Disclosed are a nucleotide sequence and a method for controlling insect invasions, the isolated polynucleotide sequence comprising: (a) a polynucleotide sequence as shown in SEQ ID NO: 1, 2 or 3； or (b) a polynucleotide sequence hybridizing with the polynucleotide sequence defined in (a) under stringent conditions； or (c) a polynucleotide sequence having an identity of not less than 80% to the polynucleotide sequence defined in (a)； or (d) a polynucleotide sequence of at least 19 consecutive nucleotides of the polynucleotide sequence defined in (a), wherein a double-stranded RNA comprising at least one strand complementary to the polynucleotide sequence, when ingested by an insect pest from Hemiptera, inhibits growth of the insect pest； or (e) a complementary sequence of the polynucleotide sequence as defined in (a), (b), (c) or (d). The three target sequences for controlling an insect pest from Hemiptera, Lygus, have the advantages of efficiency, specificity, convenience and low cost.
