85% identical to any of SEQ ID NOs:
• 1, 21, or the complement thereof;
• (ii) a nucleotide sequence comprising at least 21 contiguous nucleotides of any of SEQ ID NOs:
• 1, 21, or the complement thereof;
• (iii) a nucleotide sequence that is at least 21 contiguous nucleotides and encodes an amino acid sequence that is encoded by al least 21 contiguous nucleotides of any of SEQ ID NOs:
• 1 or 21;
• or
• (iv) a nucleotide sequence that is at least 21 contiguous nucleotides and encodes an amino acid sequence that is at least 7 contiguous amino acids and is represented in SEQ ID NO:
• 206.