Methods and compositions of insect control

Abstract

The invention describes recombinant DNA sequences transcribed into RNA constructs capable of forming Virus Like Particles (VLPs) suitable for insect control applications.

What is claimed is: 
     
         1 . A virus-like-particle (VLP) for controlling target insects, the VLP comprising a bacteriophage capsid protein encapsidating an RNA transcript comprising at least one bacteriophage pac sequence coupled to an RNAi precursor sequence targeted against a gene transcript of the insect to suppress expression of the gene in the insect. 
     
     
         2 . The VLP of  claim 1 , wherein the bacteriophage capsid protein derives from a levivirus. 
     
     
         3 . The VLP of  claim 2 , wherein the levivirus is Qβ. 
     
     
         4 . The VLP of  claim 2 , wherein the levivirus is MS2. 
     
     
         5 . The VLP of  claim 1 , wherein the RNAi precursor forms an siRNA. 
     
     
         6 . The VLP of  claim 1 , wherein the RNAi precursor forms an antisense RNA. 
     
     
         7 . The VLP of  claim 1 , wherein the RNA transcript comprises a first bacteriophage pac site, followed by an antisense sequence of the gene, followed by an RNA sequence capable of forming a single-stranded loop, followed by a sense sequence complementary to the antisense sequence of the gene, followed by a second bacteriophage pac site. 
     
     
         8 . The VLP of  claim 1 , wherein the RNA transcript comprises a bacteriophage pac site, followed by an antisense sequence of the gene, optionally followed by one or more bacteriophage pac sites. 
     
     
         9 . The VLP of  claim 1 , wherein the gene is an essential gene. 
     
     
         10 . The VLP of  claim 9 , wherein the essential gene is a gene controlling a larval development event, a gene encoding cellular structural components, or a gene encoding nucleic acid replication, transcription, or translation. 
     
     
         11 . The VLP of  claim 9 , wherein suppression of the essential gene results in death of the insect. 
     
     
         12 . The VLP of  claim 9 , wherein suppression of the essential gene results in the production of sterile off-spring. 
     
     
         13 . The VLP of  claim 9 , wherein the essential gene encodes β-actin. 
     
     
         14 . The VLP of  claim 1 , wherein the target insect is a Lepidopteran insect. 
     
     
         15 . The VLP of  claim 1 , wherein the target insect is a Coleopteran insect. 
     
     
         16 . The VLP of  claim 15 , wherein the Coleopteran insect is bark beetle, elm leaf beetle, Asian longhorn beetle, death watch beetle, mountain pine beetle, coconut hispine beetle, a corn rootworm, or Colorado potato beetle. 
     
     
         17 . The VLP of  claim 1 , wherein the target insect is Colorado potato beetle. 
     
     
         18 . The VLP of  claim 17 , wherein the gene encodes β-actin, and the RNAi precursor sequence is encoded by nucleotides 314-1219 of SEQ ID NO: 6. 
     
     
         19 . The VLP of  claim 17 , wherein the gene encodes β-actin, and the RNAi precursor sequence is encoded by nucleotides 317-820 of SEQ ID NO: 9. 
     
     
         20 . A combination of two or more VLPs of  claim 1 , wherein each RNAi precursor sequence is targeted against a different gene transcript of the insect to suppress expression of each targeted gene in the insect.