This invention entails a method to make a Tra-2 RNAi kernel sequence, and uses for this kernel sequence. The method includes the steps of amplifying an RNA recognition motive (RRM) DNA sequence from a Culcinae mosquito species, to obtain a first RRM DNA sequence of 240 base pairs; then reversely connecting the first RRM DNA sequence with a second RRM DNA sequence via an intron or a linker DNA sequence, in such a way that the second RRM DNA sequence forms an inverted sequence to the first RRM DNA sequence. Transcription of the two DNA sequences produces single strands of mRNA that can bind together to form a double strand hairpin mRNA structure. Other steps include inserting a tetracycline repressible transactivator, and an insect spermatogenesis promoter.